# Poorman Mutli-Lux setup method



## download

*Poorman Mutli-LED setup method*

I found some interesting setup method to use the cheap driver board like 7135.
It can be used multi Seoul P7 or Cree, 
like 2x li-ion to 2x LED or 3x li-ion to 3x LED.
It works quite well for me. Hope it helps you too.

The Cree XM-L have much lower Vin, 7135 does not work like 3x XM-L. (May-2012)






Each P7 can get 2.8A !!!
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Each LED get 1.4A !!!





3 wires only.


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## Bimmerboy

Download - Very interesting. Can you tell us more about this setup?


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## download

The DIY multi-level driver is same as NetKidz & StefanFS had posted.

https://www.candlepowerforums.com/threads/192677

https://www.candlepowerforums.com/threads/195358

My wiring way to use it as multi-led only.
Use same driver to drive more than one LED.
The driver control one LED only, the other LED just follow the current.
Under one condition: 1x Li-ion or 3x NiMH to 1x LED.
Simple & Cheap.


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## Bimmerboy

After reading those two threads, plus looking at the above diagrams, I'm still confused! :help:

Some questions:

Are you using a single 8 X 7135 board, or the controller/slave setup ?

How is it possible to put that much Vbatt into this? I thought the 7135 boards have a max input of 6V. Does your discovery mean it's 6V for each P7? If so, that's a pretty damn cool discovery.

In your first diagram, does the single P7 (connected to driver out) run in parallel or series with the other two P7's (connect to driver in)? I'm assuming series, because Vin would match the total emitter Vf, but I'm not understanding the diagram. EDIT: Think I figured it out... they'd be in series because driver in to driver out *is* in series. Correct?

Hoping to understand this setup, because it could be EXACTLY what I need to regulate 3 or 4 X P7 with 4 X Emoli.

Thanks, Download!


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## download

Bimmerboy, 
I would suggest you try single 7135x4 board first, ( just half of current go though the LED ) muti-level or not, my setting is same as NetKidz & StefanFS wiring method 2.8A. 

If you use 4 X Emoli, your driver connect 1x P7 and 3x P7 serial outside will be fine. ( 1 li-ion serve 1 LED only )

I tried & run for a while. It works quite OK for me.
eg: 3x P7 - The driver handle 1x li-ion power only, the serial P7 x2 share the 2x li-ion voltage, and all LED react the same function of the driving LED.

Hope this helps.


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## Bimmerboy

I think I'm beginning to see the light. 

The extra P7's connected to the "driver in" side are providing the voltage drop so that the board itself only sees the Vbatt of one Li-ion. Do I have that correct?

If so, that means you can't use 4 X Li-ion for three P7's in an attempt to get full regulation throughout the entire runtime, but that cloud has a silver lining anyway, since you'd never know when the batteries are getting too drained. The light wouldn't dim until the batteries were being damaged. So, there's sort of a built-in protection here with a 1:1 setup... our eyes. 

I definitely vote for this as "killer find of the month", maybe the year! A cheap, multiple P7 driver that seems to be working well. Totally surprised there's been no reaction to this.

Thanks again, Download. This sounds excellent! :thumbsup:

P.S. The heck with half current... I'm going straight for 2.8A!  I'm also thinking of using a D2DIM with this.


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## Doh!Nut

I am glad I found this, I was just about to post a question on the similar circuit, I had a look at the data sheet http://www.micro-bridge.com/data/ADD/AMC7135.pdf and saw that unlike most drivers that have four connections and the LEDout is not the same as the Batt Neg.

The AMC7135 has only three connections, with a common ground so whatever goes through the LED comes out the ground (and straight into the next LED :twothumbs)

This means that I could have a 3 P7 light running from 12v NiMh pack

Nick


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## download

Bimmerboy, You do see it, 4x P7 is very bright light.
D2DIM should work better for direct drive, only need more trick to wire extra control switch.
This wiring method is just easier only. 

Nick, in my test result, the multi-level driver did not survive to drive more the 3x Ni-MH per LED in 3 x LED setting. (I took out all diode to gain more voltage) 
I would suggest 3 P7 run 9 Ni-MH Max. only.

Cheers! :wave:


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## jeffosborne

From the AMC7135 data sheet:

*Supply voltage range 2.7V ~ 6V*

You are putting 10.8 volts nominal on a device that likes only up to 6 volts.

Have you TRIED the circuit you are proposing?
Anybody read the data sheets?

Warm regards,
Jeff O.


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## download

Both of wiring method I am using right now.
It works fine for me. Just share this little finding.


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## Doh!Nut

I am a little surprised that did not work with 4 NiMh per LED, but was half thinking about the circuit I was considering where the output of one driver went to the Vin (or Vdd) of the next stacked driver. That would be within the voltage specs but would be wasting lots of power.


The worst case for downloads circuit above is that you have low Vf LED, say 3.2V

So a fresh 12v Pack gives 14+v 
14v minus two times 3.2v gives 8.1v accross the driver - way off spec. You would have to drop two or three cells to bring it back down to spec. (as download said)

Four P7 (Gulp:devil

14.5v - (3*3.2v) = 4.9 accross driver (worst case)
Running condition
12.5 - (3 * 3.7v) = 1.4v accross driver and LED- ie it wont work .
Even if the driver did not drop any voltage accross itself and the voltage was devided equally that would leave 3.1v accross each LED, not enough for 350ma.

If I want to use this in a torch with existing 12v NiMh pack maybe I will have to get a circuit, and find the actual vf of the 3 P7s and put in a small resistor.

N


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## download

I mean the multi-level circuit IC will not survive, not AMC7135, 7135 just overheat, cutdown the power & flash. It will not die easily.

You may try this:

(P7 + 7135 with multi-level) Serial (P7 + 7135) Serial (P7 + 7135) -> 12V

Each 7135 board have diode to drop the voltage a little, should work now.


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## OldNick

Download

This is very clever. I believe you have tried this and it works, but I am completely puzzled. :huh:

Simple circuit, but I don't get the principles. What does that board do that allows you to connect the Bat (+) to the two lower LEDs (-) that are not driven by the board (the "slaves")? It's effectively in series with the battery and boosting the volts? Or is it sharing the volts between the driver/LEd combo and the slave LEDs?

Why do the lower ("slave") LEDs follow the current of the two that are actually driven?

Also, if you used a single board instead of the parallel version, I assume you could use the board to drive, say, just 2 Crees "in series" and not the paralleled version you have.

Given that I actually do not want to drive my Crees at 1400mA, how do you use this? Do you have a multi-stage board, and not use high, or do I use one of the lower-current boards (which I think have only 3 of the ICs on them rather than 4)

I would appreciate any help from you (or anyone) about this.

Nick (the second)


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## Mr Happy

OldNick said:


> This is very clever. I believe you have tried this and it works, but I am completely puzzled.
> 
> ...
> 
> I would appreciate any help from you (or anyone) about this.


I did not see this thread earlier, but it looks like a very creative use of the driver.

It works because the 7135 is a linear current regulator (in other words it is like a fancy variable resistor in the circuit). Because it is a linear regulator, the current everywhere in the circuit is the same, just as if it were a simple resistor.

In the first circuit then, all three P7's see whatever current the 7135 is set to, for example 2.8 A.

Now let's look at the voltages. When fully charged, three Li-ions in series produce about 12 V. On the supply side of the 7135 we have two P7's in series. Each of these will drop their Vf, which for the sake of example we might assume to be 3.5 V. Therefore the voltage seen on the input side of the 7135 will be 12 - 2 x 3.5 = 5 V. We therefore are within the allowable input range of not more than 6.0 V. Lastly, the 5 V input provides enough margin to drive the P7 on the output, assuming the same Vf of 3.5 V.

Out of curiosity, we can take the worst case when the battery is discharged and the P7's happen to have a higher Vf of 3.7 V. Close to discharge the battery will have a voltage nearer to 9 V than 12 V. From this we subtract 2 x 3.7 V giving 1.6 V. Clearly 1.6 V on the input to the 7135 is nowhere near enough to drive the output LED, so all the P7's will have shut off long before the battery gets this low.

As a result, the setup will not be able to extract all the charge from the battery, but on the good side it will protect against over discharge and prolong the life of the cells.

The second circuit can be analyzed in a similar way, except that now two LED's have been put in parallel. The trouble here is that if the two LED's have different Vf values, the current will not be equally distributed between them. Worse, if one gets hotter than the other the imbalance will tip further in the unequal direction.

It is not typically advised to put LED's in parallel because of this problem of current balancing. It may work but it's not a robust arrangement.


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## download

Hi OldNick,

I updated the diagrams for protected 18650 li-ion only, this is exactly what I am actually using.

The 7135 board transfer the extra voltage to heat before feeding LED. (like 4x 7135 ~1.2A to LED)

Because the Voltage of my Li-ion and LED Vin is close. So the extra voltage of multi-Li-ion is still OK for 7135. But not much.
If you get ultra low voltage of LED, result may be different.

In actual finding, 3x P7 diagram, the (two lower LEDs) share most the voltage of 2x li-ion, the driver take care 1x li-ion with little extra, when the muli-level driver switch dim, it limited the current of whole circuit, so all the led dim as same level. 

In 4 lux diagram, mainly use 2x Li-ion, it need 2x LED in serial to share it.
Parallel extra LED are just share the current of 8x 7135, not a must in 3x 7135.
If you use 2x LED only, wire LED like diagram, (no more extra parallel LED) one of the LED use (3x 7135) for 2x Li-ion is fine. Each LED got ~0.9A.


Mr Happy, 
You said better than me. :thumbsup:
In the real world, when the battery voltage lower than LED, driver run as direct driver and LED will run lower Vf too. It will drain all the battery dry till protected circuit works. 

Hope this helps!


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## OldNick

Ok. Thanks for the replies from both of you. My brain needed a kick.

I am OK with electrics, but just coming up to speed on these sort of current regulators, as distinct from voltage regulators.

I get the shared current. The 7135s actually allow a current by raising and lowering voltage then. As you say, a smart resistor. So as long as the volts left over from the "free" LEDs is within the volts of the 7135s, all stages will work. Within that range, the 7135s share the voltage across the circuit to maintain the current. 

But for all of me, the two "free" P7 LEDs (and the free ones in the Cree cct) are in reverse polarity. The Positive of the battery goes to the Negative side of the LEDs.

Sorry if I am missing something (apart from the functioning grey matter)

Nick


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## Mr Happy

OldNick said:


> But for all of me, the two "free" P7 LEDs (and the free ones in the Cree cct) are in reverse polarity. The Positive of the battery goes to the Negative side of the LEDs.


I think you are right. I noticed that too, but I didn't want to make my post any longer than it already was.

The positive (anode) side of the LED should be facing the positive (+) terminal of the battery. The LEDs do all appear to be backwards in the diagrams. The red and black coloring of the wires seems a bit out of place too...


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## OldNick

Oh good...for me anyway.

I reckon the LED that is actually driven by the board is OK for polarity. It's just that the connection to the centre + of the board is "blocked" by the board. It's difficult to draw that bit without either what we see or having the LED connected to both centre and edge, or look that way.

Download : Care to clear this up? As far as I am concerned, the idea is brilliant whether you have got it wrong in the drawing or not, and if the drawing is correct, then I need help to understand.

Nick


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## download

, really sorry, corrected the diagram uploaded.


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## OldNick

download said:


> , really sorry, corrected the diagram uploaded.



Bad luck, mate. Thanks for that. Still clever stuff. :twothumbs I am going to work with this. Sort of a $2 buckpuck! <G>

I give you an , not a  <G>

Nick


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## OldNick

download said:


> Hi OldNick,
> 
> I updated the diagrams for protected 18650 li-ion only, this is exactly what I am actually using.



Download

Are you saying it will not work with AAs?

You had them there at first and that is what I was going to use (I have them). But if they are no good, then I will have a think.


Nick

Nick

Nick <G>


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## Mr Happy

It will work with any batteries as long as you match the voltages correctly. Use my earlier post to give you an idea of how to work it out.


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## 07accordEX

i have a quick question if you are using 1x li-ion per p7 how come the its 1x li-ion per 2x crees?

how would i wire it to use 4x li-ions for 4 crees?


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## OldNick

Mr Happy said:


> It will work with any batteries as long as you match the voltages correctly. Use my earlier post to give you an idea of how to work it out.



Hi MrHappy

I can work it out OK, once I grasped the idea of the "smart VReg-for-current" that the 7135 is.

I was asking _because_ it looked OK, but Download had specifically removed the AAs from the drawing.

Nick


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## Mr Happy

OldNick said:


> I was asking _because_ it looked OK, but Download had specifically removed the AAs from the drawing.


I was just confirming. No dig intended


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## Mr Happy

07accordEX said:


> i have a quick question if you are using 1x li-ion per p7 how come the its 1x li-ion per 2x crees?
> 
> how would i wire it to use 4x li-ions for 4 crees?


Here's a quick answer:

Two Li-ions will supply from 8 - 6 V depending on the state of charge. The Crees in the diagram are the high output R2 variety, and these tend to have a higher Vf, maybe 4 V or more at 700 mA. So you do the calculation in the same way; take the 8 V from the battery, subtract the 4 V Vf, and therefore the regulator sees a 4 V input. The numbers are within range, so the circuit works.

My feeling is that with that setup there is little margin of excess voltage. If the Cree R2s happened to have a Vf of 4.2 V, it would be very difficult to get maximum brightness out of them, especially as the battery discharged below 8 V.

Also, as I mentioned above, it is not usually a good thing to put LEDs in parallel. Unless you carefully match the Vf's, you may get uneven current distribution.


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## OldNick

07accordEX said:


> i have a quick question if you are using 1x li-ion per p7 how come the its 1x li-ion per 2x crees?
> 
> how would i wire it to use 4x li-ions for 4 crees?



You don't need more Li-Ions to run more diodes, just more boards in parallel. However it's not the best scenario.

The drawing shown is actually _two_ 1400mA boards in parallel, to give 2800mA to drive a P7. Each board has 4 * 7135 regulators. Each 7135 gives 350mA to give a total of 1440mA per board.

The Cree LEDs only need (actually) 1000mA to drive to max. Therefore the circuit as shown needs two crees in parallel to accept the current, even when the input voltage from the cells could overdrive one. However as shown it will still overdrive the 2 Crees. It would work OK with the hungry old K2 Lumileds.

For crees I would use 2* (3 * 7135) boards instead, to give the required 2000mA for two in parallel.

So the battery usage is to give the required voltage, not to drive more LEDs.

As Mr Happy said, running LEDs in parallel is risky unless they are very well matched. I would prefer to use a single 1000mA board, driving 3 LEDs in series, and have the same setup for any more LE chains. You can drive them all from the same battery pack.

Obviously more batteries in parallel will give a longer runtime.

If you are still confused let us know.

Nick


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## OldNick

Mr Happy said:


> I was just confirming. No dig intended



Naaah! None taken. I appreciate your explanations. Better too much than the usual snappy one-liners

Nick


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## download

OldNick, I updated diagrams are what I am using actually.
It does not mean AA not work. 
3x AA is very closed to 1x li-ion 18650 in many way.
It should work, if you match it like 3x AA = 1x Li-ion.
But I did not test it yet like 4x li-ion equal or not to 12x AA.

07accordEX, 2rd setup is: parallel 2 Cree in 1x Li-ion only 
They just share max current like 2.8A /2 = 1.4A per Cree.

4x li-ions for 4 crees = 1x (4x7135) driver connect 1x LED or P7 and serial 3x LED or P7 outside like diagram 1 driven by 4x Li-ion.

You guys type faster than me. :thumbsup:


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## OldNick

download said:


> OldNick, I updated diagrams are what I am using actually.
> It does not mean AA not work.
> 3x AA is very closed to 1x li-ion 18650 in many way.
> It should work, if you match it like 3x AA = 1x Li-ion.
> But I did not test it yet like 4x li-ion equal or not to 12x AA.
> 
> 07accordEX, 2rd setup is: parallel 2 Cree in 1x Li-ion only
> They just share max current like 2.8A /2 = 1.4A per Cree.
> 
> 4x li-ions for 4 crees = 1x (4x7135) driver connect 1x LED or P7 and serial 3x LED or P7 outside like diagram 1 driven by 4x Li-ion.
> 
> You guys type faster than me. :thumbsup:



Ok. Thanks for that. 

I may type faster but your post says it better. I misunderstood the question. As you say, you can add more cells in series, as long as you have a new LED for each 3.6-4 volts of battery pack.

Nick


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## OldNick

I have to stress again.

The Cree XRE will blow up at 1400mA. Use only 3*7135 board per LED in parallel.

In fact I would seriously look at a 700mA board. Far more efficient (1.4 times current gives 1.25 times the light). Less heat management. Longer LED life. Get another LED if you want more light, and drive that one at 700mA as well. (Use the single 1400mA circuit singly to drive 2 LEDs, _maybe_)

Nick


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## 07accordEX

hmm thanks for all the input 

with this set up the batteries would drain quicker right?


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## OldNick

07accordEX said:


> hmm thanks for all the input
> 
> with this set up the batteries would drain quicker right?



Sorry. Not being smart. Which setup?

There were two types offered. One was to add more LEDs and controller boards in parallel (mine) and the other to put more in series (Download's and more sensible). 

However as my excuse I did not understand what you were asking. <G>

If you put more LEDs and boards in parallel, using the same number of cells, then the battery will drain faster. 

If you put more LEDs in series, then you also have to add more cells in series; basically 3.7 V or so for every extra "layer" of LEDs. They will not drain faster, because they are putting out the same current as before. 

It's as if you had added more cells in parallel in "my" circuit (more LEDs in parallel) to give a "fatter" pack that has more energy stored.

Nick


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## 07accordEX

sorry i tihnk i am a bit confused but heres my goal (maybe this will help you help me lol): im building bike lights with 4 cree xre's and need a cheap driver, but the requirement is that the amp draw from the batteries is low (like around 1A)


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## OldNick

07accordEX said:


> sorry i tihnk i am a bit confused but heres my goal (maybe this will help you help me lol): im building bike lights with 4 cree xre's and need a cheap driver, but the requirement is that the amp draw from the batteries is low (like around 1A)



As do we all ...<G>. But before you get too carried away, have you _seen_ 3 Cree Q5s light up together? 3 on the bars and 3 on the head and you nearly have a car's high beam!

Why do want low current? I can see a few reasons (thinner wiring etc, which is why I like this circuit that download has shown) but in the end you only get so much runtime out of so many cells of a given size, using a given light output.

Ok. Use Cree LEDs (Q5) and a series circuit. Do exactly what download has described. If you want more LEDs then add another 3.6 -4 V cell set (3 * AAs or 1 * Li-Ion) for each extra LED.

Do _not_ use a 1400 mA board per led, as I said. You will blow the LEDs. Work on 700 mA per LED, with an extra LED for that extra brightness.

So. For Crees, here is my idea. Instead of the twin 1400mA boards shown (they are great for the much more powerful P7), use a _single_, 1000mA board 
- (you can get 700mA ones, but only in packs of 20. Excellent value at a dollar each, but unless you need a heap it's wasted $)
- If you want, you can use one of the multi-mode ones to save battery life and have levels of light for less critical situations. But for reliability, use the non-multi-mode drivers. I am not sure why, but the multis seem a bit. Flaky. Low currents etc.

AFAICS you _must_ use the 7135-based boards for this. Others have completely different modes of operation.

Using download's model as a basis, place 1 * Cree Q5 across the controller board. Then for each extra LED that you put in "underneath" as shown by download, you need another layer of cells, either Li-Ion or NiMH, to give you the needed 3.6-4 Volts each layer.

I will do a drawing if nobody beats me to it.

A word of warning. What's your electrical experience? Building stuff like this is not always "cheap". $10 components can disappear in micro-seconds. It is interesting however to try this stuff. But be prepared.


For $20 and some in the US you can get a BuckPuck. Fully regulated, and can handle a huge voltage range to run several Q5s in series. No muss no fuss. Fully adjustable brightness by a single variable resistor.

Nick


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## OldNick

OK. As Mr Happy did, I did some calcs of worst case either end. (stubborn SOB like me needs it in my own words!)

It seems to me that the limitation of this idea is that although the driver circuit can handle a range of voltages, the more "free" LEDs you add, the more easy it is to fall outside that range, given that LEDs change Vf and cells change Vout over their discharge run.

I did the maths for 3 "free" LEDs and one "Driven" one and it increasingly limits the acceptable battery VOut and LED Vf, the more "Free" LEDs you add, AFAICS.

In fact I did not even go to 1 Volt out each from the cells because 1.2 was already unacceptable, in that failure modes outnumbered success modes if the Vfs of the LEDs were high.

There is one weird thing. Cree's own data shows a Min Typ and Max Vf for the XREs, except at 1000mA. I am not sure what this means, because AFAIK the Vf is a function of the individual LED and not the current through it. In fact there _is_ no current until Vf is reached! <G>

If the Vf is indeed more reliable at 1000mA/3.7 V that still seems to be a problem at 1.2V/cell.

At 1.2/cell Volts VIn = 14.4 Volts
3 * 3.9 Vf = 11.7 V which leaves 2.7 V no good
3 * 3.7 Vf = 11.1 V leaving 3.3 Volts no good
3 * 3.5 Vf = 10.5 V = 3.9 V OK.

"Beam" (ark ark) me up, Scotty on this one? I suppose it _could_ mean that you must not exceed 3.7V to the LED if you are driving it at 1000mA ????

Nick


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## Mr Happy

OldNick said:


> In fact there _is_ no current until Vf is reached!


In fact, this is not quite true, as Vf is not a threshold, it is a range. For any given LED sample, there is a graph of Vf and current as shown in this chart that I grabbed from the Cree XRE data sheet:







So with a forward voltage as low as 2.5 there will still be some light output. There is a gradual and graceful decline in light output as the voltage drops, which allows much more freedom for the circuit to continue working as the batteries run down. If course if you want to ensure plenty of light you need to provide more voltage for the 7135 regulator to work with. With NiMH this is easy, you just add a few more cells to the battery.


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## OldNick

Yeah I saw that afterward in the PDF (brain f&*t), but it was late and I was tired. I was going to correct myself this morning.

It was just strange that there is no Min Typ Max for 1000mA. It is just 3.7 V. I can understand it being a Max of 1000mA (theoretical failure point beyond that) but some would have lower values.

Anyway, as I said even at a steady 3.7 V the circuit seems limited if you go higher than the two layers of "free" LEDs.

As you said before, the trouble with this circuit is that it will not fully utilise the cells' capacity, in that you can quite healthily discharge an NiMh below 1.1 Volts (I have been told by my charger people). With a straight 1-controller setup, you can add an extra cell layer or so so that you stay within the parameters of the board and maximise the runtime of the LEDs.

I am not up with the behaviour of these boards enough to know, but could you use any of the buck-boots boards that DX has to improve this? Or are their characteristics not suitable? I do know that one I saw some figures for was very inefficient and hot right at the transition from buck to boost, so you may have trouble there.

But would they manage the volts and current in a way that allowed them to be used?

Nick


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## mdocod

very clever idea. !! nice work!

Eric


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## Mr Happy

What I think will happen in practice is that everything will adjust until it balances.

From what I can tell of the 7135 regulator, it will limit the current if it tries to exceed the maximum, but it will drop out of the circuit otherwise. From reading the data sheet I'm not sure what voltage drop it imposes, but it seems to be quite low.

So suppose we take your example of 1.2 V/cell Vin = 14.4 V:

What happens is that for four equal LEDs, the voltage will divide equally between them. Each LED will see 14.4/4 = 3.6 V.

Assuming the chart I posted to apply, that will give a current of about 750 mA.

If this is less than the set point of the regulator (assume 3 x 350 = 1050 mA), then the regulator will drop out and you will get 750 mA of brightness from the LEDs.

Likewise, 12 x 1.1 V = 13.2 V. 13.2 V / 4 = 3.3 V. LED current = 300 mA (approx).

Now, with fully charged cells, 12 x 1.4 V = 16.8 V. 16.8 V / 4 = 4.2 V. LED current = off the scale. At this point, the regulator will cut in and limit the current to 1050 mA. Hence the voltage seen at the input to the regulator will be 16.8 - 3 x 3.7 = 5.7 V (assuming my posted chart to hold). Since 5.7 V is within the range of the 7135 max input voltage, everything is good.

In short: you could use 4 x Cree XRE, with 3 external and one internal to the regulator, driven by 12 NiMH cells, with 3 x 7135 for 1050 mA, and it should be good.


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## download

07accordEX, 

This setup is limited by close voltage difference between battery & LED.
1x LED to *1x Li-ion *or *3x AA Ni-MH*.
2x LED to *2x Li-ion *or *6x AA Ni-MH*.
3x LED to *3x Li-ion *or *9x AA Ni-MH*.

I would recommend 4x LED to 4x protected 18650 li-ion.
Drive with 3x 7135 with multi-level.
Fully charged protected 18650 mostly ~4.1V.

OldNick & Mr Happy, Thanks for your input.


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## OldNick

I am concerned that although 5.7 V is within the range, that assumes that the LEDs are indeed at 3.7V Vf, and I am still surprised if there is no variation. There is very little room for error. 3.6 or less and you are right there.

Just OOI, what does happen to a 7135 if it gets more than 6V?

I think my problem was that I forgot that as soon as you load a NiMH, it will not have 1.4 Volts even when fully charged. That is the headroom that allows you to add that extra layer of cells, so that you still get good drive at 1.2V per layer. I was being cautious and only using the lesser layers.

In fact, in line with my thinking that 700mA is better than 1050 for several reasons, just 2 7135s per system would work. That would apply until the voltage dropped to 1.2 V /cell and if as you say the regulator then drops out, you would not see any change from fully charged, right across the "shelf" discharge time of the cells.

Nick


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## OldNick

download said:


> 07accordEX,
> 
> This setup is limited by close voltage difference between battery & LED.
> 1x LED to *1x Li-ion *or *3x AA Ni-MH*.
> 2x LED to *2x Li-ion *or *6x AA Ni-MH*.
> 3x LED to *3x Li-ion *or *9x AA Ni-MH*.
> 
> I would recommend 4x LED to 4x protected 18650 li-ion.
> Drive with 3x 7135 with multi-level.
> Fully charged protected 18650 mostly ~4.1V.
> 
> OldNick & Mr Happy, Thanks for your input.



Heh! We haven't finished yet! <G>

This has been great. It has made me remember a bit of stuff, think, and brought me up to speed on the regulators and how they interact.

If Li_Ions are 4.1 each than that is quite safe. Great. Is that non-loaded? Do they, like NiMHs, drop away from that as soon as you load them?

Nick


----------



## download

*Re: Poorman MultiLux setup method*

OldNick, 
This 7135 driver sure have some limitation, like it can't provide constant current when battery voltage drop out ....... 
It is relativity cheap & efficient if battery match LED. And  like me.

When feed more than 6V in 7135 per LED, driver will heat up very fast, dim and flash. May die too. 

For li-ion, I'm not expert, SilverFox is the one. check this out.
https://www.candlepowerforums.com/threads/117117


----------



## OldNick

Thanks download.

It's not a bad circuit for all of its limits. As you say the price is incredible, when it's already on a board. I was going to build myself a voltage regulator board (not current) and just live with slight inefficiency, by matching Cell volts to LED volts, but these boards make it not worth the trouble. The whole board costs less than it would cost me to just get the regulator IC.

As I said in a previous post, you will get a good, even runtime @ 700mA with these if you don't want max power to the LED. That suits me. With your idea, you just add one extra LED to make up the light, and more efficiently as well! :twothumbs

In fact, that is a point. If I missed its being said before then sorry. AFAICS this circuit increases efficiency enormously, because you have only one "resistor" (7135 board) in circuit. The rest are pure LEDs. If you drove each LED with a controller board, you would get ...what...~80% (average) (??) for each LED. This way the LEDs share the losses of only one board.

Interesting link. Thanks. But you have to watch the graph scaling, as was pointed out in the thread.

Nick


----------



## freedom2000

Wouha...

Very very clever idea :candle:

using one AMC7135 to regulate the current of one led and then add as much you need leds inseries sharing the same current --> great great idea :thumbsup:

And now... if you want to add modes to this serie of leds... what about adding a µ controller to control the VDD pin of the AMC chip with PWM (this works I know).
But will it work also for the rest of the serie (ie the leds not directly driven by the AMC board) ?
I would say yes... but I still need to think about it a bit more (not sure what will be the behaviour of the µcontroller as it must be powered by the voltage issued from the series of leds... (not to burn it with over voltage 7V max) ???


So you could get a flashlight with modes (low med high) composed of multi P7 leds... Very very bright idea :thumbsup:

JP


----------



## OldNick

As download has suggested, you use one of DX's multi-mode boards to get brightness control. All the LEDs share the current of the board, so it controls all LEDs in the string.

The P7 setup suggested actually uses two boards in parallel, one of them a multimode.

I believe the DX multimode boards have a programmable controller chip on them, so you could programme your own modes if you are up to it.

Nick


----------



## freedom2000

Mr Happy said:


> Now, with fully charged cells, 12 x 1.4 V = 16.8 V. 16.8 V / 4 = 4.2 V. LED current = off the scale. At this point, the regulator will cut in and limit the current to 1050 mA. Hence the voltage seen at the input to the regulator will be 16.8 - 3 x 3.7 = 5.7 V (assuming my posted chart to hold). Since 5.7 V is within the range of the 7135 max input voltage, everything is good.
> .



Nice demonstration... but I am afraid that we have neglected an important parameter.
The VF of a LED is not constant for a given current... Temperature is playing also a key factor  
and unfortunately when the temperature increases the Vf decreases. (see here §2.2)
So let's assume that Vf decreases down to 3.5V with fully charged cells you will get :
16.8 - 3*3.5 = 6.3V which is above the nominal 6V of the AMC7135 chip :thumbsdow

But does it ????

THe answer is probably NO .
Why ? 
1) the maximum voltage of the bat will not remain that high a long time...
2) the maximum voltage rating for AMC chip is not 6V but *7V*
if you don't trust me see here page 2 :twothumbs

Finally your idea is much safer as we could imagine despite the fact that several factors increase the difficulty... low led Vf, VF decreasing when temperature is climbing (very quickly when driven at high current (a matter of seconds...)), battery voltage being high when fully charged...

JP


----------



## freedom2000

OldNick said:


> As download has suggested, you use one of DX's multi-mode boards to get brightness control. All the LEDs share the current of the board, so it controls all LEDs in the string.
> 
> The P7 setup suggested actually uses two boards in parallel, one of them a multimode.
> 
> I believe the DX multimode boards have a programmable controller chip on them, so you could programme your own modes if you are up to it.
> 
> Nick



My only concern is that if you use 3 Liion then the voltage for the µ controller will be too high, and you must put the µcontroller into the serie of leds (as suggested above). 
The PWM will thus only affect the "AMC driven" led.
When the PWM is "high" the AMC VDD pin will be on and the current will flow --> no problem
When the PWM is "off" the AMC VDD pin will be to 0 V and the current will not flow.
But the µcontroller will still be powered by the link Plus bat - µcontroller-LED-LED-negative bat.
I suppose that the current will be very very low (but not really zero as the µcontroller is powered).

So when seeing this curve :





we can see that with a "almost zero" current the Vf of the led is around 2V
This means that the drop out due to series of leds will not be 2*3.7 = 7,4V but only 4V. Which means that the µcontroller will be powered at 3*3.7 - 4 = 7.1V.... which is really high for this chip 

see page 85 absolute max VDD = 6.5V.


And this could be worse with fully charged cells 3*4.2V - 4V = 8.6V...

Am i wrong or not to be afraid to fry the µcontroller ?

JP


----------



## OldNick

JP

I appreciate your input, because it opens up a new possible problem. The circuit that "download" has proposed is wacky and yet it works. So it deserves questioning to the NTH.

However, download has used the circuit he has described, with 3 * Li-Ion cells, and it has worked fine. 

I am not aware of the reason for this. (hey....apart from your objections..... if the single controller board cuts off the supply to the "free" LEDs, then what powers the PCU (mu controller) which makes the 7135 keep working ????) 

Nick


----------



## freedom2000

OldNick said:


> JP
> 
> I appreciate your input, because it opens up a new possible problem. The circuit that "download" has proposed is wacky and yet it works. So it deserves questioning to the NTH.
> 
> However, download has used the circuit he has described, with 3 * Li-Ion cells, and it has worked fine.
> 
> I am not aware of the reason for this. (hey....apart from your objections..... if the single controller board cuts off the supply to the "free" LEDs, then what powers the PCU (mu controller) which makes the 7135 keep working ????)
> 
> Nick


Hi again,

BTW if you carefully look at the schematics provided by "download" you will see that he mentions 8 AMC7135 driver. So if there are 8 AMC chips this means that threre is NO µcontroller... On the contrary it would have been 7 AMC7135 (3 on one board + MU and 4 on the other board)

On the other hand I have ot said that the free leds where "cut off" but more possibly that they are connected to a high impedance of the µcontroller so that the current drawing into the free leds exists but is very very low (and the leds are completely dim). And this is my concern, when the current in the led is near zero then the Vf of this led is close to 2V...

I have the AMC7135 board + µcontroller 1050 mA version but I am now lacking of two leds to test this "in real life" with a 2*Liion configuration 

If you have the material to test (2 cree, 1 driver, 2 liions) , please just do it with 2 Liion half charged and measure the voltage on the µcontroller (between + and - of the driver) at low, med high and long flash off

Thanks 
JP


----------



## OldNick

I can't test it, because I don't have strings of matched LEDs. I have lots of LEDs, but they are all different! <G> They are on order, but from DX, and that means weeks! <G>

This needs confirmation, but download said in a later post that his circuit was exactly as 
https://www.candlepowerforums.com/threads/195358

which does have one 4 * 7135 and one 3 * 7135 board, with the 4* board slaved to the controller of the the 3* board.

Nick


----------



## download

I would like to suggest to wire it. See it.
No need to guess.
Simple & cheap experiment after all.


----------



## Mr Happy

Forgive me if I am stating the obvious, but LED's don't have to be matched when connecting in series except that they all need to be rated for the same current. They can be different Vf's, different manufacturers even.

Choose whichever LED has the lowest design current and regulate the current based on that one.


----------



## OldNick

hmmm. I agree. But I have reservations

I have K2s and crees and SS LEDs. They may vary quite a bit in Vf and behaviour. Normally this would not matter, but with this particular circuit, I am concerned about running too close to the bone.

However I have realised that I have some K2s that I bought. I may try those.


----------



## freedom2000

download said:


> I would like to suggest to wire it. See it.
> No need to guess.
> Simple & cheap experiment after all.



Hi "download",

Could you please confirm if you have used :

- two of these 4*AMC boards :





or

- one 3 AMC+modes + one 4 AMC :





Thanks

JP


----------



## download

Both setting I tested & used, work smoothy in mine.
If you want lower current, Just use 1x (4x7135) or 1x (3x7135+modes).
Use more 7135 just draw more current to drive LED when battery full.
After battery drop out, brightness is not much different between how many 7135. 

You should most concern the driver can stand or not when *Battery FULL* rather than anything.
The multi-mode work smoothy even battery went dead.


----------



## OldNick

EDIT: Please see later posts. As shown, the circuit will have trouble handling 3 "free" LEDs when battery is fully charged. There is a solution offered by "download".

I just wanted to provide an alternative view of the circuit, in more traditional form.

Here is the link. 
http://www.4shared.com/file/55484690/baeefacd/SNAG-0001_16-07-2008_44906_PM.html


the password is " nicksaidso "

The circuit is for 1000mA, for such LEDs as the Cree Q5.

Hope this helps somebody.

Nick


----------



## download

Re-post for you. :thumbsup:


----------



## OldNick

Thanks for that, download. I will try that photo site again. It's handy for just this.
Nick


----------



## freedom2000

download said:


> Both setting I tested & used, work smoothy in mine.
> If you want lower current, Just use 1x (4x7135) or 1x (3x7135+modes).
> Use more 7135 just draw more current to drive LED when battery full.
> After battery drop out, brightness is not much different between how many 7135.
> 
> You should most concern the driver can stand or not when *Battery FULL* rather than anything.
> The multi-mode work smoothy even battery went dead.



Thanks download, it clear for me now :twothumbs

JP


----------



## OldNick

download you are a freakin genius!

I plucked up the courage to give it a go this morning. (It's not the money, but I only have 2 of these boards and waiting for the next lot from DX takes forever).

Apart from the fact that I was using "raw" LEDs without focusing and now I can't see my keyboard to type properly, and that I nearly had an epileptic fit from the "police strobe" mode <G> I am rapt. 

I guess you say this idea was "brilliant" (ark ark) 

I used a 7.2V pack, with 2 K2s, and got 1100mA at max power.

There is one strange thing. At one low setting the "free" LED glows very dimly, whereas the "controlled" LED does not. I am going to see what mode it is and what voltages are. I will also swap LEDs around and see if that changes things.


Nick


----------



## OldNick

I think freedom2000 may be correct in his idea about the volts across the controller board when the unit is running, but in "off" mode. 

The LED that shows very dimly is during pauses in the SOS mode. At that time, there is about 0.9V across the "controlled" LED and 2.6V across the "free" LED, which just glows very dimly. But the board is carrying the rest. My cells are very freshly charged, at around 7.9V, so the board is carrying 5.3V

I realise that the board's absolute Max is 7V, so it's still OK, but it was a valid point, and needs remembering.


The board survives and what gets me is that is does not get even warm when left running on 1100mA. If kept so just that little bit extra volts are there, it is really rather a nice setup.

And 91% efficient at fully charged.

Nick


----------



## OldNick

Ok. Here's the latest.

Firstly my apologies. My circuit shows Zener diodes, not LEDs. Rusty old me.

First the bad news.

This is with K2s.

I tried the circuit with 4 LEDs and 12 cells, fully charged.

1.48 * 12 = 17.8 volts. And the battery _can_ maintain this voltage under load, if you use sub-Cs as I am.

On the lowest setting of a controlled board, the current was about 80mA and the voltage across the board was about 8.2 volts. I think the Vf of the diode on the board probably dropped it just enough.

In the SOS mode, the SOS runs just once, then stops. This is because with the current stopped by the controller circuit, the voltage across the board is VERY high. 
17.8 - (2.6 * 3) = 9.96 V. I am calculating here, but I measured these.

The good news. The clever little devil shuts itself down rather than blowing up. Having not blown it up thus far I repeated the effort, and AFAICS it will shut itself down. Also because it's not supplying more than a tiny amount of current it does not get hot.

So the bottom line is that you *can* run 4 LEDs, with 3 uncontrolled, but only if you prevent the current, _while the controller has control_ (high battery volts) from dropping below a point at which the Vf of the "uncontrolled" LEDs is small enough to leave more than the board can handle. 

This will of course depend on the LEDs. It also depends on the battery voltage at any given time.

At the same time, running two "uncontrolled" LEDs with 9 cells can also cause trouble at full charge, again if you drop to the low setting of the controller board.

1.48 * 9 = 13.32.
13.32 - (2.6 * 2) = 8.12. Again stretching the board.

Nick


----------



## mikemo

Not sure if I missed something simple, but won't the current through the regulator board be different from the current of the led it is driving? If so, then the "free" leds will have a different current (higher) than the driven led.

Just curious. Looks like a clever idea.
Mikemo


----------



## download

OldNick, 

Good finding!
I'm using li-ion x3 only, I think the freshly charge 4.1V is closer to Cree Vf.
The bad effect of controller is not obvious. 

For 1.48 * 12 = 17.8 volts to 4 LED, compare li-ion 4.1 *4= 16.4V 
I would suggest use more than one 7135 board in serial to share excess voltage. 
like (3x 7135 multi-mode to LED) serial (3-4x 7315 to LED) serial (3-4x 7315 to LED) serial (3-4x 7315 to LED) ............. over kill :sick2:
Or (3x 7135 multi-mode to LED) serial (3-4x 7315 to LED) serial ( free 2x LED) is already enough...

Still a poorman setup method. 

mikemo, no different in nake eyes.


----------



## OldNick

Good idea. I was not sure if you could place them in series. Use one controlled one, and one cheap full-power one. Great idea, and as you say still cheap. With NiMH, because of the charge-discharge voltage range, the limit seems to be 2 "free" LEDs, unless you are happy to have only full power and the one down from that. I really have no use for the strobe or SOS bits anyway. I suppose it might be useful to scare motorists when I am riding! Nick


----------



## OldNick

mikemo said:


> Not sure if I missed something simple, but won't the current through the regulator board be different from the current of the led it is driving? If so, then the "free" leds will have a different current (higher) than the driven led.
> 
> Just curious. Looks like a clever idea.
> Mikemo



I have blown my Ammeter (they seemed to think that a PC board track could take 10A. The track blew before the fuse! BAH! ). But I take your point. So I used my new toy: a lightmeter The Lux readings were identical (within 0.5%) for both LEDs. I will rewire my ammeter and see about currents. , because I am seeing quite a wide variation in Vf between the two LEDs I am using (old K2s). This is because of the LEDs. When I swapped the controller from one LED to the other they retained their VFs. So it is not the controller itself. Nick


----------



## OldNick

mikemo said:


> Not sure if I missed something simple, but won't the current through the regulator board be different from the current of the led it is driving? If so, then the "free" leds will have a different current (higher) than the driven led.
> 
> Just curious. Looks like a clever idea.
> Mikemo



OK. Meter's up and running again.

I am pretty sure that the LED and the output share exactly the same current. This is what makes this circuit possible.

Anyway, the LEDs have exactly the same current, "free" and controlled.

I have not had this much fun in ages, electronically speaking. <G> Thanks download. Even repairing my DMM was interesting.

Nick


----------



## OldNick

download

Do you mind if I post a link to this thread on the MTBR forums? Or you can, whatever, if you are happy wioth that idea. There are quite a few guys over there doing DIY, and this should create some interest.

And sorry. Can you either confirm or test that two circuits in series definitely works. I have two to try, but both are multi-mode, and when you are testing a jerry rig, it's almost impossible to get them to both be in the same state (they have completely different mode patterns) <G>

Nick


----------



## download

Hi Nick,

Sure, it is just a small found only, and it is great to share some info to all good guys around here & there.

I am sure two circuits in series definitely works.
Because I did this at first,
(3x 7135 multi-mode to LED) serial (4x 7315 to LED) serial (4x 7315 to LED)
Max. current to all LED is 3x 7135 only.

And left only one multi-mode later.
(3x 7135 multi-mode to LED) serial ( free 2x LED)

Cheers!


----------



## OldNick

OK. Thanks. I will pass it on.

Thanks for the confirmation. 

Now I just have to wait for DX's endless delivery times. :-< 

Nick


----------



## download

FLuPIC is similar board (Not Max 6V, Max 3x Ni-MH, or 1x Li-ion per LED), it should work with better UI. :thumbsup:


----------



## OldNick

download said:


> FLuPIC is similar board (Not Max 6V, Max 3x Ni-MH, or 1x Li-ion per LED), it should work with better UI. :thumbsup:



Yeah but what happened to "poor man's"? 

Nick


----------



## phantom23

I'm just wondering... Is it possible to drive 3x P7 from 2xLi-Ion in series (8,4V)?


----------



## download

For 2x Li-ion, 2(serial) or 4(serial+parallel) LEDs will be easier.

8.4v can't drive 3 led in serial. Vin is not high enough.


----------



## OldNick

phantom23 said:


> I'm just wondering... Is it possible to drive 3x P7 from 2xLi-Ion in series (8,4V)?



No. 8.4 / 3 = 2.8V per LED. At this voltage, the leds will be very dim (somewhere around 100mA, where full power is at 1000mA). A chart of current vs voltage gas been posted earlier in the thread, actually, by MrHappy I think.

This circuit is not a boost circuit. It simply stops the voltage/current to the LEDs going too high when the batteries are fully charged.

Ah....As download has said, 1 cell per LED is the rule without a boost circuit.

Nick


----------



## phantom23

Is there any 'poor mans' circiut that can do it?


----------



## phantom23

Is there any?


----------



## Mr Happy

No.



> Ah....As download has said, 1 cell per LED is the rule without a boost circuit.


----------



## phantom23

I said circuit - boost circiut.


----------



## Mr Happy

Right. You need a boost circuit. There is no such thing as boost circuit that works like the subject of this thread. The method only works with linear current-regulating drivers.


----------



## download

phantom23,

No cheap multi-level boost circiut yet.

If price is not matter, there are some good driver like, Fatman, maxFlex, 
check this out:
http://www.taskled.com/


----------



## Mr Happy

Since it is normal to drive LEDs in series, a single boost driver can be used to drive 3 LEDs off one board of the right kind. It is a matter of finding a suitable board to match the available supply voltage and the desired number of LEDs and drive current.


----------



## OldNick

phantom23 said:


> I said circuit - boost circiut.



Hey! Chill out man! 

I don't think you did mention boost. The replies were based on your posts. These guys are trying to help.

Nick


----------



## Mettee

Ok you guys....I have been reading up on this thread. I have read it several times so far and I am really interested. I am a rooky at this stuff and I am doing a single P7 in a 3D mag and now I want to do more. So I am thinking 3 P7's with three 18650's in a 2D mag (if I can get them to fit). The driver and multi mode or dimmer is where I am confused. I wired my single P7 light just like Stephan and netkids diagram but to get 3a. So from what I understand or guess , I need a 3x7135 regulated circuit and say a http://www.dealextreme.com/details.dx/sku.7612 wired as normal? Then wire as per Downloads diagram? 

Thanks for any input

Drew


----------



## download

Just combine driver like NetKidz 






And wire the driver like this will be fine. 





Welcome to the modding world.


----------



## mudman cj

The only problem now is that you can't fit 3 18650 cells in a 2D mag. 3 AW C cells ought to work though.


----------



## Mettee

download,

Thanks so much, I am glad to have the help!

Mudman,

I got my wire I ordered, thanks. And you are right about the cells, I was thinking about just using a 3D mag. I was hoping to keep it small. maybe I will rack my brain and try and figure out how to do the 3x 18650's in the 2D. I wish fivemega would make a holder for the 18650's so that they would fit in a tri-bored mag. Thats all the fun though, trying to figure it out 

Download can we see one of your lights by any chance? _EDIT nevermind, I saw them in another thread _

thanks,

Drew


----------



## mudman cj

You can't do three 18mm cells across in a D-sized mag even if it is tri-bored. You can fit two across with quad boring though. For a compact alternative, you could also use 9 Nimh cells, such as 2000mAh 4/5A sized cells in a tri-bored 3D body. These would give about the same capacity as 18650s.


----------



## Mettee

you guys are solid here, thanks for the help. Electronics are not my thing, I guess I will learn more as I go. I was hoping for less battery to worry about and have it not weigh as much.

What about D size litium ions? And of course I mean in a 3D

Drew


----------



## mudman cj

Deleted because I was way off base. I thought I was replying to an incandescent question.


----------



## download

Safety always is first priority. Only the protected Li-ion is suggested. 

From 18650 to C or D size li-ion. Voltage is same, just the capacity, size & price are different. Both can be used by this setup.


----------



## download

Just found my (3x7135 multi-level) & (4x7135) boards have a different 7135,
The (4x7135) that AMC7135 do *NOT* work with (3x7135 multi-level) controller IC.
If your board like this and wire them together, the mid & low mode will have no light come out. 






Below is the way to make it work fine like 3x7135 + 3x7135 = ~2A output


----------



## OldNick

Hah! Well found and well fixed download. When I read the reply in my email I read only the first couple of lines, and I was going to say that maybe it was the circuit/wiring rather than the actual chip.....but there you have gone and done it.


I have made little progress. I bought a new camera and have had no end of trouble trying to return it when I discovered that it was faulty. It has taken more than two weeks of fighting and stress. SO I am not in a "spend money on the Web" mood at present.

Nick


----------



## X_Marine

> Below is the way to make it work fine like 3x7135 + 3x7135 = ~2A output


That might save a few hrs for a lot of us.. ')
Thanks Download. :wave:

X/BillyD..


----------



## freedom2000

Thanks Download for sharing this info.

However I am a bit confused as I have already succeeded in pluging a µcontroler to two 4*AMC boards when modding my SSC P7






and evrything worked perfectly together...






the µcontroler was extracted from this dead driver 





JP


----------



## download

I think it is just mix & match.
I used this MCU wire with (4x7135) + (4x7135) work fine for me from beginning.
So I assume the (3x7135 multi-level) should work the same way too. But it didn't.
In my test, 8x7135 is the max. no for MCU could handle, like 12x that MCU will


----------



## Mettee

download and anybody else,

I am think of doing something not sure I can do. I want to do a triple osram ostar light. what bats would I need to run it, and what driver/s would "maybe" work?

I already have a heatsink design, and I may use an FM elaphan(8x18650's). My question is how do I figure out how much battery to use? 

Is it possible? I want to try it. I know I am nuts


----------



## download

Your highest grade modding parts should use top quality driver. 

Master bFlex control 2x Slave bFlex for each osram ostar.
http://www.taskled.com/bflex.html

SHARK Step up Converter Board 
http://theledguy.chainreactionweb.com/product_info.php?products_id=1136


----------



## Mettee

.


----------



## TorchBoy

*Re: Poor man multi-Lux setup method*



freedom2000 said:


> Wouha...
> 
> Very very clever idea :candle:
> 
> using one AMC7135 to regulate the current of one led and then add as much you need leds inseries sharing the same current --> great great idea :thumbsup:


Thank you. :wave: It's great to see it in use with the P7, and there are lots of imaginative variations on it in this thread. Great diagrams, too. :twothumbs

Edit:


download said:


> I found some interesting setup method to use the cheap driver board like 7135.





download said:


> *My* wiring way to use it as multi-led only.
> Use same driver to drive more than one LED.
> The driver control one LED only, the other LED just follow the current.
> Under one condition: 1x Li-ion or 3x NiMH to 1x LED.
> Simple & Cheap.


Cheaper than using three drivers each with their own LED, eh. :ironic: Anyway, nice diagrams.


----------



## download

TorchBoy :thumbsup:

Multi-level 7135 board works quite well with MagD switch, but not in MagC switch.
After choosing your mode you want, release the button will change to next mode that you don't want. 
Stretch the fatter spring inside the switch and Progold all contact may help a little.


----------



## freedom2000

*Re: Poor man multi-Lux setup method*



TorchBoy said:


> Thank you. :wave: It's great to see it in use with the P7,



Torchboy, It was (in december 2007 ) and it is still a great idea :thumbsup:

JP


----------



## TorchBoy

*Re: Poor man multi-Lux setup method*

I've finally read this thread fully. There are some very good posts, particularly regarding the effects of multi-mode controllers.



Bimmerboy said:


> that's a pretty damn cool discovery.





mdocod said:


> very clever idea. !!





mikemo said:


> Looks like a clever idea.


:kiss:



Bimmerboy said:


> I definitely vote for this as "killer find of the month", maybe the year!


Which year? 



download said:


> In the real world, when the battery voltage lower than LED, driver run as direct driver and LED will run lower Vf too.


If the Vf of the LED is under about 3.3 V you would also need to remove the polarity protection diodes for it to approximate direct drive (otherwise output current goes for a dive). You mentioned you did that, to gain more voltage. I don't actually think you needed to, since the P7 would be above that in any high current mode and there wouldn't be any lack of voltage in low modes, with the extra LEDs dropping fewer volts.



OldNick said:


> The LED that shows very dimly is during pauses in the SOS mode. At that time, there is about 0.9V across the "controlled" LED and 2.6V across the "free" LED, which just glows very dimly. But the board is carrying the rest. My cells are very freshly charged, at around 7.9V, so the board is carrying 5.3V


So the multi-mode chip by itself is drawing enough current through the extra LED to just make it light up even when the multi-mode chip has the "controlled" LED off. It's good to know the extra LED still drops a good 2.6 V in that situation.



mikemo said:


> Not sure if I missed something simple, but won't the current through the regulator board be different from the current of the led it is driving? If so, then the "free" leds will have a different current (higher) than the driven led.


Yes, by 200 microamps (200 µA, or 0.2 mA, or 0.0002 A) according to the spec sheet. As download said, it's not noticeable to the eye at all. Actually, the best of my multimeters doesn't even have enough digits to show a difference of 200 µA with a single AMC7135 being driven at a nominal 350 mA. (My meter would just cope if the output was less than 300 mA, or if I was measuring, say, five AMC7135s in parallel.)


----------



## wildstar87

FYI, I ran into the issue of the 1A Multi-mode board having a different set of 7135 chips than the 1.4A boards.

I happened to have one extra 1.4A board, and carefully removed the 7135 chips from it, and put them on the 1A Multi-mode board. It seems to work fine. I'm running multi-modes with two 1.4A boards and the 1A Multi-mode, for a total of 3.9A to a P7.

Haven't been running it that long, but it seems stable, and the modes don't seem to have any issues so far.


----------



## download

:wow: wildstar87, 3.9A to a P7 :goodjob:

What battery you use?


----------



## wildstar87

I'm using 4D Ni-MH Accupower LSD batts. They seem to be handling it just great. The head does get hot, but the LED hasn't color shifted, so I guess it's doing the job ok.


----------



## kevinm

Has anyone tried this with 2 RCR123's? I know that they are not supposed to be discharged beyond 2 times the capacity (1.4A or so), but it seems like the second of Download's methods might work with a Cree MC-E.


----------



## StefanFS

I used this idea from post#1:







I tweaked it a bit, the CREE Q5 WG are driven at 1.5A each. In a 2D Mag with a quad optic of very good quality and a multimode driver solution. Cell options are either 2 x D-size LiION or 6 x AA eneloop in a 6AA cell holder. I used user downloads heatsink, the 'multisink'. It works exceptionally well, I've been using it for two months now.


















I'm building another, now with 4 x CREE R2 WC and slightly less drive current, 1.2A each.

/Stefan


----------



## kevinm

That light looks great!:thumbsup: Is 1.5A safe for Cree Q5's?

Stefan, would you try 2 RCR123's in your setup for me and let me know if it will work? I'm deciding on parts for a build and need some info. It should be easy to just touch a wire to the battery negative and the wall of the flashlight. 

Thanks,
Kevin


----------



## download

:wow: StefanFS, I almost want to buy your beautiful light.
And your run-time graph is really something. :goodjob:

kevinm, Sure 2 RCR123's will work, it is same voltage of 18650, just shorter run-time only.


----------



## fordp

Will this work? Driver is a 3x7135. Driver The LED´s is Cree P4 
Will LED No. 1 and 2 shine as much as 3 and 4?


----------



## kevinm

download said:


> kevinm, Sure 2 RCR123's will work, it is same voltage of 18650, just shorter run-time only.



Thanks, Download. I know it should work in theory, but some RCR123's only have 500mAh of capacity. Running them at 1400mA is 2.8 times their capacity and I'm afraid that they can't push that much current. SO I wanted real world confirmation.


----------



## download

fordp, it should work, but 2 independent driver may work at different mode that you can't set them as same mode as you want if use one switch only.

kevinm, you got to see SilverFox post: :thumbsup:
https://www.candlepowerforums.com/threads/117117


----------



## kevinm

download said:


> fordp, it should work, but 2 independent driver may work at different mode that you can't set them as same mode as you want if use one switch only.
> 
> kevinm, you got to see SilverFox post: :thumbsup:
> https://www.candlepowerforums.com/threads/117117




Thanks, Download. I forgot that the RCR123 data was at the bottom of that thread!

Off to make something scary:devil:

Kevin


----------



## fordp

download said:


> fordp, it should work, but 2 independent driver may work at different mode that you can't set them as same mode as you want if use one switch only.



Thanks for the answer Download. I can see the problem that the drivers may come in different mode. Can there be any other way to connect 4 LED to 2x18650 and multi-mode? I know that the shark-remora works but it is far too expensive.


----------



## download

fordp, for 4 LED to 2x18650 and multi-mode

Here is the ~2A multi-level driver: 




Here is the whole wiring system:


----------



## Nanomiser

Looks like some beautiful work here guys! Very clever!

My current project needs a multi-P7 driver solution. I'm trying to figure out how to drive seven P7s in series, any ideas?

Also, where can I find some D-cell Li-ions?


----------



## jounihamalainen

Is it possible to drive two Cree MC-E leds with this configuration? If I'm correct I could use 7.4V li-ion battery and 8*7135 driver with two MC-E leds. I would connect one MC-E in parallel configuration between led+ and led- and other MC-E in parallel configuration to battery+ cable. With this configuration each die in MC-Es would get 700mA. Am I correct? :thinking:


----------



## download

Nanomiser, 7x P7 is huge project. Better driver should be used, like shark or CCHIPO from www.taskled.com.

jounihamalainen, 100% correct, just wire the Cree MC-E 4 lead parallel as one to driver, other MC-E wire outside. Similar below:


----------



## jounihamalainen

download said:


> Nanomiser, 7x P7 is huge project. Better driver should be used, like shark or CCHIPO from www.taskled.com.
> 
> jounihamalainen, 100% correct, just wire the Cree MC-E 4 lead parallel as one to driver, other MC-E wire outside. Similar below:



Thanks for your answer!

And it is also possible to use 4*7135 driver with the configuration in that picture above? One MCE and 4*7135 driver with 7.4V battery. The count of 7135 circuits is not related to battery voltage in any way? Only battery voltage and led voltage counts?


----------



## download

Basic concept of this setup:

1x LED to 7135 driver to 1x Li-ion battery.

If you want 1x MC-E to 4*7135 to 2x li-ion. This will be exactly the pic show 





Because MC-E have 4x led inside, you can wire like 
(Led parallel LED) serial (Led parallel LED), 
just the driver is 4*7135 instead of the pic show 8*7135, each Led have 700mA now.


----------



## jounihamalainen

Thanks, you confirmed my plans.


----------



## FluffyTapeworm

Very informative thread, thanks!

I'm thinking of building an MC-E light based on this idea. I'd like to do a multi-level light, but rather than use multi-level driver board I'd like a simple simple lo-off-hi switch.

I'm thinking with 2x 700ma amc7135 driver boards, I can use a DPDT switch to enable/disable one of the boards on the fly. This should give 350ma/die on low and 700ma/die on high, right?

Like this:






or maybe like this?





Still waiting for parts to come, so I can't test it myself yet.


----------



## gillestugan

first alternative will work great.
If you want more levels without multilevel board, you can use a switch that enables the amc7135 chips on the boards. In this way you can have 175mA, 350mA, 525mA or 700mA.


----------



## download

Like gillestugan said, the first one will be better to me.
It will be 350ma/die on low and 700ma/die on high. :thumbsup:


----------



## FluffyTapeworm

Thanks for the confirmations. Now if only DX would ship those drivers..


----------



## Nanomiser

Thanks for the suggestion download. I have already been dialoging with dat2zip, LEDZeppelin & Gryloc. Looks like I'm going with 3xBlue Sharks and an external pot.

:thumbsup:




download said:


> Nanomiser, 7x P7 is huge project. Better driver should be used, like shark or CCHIPO from www.taskled.com.
> 
> jounihamalainen, 100% correct, just wire the Cree MC-E 4 lead parallel as one to driver, other MC-E wire outside. Similar below:


----------



## javiole

FluffyTapeworm,

I have already tried the second diagram without the 2 slave diodes (great idea from Download). I used a clicky swicht from DX, 4$ for 5, with three positions, off,on1 and on2 and a zener diode between on1 and on2 (so both boards will work in on1 and only one board in on2). The advantage of the second diagram over the first one is that in the first one the switch, in the negative lead, will have to be able so resist 2.8Amps through, while in the second diagram the swicht is on the positive lead only feeding the boards and not the diodes. that means only few mAmps.


----------



## bbgobie

Thx download for the great idea. :twothumbs

I plan to use 1 MC-E with 2 dies before driver and two after.

For the driver, it should be ok if I use Netkidz multimode setup right? 1000ma Controller + 1 extra 7135 should mean about 700mA to each die. :shrug:
https://www.candlepowerforums.com/threads/192677


----------



## download

javiole, :thumbsup:

bbgobie, Yes, it is 100% correct.


----------



## bbgobie

Thx so much!
Already ordered!


----------



## caldina

Hi all,
I would like to ask for help, I had ordered AMC7135 driver, and I would like to use it to drive 4 X P7, Can any one help me to think about the suitable circuit diagram ?
I am really confuse about it and dont know how to handle it.

Please help ~~
[email protected]


----------



## bbgobie

If you wanna run them at full 2.8 amp you will need 8 AMC7135.
Run 3 in series b4 the driver and 1 connected to the driver normally.

Your battery would need 4 cells in series.


----------



## caldina

bbgobie said:


> If you wanna run them at full 2.8 amp you will need 8 AMC7135.
> Run 3 in series b4 the driver and 1 connected to the driver normally.
> 
> Your battery would need 4 cells in series.


 
Sorry,
I have no idea of 8 AMC7135, Do u mean I need 8 pieces of AMC7135 circuit board ?

Any powerfull circuit board can drive 4 x P7 with 2.8A ?
Please recommence. 
:mecry::mecry::mecry:I wish the AMC 7135 can do well ~~~
But i dont know how is the wiring ~~


----------



## trevlig

Hi folks,
thanks for an encouraging thread!

I've trying to get the most out of a MC-E for a bikelight.

Here's how I've wired everything.
First how I did before I saw this thread, and second how I've tried after reading all your info. (I've also ordered a multi mode controller, but I think I need to get a grip on theese things first)




My problem in the first setup is that even though I've wired everything for 2.8 A it only drains my batteries of ca 1.4 A (I don't have low voltage meter, so I've checked how much I need to charge the batteries after an hour of light).

In the second setup, which is the one I'm aiming at, I only got 3.01 V over each LED (die) and 6.5 V over the controller. The do get reeaaally hot in those cases. My Fluke told me I used over 350 mA (that's the meter's limit).
I've checked the controller so that both AMC are connected.

Here's the end of my LED knowledge. Can anyone give me a hint on where to look for the error?

tia


----------



## download

Welcome to the crazy modding world. :laughing:

caldina, 
P7 x4 is not cheap. If price is not matter, a better driver should be used. Like shark or CCHIPO/hipCC from www.taskled.com.

Actually, I don't think it will have a good result.
The AMC board will heat up very quickly and start thermal protection. 
Heatsink should be applied to the driver.







trevlig, 
Both of your diagrams look good to me.
The MC-E Voltage In is quite low.
In the first one. 
When your battery is full, it will draw 2.8A.
But the battery is near dry, normally it will lower current out ~1.4A

In the second setup,
The AMC board tranform the extra voltage to heat. 
When the Input voltage is higher the LED need, heat will be generated.
Suggect to heatsink the AMC board.

Or Use 7135 x4 (Each LED ~700mA) and wire like 2P2S below, the difference of Battery Vout to LED Vin become less. Less heat generate too.


----------



## caldina

Thank you Download,

If i changed to the driver your mentioned, how about the wiring ?
same as ACM7135 ? still need a heat sink about it ?


----------



## caldina

I wish to bulid a 4 X P7 headlight for bike and may be need to be run for 4 hrs in full power, i am worry about the geat geb and the wiring 
dont know how to solve ~


----------



## trevlig

download said:


> Welcome to the crazy modding world. :laughing:



Thanks!



download said:


> trevlig,
> Both of your diagrams look good to me.
> The MC-E Voltage In is quite low.
> In the first one.
> When your battery is full, it will draw 2.8A.
> But the battery is near dry, normally it will lower current out ~1.4A



The batteries were fully charged (+4V, 4 x 18650 cells). They ought to give more than 2.8 A. 

What I don't get is that I'm unable to get more than 3.2 V over any LED. Not even if I connect a single die to a 700 mAh 7135 controller :huh:



download said:


> In the second setup,
> The AMC board tranform the extra voltage to heat.
> When the Input voltage is higher the LED need, heat will be generated.
> Suggect to heatsink the AMC board.



The transforming of heat I already understood. Some energy will be lost as heat. Heat sink is not a good option. I will have enough problems cooling stuff down when I get it to work.




download said:


> Or Use 7135 x4 (Each LED ~700mA) and wire like 2P2S below, the difference of Battery Vout to LED Vin become less. Less heat generate too.



Maybe I should try that for my dual light. Both MC-E in parallel, one connected to a 7135 x8 and the other in serie with the batteries.


Two things I really didn't get testing things out yesterday:
What is the relationship between the LED's V and A demand. Is one more dominant than the other? (if anyone understands my question.

In my serial setup, I missed connecting the single die to the controller. Nonetheless the other three dies lit up only with the same characteristics as before (+3.0 V). Wasn't it the current through the regulated die that would drive the other dies?

tia


----------



## caldina

I had ordered SSC P7 from Kai Domain,
Is waiting ~~
Lets confirm with the wiring and driver first ~~
Cheers


----------



## download

trevlig,
See some of 7135 x4 board like this, you have to close the D2 point to get 1.4A, otherwise, 0.7A only.







caldina,
Please see the spec link below: 
http://www.taskled.com/techhipcc.html

Hope it helps!


----------



## trevlig

download said:


> trevlig,
> See some of 7135 x4 board like this, you have to close the D2 point to get 1.4A, otherwise, 0.7A only.
> 
> 
> 
> 
> 
> 
> Hope it helps!



I have the newer version of the board where the D2 is closed. (I actually bought a 20-pack of 700mA and re-soldered them to be 1400mA).
I've measured every pin on every 7135 to see that they all have contact.

I've moved to this setup, but haven't got any more amps... could anyone verify that I've soldered the 7135 on the right places? (My multi-mode is hopefully on its way, but I need to get a grip on this before).


----------



## download

Please check NetKidz & StefanFS posts, or take some pics of your driver to review it. 

https://www.candlepowerforums.com/threads/192677

https://www.candlepowerforums.com/threads/195358


----------



## trevlig

download said:


> Please check NetKidz & StefanFS posts, or take some pics of your driver to review it.
> 
> https://www.candlepowerforums.com/threads/192677
> 
> https://www.candlepowerforums.com/threads/195358



I've read them, and done it like NetKidz:





The only difference is that I've connected them back to back (and joined + and - by soldering a copper wire through the holes.


What I'm wondering is if I should do it like this with my two 1400mA:






I'll post some pics with my setup later.


----------



## axile

hi download in your 4 p7 driven with 1 8x7135 setup you say will need heatsinking the driver. is it posisble to split the voltage with 3 8x7135 for a different application?

http://img401.imageshack.us/img401/1788/foglighttest.jpg

if i have the circuit like this. is the 8x7135s be able to divide the voltage between the 3 of them and also i can add more leds as i see fit?


----------



## download

:welcome: axile,

Your concept is 100% OK! :thumbsup:
It should works better compare to mine. 
3 separated 8x7135 will divide the voltage & heat to each board.

Actually I tested the similar setup at car dome light before.
But the idling is not very stable at my oldie. Freaker did happen sometimes.

Hope it helps!


----------



## axile

download said:


> :welcome: axile,
> 
> Your concept is 100% OK! :thumbsup:
> It should works better compare to mine.
> 3 separated 8x7135 will divide the voltage & heat to each board.
> 
> Actually I tested the similar setup at car dome light before.
> But the idling is not very stable at my oldie. Freaker did happen sometimes.
> 
> Hope it helps!



thanks for putting my mind at ease haha


----------



## trevlig

I finally managed to get my setup (https://www.candlepowerforums.com/posts/2797871&postcount=144) to work. Must have been a bad soldering somewhere. Shame on me.

One thing that surprised me was that I actually had a Vmax of 3.3 V on my MC-E. This makes my setup on the edge of getting to hot when the batteries are fully charged.

On my next setup I will go the axile way


----------



## axile

actully i have another question lol. putting them in series like that wont make their current add together? since 1 of them will drive both input and output current at 2.8A.


----------



## download

In serial setting, each driver limit it max 2.8A current, so it won't be over 2.8A at each led.
If the voltage is high enough, led will draw 2.8A constantly.

14V input => 1x (8x7135) + 3x 3.7V
1x Driver loading = (14V-11.11V) x 2.8A = 8.12W heat

14V input => 3x (8x7135) + 3x 3.7V
Each 1x Driver loading = (14V-11.11V) x 2.8A / 3 = 2.7W heat

So 3x driver share the heat, at the same time, it will cost 3x too. :green:


----------



## axile

download said:


> In serial setting, each driver limit it max 2.8A current, so it won't be over 2.8A at each led.
> If the voltage is high enough, led will draw 2.8A constantly.
> 
> 14V input => 1x (8x7135) + 3x 3.7V
> 1x Driver loading = (14V-11.11V) x 2.8A = 8.12W heat
> 
> 14V input => 3x (8x7135) + 3x 3.7V
> Each 1x Driver loading = (14V-11.11V) x 2.8A / 3 = 2.7W heat
> 
> So 3x driver share the heat, at the same time, it will cost 3x too. :green:



cool but price of pcb is minimal compared to a p7 XD.

would you happen to know the maximum output voltage of the 8x7135 from KD im guessing if i wana run 4led/1 8x7135 it have to raise its output voltage to 14.8v to keep 2.8a flowing?


----------



## download

I think 3x P7, 12V is good enough, 14.4V may cost extra heat only.

1 8x7135 driver for 1 P7 need 4V, 3x 8x7135 driver for 3x P7 need 12V.
Wire should be like that.
If you want 4x P7, 16V is needed.


----------



## axile

sorry my picture is so bad lol. the 4 circle with + - was meant to be 4 p7 so total 12 p7


----------



## download

axile, you should make it like that.
But I really doubt it is a smart way.


----------



## axile

i guess with that set up we know the drivers would be nice a chilly :twothumbs


----------



## worldedit

I tried this setup with a 1x7135 river and 3 cree Q5 with a 3 cell lipo battery. It worked ok for 5 minutes. Now the led that is connected directly to the driver is off, the other two are lighting up very dimm. Did i fry the driver and why? Maybe the lipo battery doesnt drop enough voltage and the 7135 is getting to hot?


----------



## download

worldedit, 

7135 have thermal protection, it will shut down when overheat.
When it is cool down, it will work again. 
Did it turn on later when the driver is cool down?

You can turn on for 5mins, that mean you wiring is correct.
Try use 1x battery to 1x driver to 1x Q5. 
Test the driver is still OK or not.

What is the voltage of your 3 cell lipo battery?


----------



## worldedit

It didnt work again after cooldown. I just threw it away and used a resistor. the LEDs are ok. Maybe it was bad soldering after all.


----------



## krutzbeuazen

great idea, exactly what i need! want to power a handful of those cheap 1w leds for fixed illumination (had those leds left). had some 7135 boards left from some lights. got me a 15v converter from fleamarket. soldered it all together, easy thing:
3 leds in series connected between a single am7135 and the powersupply. one led connected to the 7135's out. that setup two times. powered it up, and, nice & bright. surprisingly bright and cool color, for those 1w leds.. *scratches head*
and while thinking this, the first leds begin to dim. begin to glow very dim, but blue. begin to glow brownish. the first led explodes. the second setup (in parallel to the first, now dead string) shines normally. a bit later, the first led of this string goes dim, a dark spot forms in the phosphor.

ok, i admit it, i turned it off immediately, and plugged it in again, to see what will ultimatively happen.. the leds were damaged anyway.

so.. all three "voltage dropping" leds died almost instantly. one from the other string died. the led connected to the output survived, in each setup.

never had a led explode, before.. i guess the transformer either has much more than 15v, or i connected the 1735 wrong. will check the voltage of the transformer now..

manuel


----------



## krutzbeuazen

i checked the trafo: 60v with no load, 11v when connected to a halogen bulb.
..i better watch out to short it before connecting anything.. ;-)

i checked the 7135 datacheet, connected everything again, here goes another led.

i then used another 7135 chip, bare, not connected to its board. works, drawn 220mA, stays stable, eventually (a minute) it starts flashing because of overheating.

hint: check the boards you use, even when you removed anything, there might be surprises left..
cost me 5 leds to find out.. i have exactly 12 left for three strings, better be careful now! 

manuel


----------



## download

krutzbeuazen,

Basic rule: 1x Li-ion or 3x NiMH to 1x LED.

7135 can't handle the voltage range excessively. (3-6V only)
Suggested to use 110/220V driver directly to your leds.


----------



## Changchung

I just finish my triple P7, I am really happy with it, I am using this driver;

http://www.kaidomain.com/ProductDetails.aspx?ProductId=1845

With the 2 Leds in serie technique









THANKS


----------



## lolzertank

Just a quick question...

The diagrams say the drivers are multi level. From what I know, the levels are implemented through PWM on the supply pin on the 7135 chips. Once the microcontroller turns the 7135s off, doesn't that drop the forward voltage of the LEDs to zero because there's almost no current (couple uA of leakage)? So let's say I used 2x fully charged Li-ion. Wouldn't the 8+ volts fry the AMC7135s (8 - 0 - 0 = 8 :shakehead)? 

I can think of three (crazy?) explanations.
1. The microcontroller draws a little current through the first LED, causing the vF to increase and protect the rest of the circuit.
2. The AMC7135's internal transistor can handle more than 7 volts, despite what the datasheet says about the maximum voltage on the OUT pin.
3. There's so little current it really doesn't matter.

Maybe I answered my own question. Still want a 2nd opinion though  before I burn something


----------



## download

lolzertank,

When the 7135 driver turn off 100% to the master LED (which connected to driver) It will be no light. 
But the 1x slave LED will get a few mA, so it will light up barely.

Battery 8.4V ---> (Driver will turn extra 1V to heat + Master LED 3.7V ) + ( Slave LED 3.7V )

Battery 12.6V ---> (Driver will turn extra 1.5V to heat + Master LED 3.7V ) + ( Slave LED 3.7V ) + ( Slave LED 3.7V )


----------



## lolzertank

I'm not sure you understand my question. Obviously, a LED driven at a couple microamps/nanoamps will have a forward voltage far less than 3.7. Basically I'm trying to figure out what happens when the LED's forward voltage drops when the AMC7135 switches off, mainly whether it'll destroy the AMC7135 chips if the forward voltage drops so much that the voltage across the regulator goes over 7v. 

Now that I think of it, I have this huge 10 pack of 1.4A boards ready to have traces cut, improperly used and possibly killed in the name of science... :devil: One chip less won't hurt, right?


----------



## download

3. There's so little current it really doesn't matter.

Just wire it, you will see how it works.


----------



## lolzertank

Thanks for the help! I'll try it!


----------



## jar3ds

so could we use this same idea with the taskled HipFlex? I want to run 5 P7's w/ 6xLiON's... since 6xLiONs=25.2v (the HipFlex has a max of 24v)... 

would running the battery right into 1 P7 to drop the total voltage down a Vf to ~21.7v, then put it that into the HipFlex and connect the remaining 4 in series just like normal? 

Thanks!


----------



## download

georges80
is the creator of HipFlex. :rock:
He sure have a better answer than me.


----------



## jar3ds

thanks download for your help.... this is what i got from george:


> 25.2V exceeds the max input spec of 25V. You could put a series diode into the VIN+ line to drop the voltage down 0.5V or so.
> 
> cheers,
> george.



so I'd assume I could do it with an LED instead of just a normal diode? If this would work, it would be the slickest setup...

Theres something telling me though "its too good to be true" with this... i sware I have to be missing something.... i feel like this setup breaks the laws of physics or something


----------



## download

George's driver is one of the best for flashlight mod. :rock:
You got the right choice. :thumbsup:


----------



## TorchBoy

jar3ds said:


> so I'd assume I could do it with an LED instead of just a normal diode? If this would work, it would be the slickest setup.


Yes, of course it would work, but you'd get a greater difference in current than the 200 µA difference in the AMC7135 setup. A quick calculation (assuming 90% efficiency) suggests it would be around 2,000 mA, because that's what the driver would draw to power four LEDs at 2,800 mA.

No laws of physics broken, just not the result you may have been looking for. Driving all five LEDs together (in series) would have them running on the same current.


----------



## The Dane

TorchBoy said:


> Yes, of course it would work, but you'd get a greater difference in current than the 200 µA difference in the AMC7135 setup. A quick calculation (assuming 90% efficiency) suggests it would be around 2,000 mA, because that's what the driver would draw to power four LEDs at 2,800 mA.
> 
> No laws of physics broken, just not the result you may have been looking for. Driving all five LEDs together (in series) would have them running on the same current.



Errrrr no!
If the board delivers 2800mA to it's LED's and have a loss of 10% then it uses 2800mA+280mA or 3080ma wich the series LED would see. So if anything one LED will be ever so slightly brighter than the rest, but nothing noticeable to the naked eye.


----------



## TorchBoy

Hej Henrik. Sorry, I thought the Hipflex was a buck driver, so it'll draw less current on in the input if the output is at a significantly lower voltage. I suppose I should have been a bit more meticulous and worked out the power on each side of the driver instead of doing it in one step...

Out: 2.8 A @ 14 V = 39.2 W.
In: 39.2/90% = 43.5 W @ 21.7 V = 2.00 A.

:thinking: Still works. I hope I'm not spoiling the thread with that, eh.


----------



## javiole

Hi,

I have got a question about this desing. I hope someone can help me out. First I am going to redraw Download diagram in a way that is easier for me to understand:







So far I'm using a board with 2 amc7135 and another one with 8 amc7135 with a switch in between so i can have a low (700ma) and a high(2800ma) modes (bicycle use). It works great but, it maybe an easier and simpler way to do it. 
It is possible to feed the AMC7135 board with a different voltage reference so the whole set of LEDS will dim. As in this mod of Download diagram:






The resistor R1 would put the voltage down to about 3.6volts, then the potentiometer, used as a variable resistor, would let you choose the voltage from about 3volts to 3.6volts. I understand that the amc chip has a very low comsuption, so R1 won't need to be bulky. Even the pot can be replace by several resistors to be switched to get different modes. Another advantage is that only two cables need to be pass throw the heatsink into the leds room. Can someone clarify if this would work? cheers

sorry for my poor skills drawing diagrams.


----------



## download

javiole, 
Just use this 8x 7135 driver, it has MCU (multi-level control IC). Like 3 or 5 mode.
Power on & off to change the mode you like, eg: High 2.8A, mid 1A, low 300
mA ......

Wiring is same as my original diagram. It will be fine.


----------



## TorchBoy

javiole, I _think_ you would get a very twitchy output. The AMC7135 drops out of regulation at 2.7 V. With a polarity protection diode that becomes about 3.3 V (not 3.6 V). Unregulated the AMC7135 may be a little unpredictable and I _suspect_ a very small change in the resistance of your potentiometer would make big changes in the output current, so you _might_ have trouble setting it as you want. The dropout voltage graph in the datasheet is about the only help it offers. Having said all that, it sounds like a very interesting way to use them. Give it a go and let us know if it's practical.

download, where is that driver from? I list it as "unsourced" since I've only seen a photo posted before (from Alibaba) but no retail links.


----------



## Aircraft800

TorchBoy said:


> javiole, I _think_ you would get a very twitchy output. The AMC7135 drops out of regulation at 2.7 V. With a polarity protection diode that becomes about 3.3 V (not 3.6 V). Unregulated the AMC7135 may be a little unpredictable and I _suspect_ a very small change in the resistance of your potentiometer would make big changes in the output current, so you _might_ have trouble setting it as you want. The dropout voltage graph in the datasheet is about the only help it offers. Having said all that, it sounds like a very interesting way to use them. Give it a go and let us know if it's practical.
> 
> download, where is that driver from? I list it as "unsourced" since I've only seen a photo posted before (from Alibaba) but no retail links.


 
That was the *3-Mode Regulated Circuit Board for Cree MC-E and SSC P7* sold by Shiningbeam.com SKU 1217. It has been removed from the site :thinking:


----------



## javiole

Thanks for the replies.
I tried a multimode board attached to a 1400ma amc board. It works fine but I prefer a simple toggle switch on-low---off---on-high. It is for a bicycle light. With a toggle switch I know if I the low or high mode are on (by looking at the toggle), and also I can pass from one to another easier. For example when a car ahead have the full beam, I can easy flash the low-high several times and the car would switch its lights down. I'll get some cheaper leds and I'm going to give a try to this one


----------



## trevlig

I did my Hi-off-Low setup like this.

The foru diodes in the pic is representing the four separate parts of one MC-E. The difference in light is quite small with this setup so I'll probably change it to 8 vs 2 AMC7135.

If you're driving more than one LED you can't use this setup... for my dual LED I've used download's setup.
I'm also into bikelights, so I see you're point in having a simple switch. In my case I have the flip switch on the helmet an a the multi-setup on the handle bar.


----------



## javiole

thanks for the reply trevlig,

I have used a 4 amc board for low and a dpdt toggle switch to add another 4 amc board to make the high. So I used in total 8 amc chips. As you mention, the difference is not that large and the cars were still complaining when the low level was on. I find that with a p7, 3 amc chips is ok for a low level ( 2 amcs is too low i think). For a tri-p7, 3 amc chips it's to bright so I use only 2, and it is ok. Enough light to be seen, to see few metres ahead and not to annoy the other drivers and pedestrians. In this way I needed a 8 amcs in a doble board for high, and 2 amcs on another board for low, and a spdt toggle switch. For a single P7, I finished up doing a low with 3 amcs and direct drive for high, using 3 18650 in parallel, so plenty of run time. I like that because it is very simple to implement, cheap (only a 1000ma amc board), and required very small room. With the tri-p7, direct drive it's more problematic from the point of view of number of batteries to be carried. If you use the high level very often, you will need at least 9 batteries to be safe in a 2 hours ride. So it is better to regulate the current and use 7 or 8 amcs, so that with 6 batteries you are ok for a 2 hours ride in the high beam.


Would someone program a PWM, with a momentary switch, were one long push is an ON, a short push makes a HIGH, another push makes a LOW, another push makes a HIGH and so on....... another long push is an OFF?
Simple and easy to use (same as if you were driving a car). I would put two remote switches, one on the top of the handle bars (normal use), and the other one on the top of brakes levers (on a road bike, very useful when descending and cars are coming to you, so you don't have to change your position to switch to the low-mode).


----------



## download

javiole, I guess you did not see George's works yet.
He got some coolest driver around here.
UI is excellent. Not the cheap way can compare. --------------------------- http://www.taskled.com/


----------



## javiole

yes, his drivers look great although the software seems a bit complicated. I thought to give a try to the hipflex. It has a duo mode that seems to do what i want:

"Constant Mode: A click turns on the light and further clicks toggle between low (L2 by default) and high (L5). From on, a press will turn off the light after a “safety delay” of about two seconds."

Thanks again for the advise​


----------



## download

A few 8x7135 driver boards was added to Multi-Sink post.


----------



## TorchBoy

download said:


> A few 8x7135 driver boards was added to Multi-Sink post.



Hm... From that thread, "It is time to build your own Mulit-LED Mag." Does that mean it'll have a bad 80s haircut? :naughty:

I've added a link to the driver list.

trevlig, you could avoid the doubling up of AMC7135s if you instead switched the positive to the Vdd pins, using a small diode to isolate the extra 6 chips from the 2 chip switch position. (Does that make sense?)


----------



## trevlig

TorchBoy said:


> trevlig, you could avoid the doubling up of AMC7135s if you instead switched the positive to the Vdd pins, using a small diode to isolate the extra 6 chips from the 2 chip switch position. (Does that make sense?)



I tried to do the first, but I didn't get where to put the V+ to the LED. :shrug:

Can you please write a simple chart, so that I might understand?


----------



## 2calif

*Poorman Mutli-Lux on Triple XP-G R5*



download said:


> Just found my (3x7135 multi-level) & (4x7135) boards have a different 7135,
> The (4x7135) that AMC7135 do *NOT* work with (3x7135 multi-level) controller IC.
> If your board like this and wire them together, the mid & low mode will have no light come out.
> 
> 
> 
> 
> 
> 
> Below is the way to make it work fine like 3x7135 + 3x7135 = ~2A output
> 
> 
> 
> 
> Download:twothumbs, I registered just now in hope to get an opinion from you regarding this 3x7135 + 3x7135 mod. I happened to have 4 of these drivers laying around and need to be put to good use.
> 
> I am looking to get the new TRIPLE XP-G R5 on PCB from Cutter's: http://www.cutter.com.au/proddetail.php?prod=cut937
> 
> To see the one I'm talking about click on XPG on MEPCB near top of the page, then scroll down to look at the picture. An YES you can get 20mm optic to fit these :huh:
> 
> How would you wire this with the 3x7135 + 3x7135 (2A) mod? I currently have two 7.4v li-ion packs.
> 
> Thanks, you guys are great :thumbsup:


----------



## 2calif

download said:


> Just found my (3x7135 multi-level) & (4x7135) boards have a different 7135,
> The (4x7135) that AMC7135 do *NOT* work with (3x7135 multi-level) controller IC.
> If your board like this and wire them together, the mid & low mode will have no light come out.
> 
> 
> 
> 
> 
> 
> Below is the way to make it work fine like 3x7135 + 3x7135 = ~2A output




Any thoughts on using this 3x7135 + 3x7135 mod on the new Triple XPG R5 on 20mm Star from Cutter?


----------



## download

2calif,

From the link, Triple XPG wired in serial setting.
Your two 7.4v li-ion packs do not match the basic rule:
1x 3.7V Li-ion to 1x LED.

Could you adjust battery pack to 10.8V?

Otherwise, you might modify the wire of MCPCB, 
like (1x LED) serial (1x LED parallel 1x LED)
So it will fit your 7.4V battery.
Not a perfect sulution..... 

A cheap buck driver (Kennan 2 - AX2002 4-23V) would do it better. 
https://www.candlepowerforums.com/threads/188227

Triple XPG <- AX2002 <- 7.4v li-ion packs x2


----------



## 2calif

Thank you Download


----------



## download

Add new driver in my Multi-Sink post:

AX2002 Multi-level driver
Size: 17mm x 8mm
Volti-in: 3.6V - 23V (0.25V higher than LED voltage)
Applications: 1-6 Leds  
Mode: 3 level, High=1A, Mid=200mA, Low=30mA with Memory mod. :huh:


----------



## TorchBoy

Sounds good. I'll add it to the driver list. Got efficiency figures?

BTW, don't forget to include "www." at the start of your links. The forum cookies don't like the URL without it.


----------



## download

Thanks TorchBoy, 
Efficiency is 80~90%.
http://www.micro-bridge.com/data/Axelite/AX2002.pdf


----------



## mrevolution

Hi new to this forum. Nice setup. I have a 2D Mag and can I just use 2 18650 protected batteries instead of 2D li-ion cells?


----------



## download

:welcome: mrevolution, 
Both 18650 & D size li-ion are same 3.7V, so you can use either without different for the driver & led. 
Just the D li-ion may run longer due to the higher capacity.


----------



## mrevolution

download said:


> :welcome: mrevolution,
> Both 18650 & D size li-ion are same 3.7V, so you can use either without different for the driver & led.
> Just the D li-ion may run longer due to the higher capacity.



Thanks for the warm welcome! From what I've read more and more, I can put 3C batteries in a 2D Mag? And can I use the li-ion? Where can I buy them?

Sorry for the noob questions if they are already answered

Thanks


----------



## download

You need to decide a few things first.

How powerful you want? 
eg: single die led, 4x die led, multi-led......

What battery type you like?
eg: 3x Ni-HM is very close to 1x Li-ion voltage 3.7V, 2x li-ion = 7.4V.......

What LED you will choose?
eg: Cree XP-E, MC-E / P7, SST-50 / 90

What driver you choose?
eg: Step-down driver (Battery volt is higher than LED) like 7135, 
Step-up driver (Battery volt is lower than LED)

Simple Suggestion: 
1. Mag3D 3x Ni-MH D -> 8x7135 -> heatsink -> SST-50 (~$35 led)
2. Mag2D/3C 2x 18650 -> 6x7135 -> heatsink -> MC-E M bin(~$20 led)
3. Mag2D/3C 3x Ni-MH C -> 4x7135 -> heatsink -> Cree XP-G R5(~$10 led)

Some excellent sample to show how to mod.

https://www.candlepowerforums.com/threads/195358

https://www.candlepowerforums.com/threads/212835


----------



## mrevolution

I want to try out just one P7 for my 2D Mag with 8x 7135, 3 or 5 mode, at 2.8A. I want to look for something that will have long run-time. What is your recommendation for batteries? 3C into 2D, 2xAA 18650 into 2D, or 6xAA enloop? What type is best for me?

Thanks.


----------



## download

mrevolution, 

P7 for my 2D Mag with 8x 7135, it needs ~3.7V from battery.
It can be:
1. 3x C cell Ni-MH = 3000-5000mA
2. 1x 18650 ~2600mA
3. 3x 14500 (3 parallel) = 3000mA

3x C cell Ni-MH will be the most easiest & longest run.
3x D cell Ni-MH would be even longer. ~10000mA


----------



## mrevolution

download said:


> mrevolution,
> 
> P7 for my 2D Mag with 8x 7135, it needs ~3.7V from battery.
> It can be:
> 1. 3x C cell Ni-MH = 3000-5000mA
> 2. 1x 18650 ~2600mA
> 3. 3x 14500 (3 parallel) = 3000mA
> 
> 3x C cell Ni-MH will be the most easiest & longest run.
> 3x D cell Ni-MH would be even longer. ~10000mA



Man you are GREAT! I think I will go with 3x C cell Ni-Mh.


----------



## powerup93

Ok, I've got a question download....or anybody else.

What do you think will happen if I use different Vf emitters? I've got 2 "J" and 1 "I" bin, and I don't know if it's ok to pair up. I figured, that I would hook up the "I" bin to the 7135 while the "J" bins, being a higher Vf closer to the 18650's nominal Vf, would work out better. If I remember correctly, my 7135 board supplies about 3.3v to the emitter regardless...I mean afterall, it is a current regulating rather than a voltage regulating board.

So, what do you guys think?


----------



## download

It will work as you said. In serial setting, 7135 limit the max current to the LED its connect, all outside leds just follow the max current. 
If it fit the basic rule like: 
1x Li-ion (or 3x Mi-HM) to 1x LED.
eg: 3x Li-ion (or 9x Mi-HM) to 3x LED


----------



## powerup93

Does anybody else notice any flickering? I'm hoping my wiring isn't loose anywhere or that my board is a bit faulty....but at low and medium, at least from what I can tell, there is some flickering. I think it's from one emitter and I do not know which specific emitter it is whether it's the "J" or "I" bin. On high, I can't notice or see any flickering. I think it might also be the battery neg spring contact or which I haven't found a really good spring or connection for yet.

And, it works nicely most of the time but it can occasionally run out of order. That is, that my board is only a low>med>high and sometimes it will jump around to a random order.

Also, I checked the batteries and even though I forgot which order I pulled them, two of the batteries read 4.00v while the third reads 3.88v. Does that sound normal or too far off by series batteries.


----------



## download

Some early circuit did have a few flicker/random issues. Maybe the frequency is not high enough.
Latest PMM circuit have high frequency that feel less flicker (like 8x 7135).


----------



## powerup93

That sux. I guess I might have bought an older one. I bought mine form shiningbeam, which looks to be exactly like the one you're selling...except his was cheaper  I only bought it like 4 months ago too. It keeps going out of stock on his site and I don't even know if it will come back.

I am really loving this setup and your tinkering and information are GREATLY appreciated!


----------



## powerup93

Is it safe to use 2xCR123 primary with the 7135? 2.8a is a high discharge rate though I think that li-ions can do atleast 2C. I have tried 2xCR123's in series, and my tested batteries are 2.90v+2.90v=5.80v and while in series they share the current of what I believe is ~1.5a+~1.5a=~3a discharge. 

Is it safe to use matched cr123's like this in a high discharge application?


----------



## download

7135 use with 2xCR123 primary in serial is possible. But not recommended, because battery side is ~6v, LED need ~3.7V only. efficiency 60%
The extra power will transfer to heat, a lot of heat! Just waste it.

So 1x li-ion is 3.7V ~ 4.2V(fully charged), it matches closely to the LED volt-in.
Less heat & save power. efficiency 90%

Use AX2002 like buck (step-down) driver will be better. efficiency 90%


----------



## pulstar

Hi, i'm wondering how to make my dreams happen I've got an idea of building a 3 x XP-G in a 3D(C) Maglite with ni-mh cells. Each cell can provide 1.2V so we have 3.6V to feed LEDs with. Since i really want to use nimh cells i need to play with current a bit. I really want to make everything by myself(to get additional soldering experiences and so on...) So, my ide is to drive LEDs in parralel config (each led gets enough voltage) and then wire three AMC 3175 in parralel config to each LED in series. That means that each AMC chip would be under the battery voltage and could provide 350mA of current. So, 3x350mA in parralel gives 1050mA to each LED. I still don't know if this could actually work, and even if, it would still be only one mode setup. Is there a way to make multimode setup only with, let's say, AMCs, and some basic elements? Has someone already made a (multimode) driver by himself to power similar led configurations?


----------



## download

Take a look. 

https://www.candlepowerforums.com/threads/195358


----------



## pulstar

Hi again,

i have another question (nooby) about AMC chip. Let's say that i have 6v power source and i want to drive one LED (Vf 3.7) with 350ma. Let's say i would wire one AMC 3175 and led in series. Because of the led's 3.7 voltage, would there be a 2.3V voltage drop on AMC chip (Kirchhoff's law: sum of all voltage drops (+sources) in one loop must be zero)? And even more, would my wiring have around 800mW power loses on AMC chip(2.3V*350ma)?
Should i use some of LM chips for such applications? 
Please note, this is all hypothetical...


----------



## download

Yes, exactly what you said, 2.3V*350ma = 800mW waste & transfer to heat!
That mean transform 60% to light, waste 40% to heat. :green:

DC to DC circuit should be more reasonable in this situation.


----------



## vestureofblood

Hi Download,

If I use this set up






And I remove 2 of the 7135 chips from your 3 mode driver to get 2.1 a rather than 2.8. Will the output on med and low decrease too, or will it only effect the high mode?

Does it matter which of the chips I remove?

Thanks


----------



## download

vestureofblood, 

If you remove 2 of the 7135 chips from 8x 7135, the med and low mode will decrease too. 
Whatever 2 chips the result will be the same.

This is exactly what I am using in Mag2.5C for a while, 6x7135 to MC-E with 2x 18650.
Current draw from fully charged battery end are 0.10A, 0.7A, 2.1A.
Each die have 0.05A, 0.35A, 1.05A. Total 4x die = 0.2A, 1.4A, 4.2A


----------



## vestureofblood

download said:


> vestureofblood,
> 
> If you remove 2 of the 7135 chips from 8x 7135, the med and low mode will decrease too.
> Whatever 2 chips the result will be the same.
> 
> This is exactly what I am using in Mag2.5C for a while, 6x7135 to MC-E with 2x 18650.
> Current draw from fully charged battery end are 0.10A, 0.7A, 2.1A.
> Each die have 0.05A, 0.35A, 1.05A. Total 4x die = 0.2A, 1.4A, 4.2A


 
That is music to my ears. For me this opens a whole new world of possibilities for this driver. I was afraid it might only lower the high mode, and then high and med would look almost the same. The 2 li-ion with one neutral white MCE was exactly what I had in mind.

Have you tried adding additional 1400ma boards to this to get a higher current with multi mode (like netkids stuff)?


----------



## download

For 6x 7135. 4.2A to 1x MC-E is near its limit. It is really bright!!!
You know 1x MC-E is recommanded to 2.8A only. 
Both NetKidz & StefanFS mod do work very well. We share the same concept.


----------



## vestureofblood

download said:


> For 6x 7135. 4.2A to 1x MC-E is near its limit. It is really bright!!!
> You know 1x MC-E is recommanded to 2.8A only.
> Both NetKidz & StefanFS mod do work very well. We share the same concept.


 

I was actually thinking that maybe I could use one of your boards and 2 or 3 1400ma boards in combination to build a multilevel driver for an SST 90.

I am just not quite sure how to wire it so that I still have the multilevel, and if it does work, would the dimmer effect all 4 boards on each mode?


----------



## download

The concept is OK, but not all li-ion could delivery enough current.

NetKidz show how it wires:
https://www.candlepowerforums.com/threads/192677

I did not try more than 2.8A yet. Sound interesting.


----------



## vestureofblood

For the SST board I would probly run 4 nimh C cells rather than li-ion.

I guess when my drivers arrive I will look at them again, right now until my wallet fattens up I will probly just stick with what I know works, and do the "just try it" stuff when I have the money to risk if its.


----------



## Mettee

the very first light that I built used a three board set up, one multi mode and two slave 7135 boards with one chip removed from each slave. 

The new 17 mode can be made to 1400ma and if you leave the chips on the slave boards that is another 1400x2. 4.2A. 

I am planning on trying the same thing you are thinking, I am sure it will work somewhat but the battery may have trouble keeping up with current unless like you said you use nimh.


----------



## vestureofblood

Edit: NVM


----------



## vestureofblood

Hi Download,

I just wanted to double check and make sure my thinking is correct on a wire path.

If I wired 3 MCE emitters in this pattern DD, would all of the dies get equal current?


----------



## TorchBoy

*Re: Poorman Multi-Lux setup method*



vestureofblood said:


> If I wired 3 MCE emitters in this pattern DD, would all of the dies get equal current?


No, you've got two paralleled LEDs in series with a third. The two in parallel would share the current that all goes through the other LED.


----------



## vestureofblood

Hmmm, I sort of thought that might be to good to be true. What you are saying is that if the first emitter was getting 4 amps the next two would get only 2 amp each?

Guess I better stick with what I have. Right now I did basically the same thing but I split the second emitter in 1/2 giving 6 die on each side. This works fine but its a lot of very tiny connections using a thing gauge wire. For a minute I thought I came up with a way I could use some much thicker wire.


----------



## TorchBoy

vestureofblood said:


> Right now I did basically the same thing but I split the second emitter in 1/2 giving 6 die on each side.


:thumbsup: Look on the bright side (no pun intended) - it's good soldering practice.


----------



## download

Or you could wire like this, but some MCE Volt-in is quite low.
May  within 0.5 sec.


----------



## download

Actual wiring diagram for ref.


----------



## TorchBoy

download said:


> Actual wiring diagram for ref.


Getting better and better. Now how about passing only the 200 µA Vdd current through the Mag switch?


----------



## download

It may affect the mode changing if letting small current to the driver. 
Because it stay alway ON. :shrug:


----------



## TorchBoy

If the switch isn't feeding power to the Vdd pin the driver wouldn't be on, so the second LED (counting from battery positive) wouldn't be on, so the LED series wouldn't be on. The problem is that you'd need to drop the voltage fed to that pin, for which you could use one of the LEDs.

In other words, shift the Mag switch to the blue wire just above the words "Driver out LED(+)" and it would work fine but with next to no current on the switch.


----------



## vestureofblood

Hi Download,

Do you happen to know which chip on the multimode 8x 7135 boards is for the reverse polarity protection?


----------



## download

Next to the Output to LED+ is a diode, it is for the reverse polarity protection.


----------



## vestureofblood

Thanks, that is what I suspected. I wanted to use one of these boards as a single mode with the controller and extra chips removed, but still enable the rev poll protection.


----------



## SmurfTacular

download said:


> Actual wiring diagram for ref.




That is a really useful diagram. But does it have to use an MCE??? What if I put in a P7 instead? Because I have about twenty P7's on hand, and about five of your 7135 drivers, and I want to use them. Is there any way of driving a single P7 with one or two of your 7135 drivers?


----------



## download

Here is the 1xP7 setting. 1x Driver to 1x LED with 1 battery (or parallel more), Max.2.8A to LED. 
Parallel more battery will extend the run-time.


----------



## SmurfTacular

*Re: Poorman Mutli-LED setup method*



download said:


> I found some interesting setup method to use the cheap driver board like 7135.
> It can be used multi Seoul P7 or Cree,
> like 2x li-ion to 2x LED or 3x li-ion to 3x LED.
> It works quite well for me. Hope it helps you too.
> 
> 
> 
> 
> 
> Each P7 can get 2.8A !!!
> ]



if you wired that driver with the 5 mode setting, do all the LED's change when you change modes? Or does just one change?


----------



## download

*All* the led's will change the mode at the same time.


----------



## owent

download said:


> Actual wiring diagram for ref.


Hi all i am new to the forum and to building LED lights, looking to build a headlamp using this set up



would a shining beam driver sku 1217 be good to run this set up? how would i wire it so as not to exceed the 6v max for this driver would be using the two 18650 bat shown.
like i said new to this and it is still all a little over my head.
Thanks


----------



## TorchBoy

owent said:


> would a shining beam driver sku 1217 be good to run this set up? how would i wire it so as not to exceed the 6v max for this driver would be using the two 18650 bat shown.


No, that diagram appears to be wrong - you really want a 1.4 A driver for that configuration. The way it's arranged two dice of the LED drop (almost) half the voltage before the driver and the two dice that are controlled by the driver, so the full voltage of the two cells isn't seen by the driver.

You could use that driver if you wired all 4 dice in the LED in parallel and used just one Li-ion cell - see the diagram in post 236 above.


----------



## owent

Thanks Tourchboy yes i see and understand the other setup better is it an accepted practice to run lithium's in parallel as this single battery i am sure will not have a long life span before it is flat.
That is put 2 in parallel to get a longer run time.

With you experience could you suggest a set up that would be good for me, my aim is to make a powerful head lamp for when i am hunting when i am walking out of the forests after night fall.

Was looking at a single MCE with two 18650 cells what has me stumpped is the driver and then of course how to wire it.

From all the reading i have done over the last two weeks on this forum i have a basic idea how it all works but still learning.

Would you have any suggestions that would maybe fit what i am looking for any ideas welcome.
I like the cree products so tend to want to go with them.
My other concern is the heat issue as most of the time i will be walking so no great air flow and the ambient temp where i am is hot in the summer time. So whatever i do will have to not get out of control hot but at the same time looking for the brightest option i can get.


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## TorchBoy

As it sounds like you've realised, the simplest way to wire it would be with the MC-E's dice in parallel and the Li-ion cells also in parallel, and use an 8xAMC7135 driver (such as is available from CPF user Download). Some other medium-high current linear driver suggestions.

If you haven't already bought the MC-E, I made a headlamp a couple of months ago using three XP-Gs in one of DX's GU10 housings, with each LED driven by a 3x AMC7135 board, but one of the drivers has a multimode controller which I've used to control all three boards. Low mode is easily enough for navigation, high mode is 1,000+ lumens. That should be powerful enough.

As a completely separate idea, if you want a great spotlight for hunting try the 66 mm aspheric lens from DX with an XP-E - that combination gives a very narrow beam.

BTW, :welcome:


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## ergotelis

Guys do you think that it will work fine with 4 low vf xp-g? I am planning to connect the first in a 3x7135 driver and the next three following like the diagram. It will work, but will it be fine? Will it manage to hold well the regulation?What do you think?Heat?
Battery source is 4 lion!


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## TorchBoy

*Re: Poorman Multi-Lux setup method*



ergotelis said:


> Guys do you think that it will work fine with 4 low vf xp-g? I am planning to connect the first in a 3x7135 driver and the next three following like the diagram. It will work, but will it be fine? Will it manage to hold well the regulation?What do you think?Heat?
> Battery source is 4 lion!


Using four lions for power... :huh:








Typical Vf of an XP-G at 1 A is 3.3 V, total for three in series 9.9 V. Total battery voltage when fully charged 16.8 V, meaning 6.9 V across the driver and last LED (probably only 6.3 V allowing for a polarity protection diode). That's a little too much. I think adding another AMC7135 driver in series would work if they were well balanced (if you had one driver trying to do 1,050 mA and the other 950 mA you'd have most of the voltage drop across the higher output driver).

With multiple series LEDs you also need to stick to single mode.

There will be quite a lot of heat. 3.3 V * 4 LEDs * 1 A = 13.2 W, with a good chunk of that heat.


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## deadrx7conv

After reading this, I now have a solution on how to power multiple LEDs from a 12v(11.5-13.2v) deep cycle marine battery. I just received my 20pack of 1400mah amc7135 drivers. http://www.dealextreme.com/details.dx/sku.3178

Now, wonder if a couple of these can be wired in series to work the same way? Just ordered 2. 
http://www.dealextreme.com/details.dx/sku.20330


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## download

owent, ergotelis



 This setup works for me more than 2 years. MC-E with 2x Li-ion
Remember, 1.4A/die to MC-E is huge current. Take out 2 chips will be better. (1A/die) Multi-level driver is highly recommended. 
Because you could switch to Mid or Low mode to get longer runtime and generate less heat from LED.
For High mode run more than 2 mins, you need BIG heatsink!!!







And tx101 use 4x XPG with 2x li-ion too. 


https://www.candlepowerforums.com/posts/3401836&postcount=434


tx101 said:


>



Suggest you guys try to wire it. Simple & cheap anyway.


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## TorchBoy

download said:


> owent, ergotelis
> 
> 
> 
> This setup works for me more than 2 years. MC-E with 2x Li-ion
> Remember, 1.4A/die to MC-E is huge current.


The problem is your diagram says 8xAMC7135, which is (nominally) twice 1.4 A.


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## download

Take a closer look, 2 dies/led is parallel wiring.
It shares 2.8A current form the 8xAMC7135 board.
1.4A per die/led, isn't it?


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## TorchBoy

*Re: Poorman Multi-Lux setup method*



download said:


> Take a closer look, 2 dies/led is parallel wiring.
> It shares 2.8A current form the 8xAMC7135 board.
> 1.4A per die/led, isn't it?


Sorry, I can't tell if that's sarcasm. It's rated at 700 mA per die. You're running a 2P2S arrangement, so it should be a total 1.4 A at twice the voltage (2 Li-ion cells in series).

And that darn "Mu*tl*i-Lux" in the subject line keeps coming back. 

Edit: Are you saying you're running it at twice the max rating? Do you really think you should be recommending that for beginners?


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## download

Thanks for reminding.
It shows many possibility if you have enough imagination.
We are sharing what we found and hope it helps other only, right?
:thanks:


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## owent

thanks guys for the input think i am going to go with the L31-a from lux rc been looking at that and have seen some of the lights been made on mtb forum really small and bright with integrated board and led for me as a beginner think it will work out good and i can keep the size down dont want to be carrying this huge contraption on my head :tired: hopefully this is only the beginning!!


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## TorchBoy

*Re: Poorman Multi-Lux setup method*



download said:


> It shows many possibility if you have enough imagination.


Which reminds me - I'm still waiting for one of your cool drawings showing my headlamp setup of a multimode driver controlling two other single mode drivers, each driver controlling one of three LEDs, and all driven from 4x AA. Any chance of?



owent said:


> think i am going to go with the L31-a from lux rc


They look like nice little units.


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## Aircraft800

tx101, download,

In this setup, the Poor man setup 3 wire:



Does the common wire to all 4 emitters (in the middle left) get attached to the Batt "+" spring or to the LED "+" terminal? Are they the same? If I attach it to the spring, do I just omit the LED "+" lead (lower left)?



Thanks for the help!


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## download

Aircraft800, 
Yes, connect to LED "+" terminal is correct. Or LED "+" lead will get the same result.
Because both are connect each other in the circuit.


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## Aircraft800

Thanks! I tested it out, and it worked fine.


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## Aircraft800

Is there any way to run 4X XP-G's off a 8x 7135 driver and 4X NiMh cells with a LED parallel setup? I can't figure out how to get the amperage at 1.4?

After thinking about it, 4 XP-G in parallel would give me 700 mAh per die off this driver, right?


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## download

Aircraft800,

Yes, 4 XP-G in parallel would give me 700 mAh per die.

Or use 6x NiMh cells = 2 x Li-ion wire like this, it will give 1.4A per die.


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## kingkong

download,

Can i use the same 8-7135 to drive multiply MC-E? I just need to add more batteries.. is this the correct forumla?

1 - MCE = 2 Li-ion
2 - mce = 4 Li-ion
3 - MCE = 6 Li-ion


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## HKJ

kingkong said:


> download,
> 
> Can i use the same 8-7135 to drive multiply MC-E? I just need to add more batteries.. is this the correct forumla?
> 
> 1 - MCE = 2 Li-ion
> 2 - mce = 4 Li-ion
> 3 - MCE = 6 Li-ion


 
This depends on how you wire the MCR, a MCE contains 4 leds that can either be wire as 4p, 2s2p or 4s. 1s is one LiIon battery, 2s is two LiIon batteries. Each led can take the current from two 7135 chips.
This means a 8-7135 driver needs the 4p configuration with one LiIon battery. Two MCE in series each with 4p will require two LiIon batteries and the 8-7135 driver.


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## download

As HKJ said, wire the MC-E (internal 4 leds) parallelly as 1x P7 and connect like below. 





1 - MCE = 1 Li-ion
2 - MCE = 2 Li-ion
3 - MCE = 3 Li-ion


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## kingkong

download,

Thanks for a nice drawing! what software do you use to draw?

Do you think the formula with work with 10 mce and 10 Li-on? am I pushing it too much?

1 - MCE = 900 lm
10- MCE = 9000 lm 

kong.


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## download

Hi Kong,
It is CorelDRAW.
I'm afraid 10x li-ion are too much voltage for the driver.
But I did not test 10x yet.


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## kingkong

Download,

I am trying to build a camping light. do you know the max number of LEDs the driver support?

kong.


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## download

If you do not push it too hard, 4x led to 4x li-ion should be ok.


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## billi

download said:


> Here is the 1xP7 setting. 1x Driver to 1x LED with 1 battery (or parallel more), Max.2.8A to LED.
> Parallel more battery will extend the run-time.



I am planning to build my first LED with two parallel 18650(s) and this is exactly the way I was planning to do that. Can somebody tell me if there are some negative sides of parallel connection? In my (non-expert) view this design has only advantages over the classical in-series connection:
1) Vin is close to Vout (higher efficiency?)
2) All batteries have exactly the same voltage drop (even discharge?)
3) More drivers are available for 3.7-4.2 Vin, and they are cheaper than 3.7-8.4 or 3.7-18 drivers.

So, where is the catch?


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## kingkong

Download,

Thanks for all you help! I will build a 4 MCE using 4 Lion with a CPU heatsink...

kong.


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## download

billi, :welcome:
No bad side if wire parallel with protected li-ion ONLY.
No no no for unprotected li-ion wire as parallel connection.
1. yes
2. yes
3. It depends what you need, too many options
eg. 3x li-ion to 2x led, the situation cannot be applied in this case.

kong, the CPU heatsink may need the fan too.


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## kingkong

Download,

Thanks for all you help! I will build a 4 MCE using 4 Lion with a CPU heatsink...

kong.


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## billi

download said:


> billi, :welcome:
> No bad side if wire parallel with protected li-ion ONLY.
> No no no for unprotected li-ion wire as parallel connection.
> 1. yes
> 2. yes
> 3. It depends what you need, too many options
> eg. 3x li-ion to 2x led, the situation cannot be applied in this case.
> 
> kong, the CPU heatsink may need the fan too.



Thanks for your answer, download. 
What can happen to unprotected batteries? Is it something specific to parallel setup?
Meanwhile I see no reason why serial connection is so dominating... any advantages over parallel one?


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## download

billi,

Thanks for member share his experience, so we could learn a lot before we make the same things.
TK Monster Explosion - unprotected battery in serial connection issue:
http://www.candlepowerforums.com/vb/showthread.php?262234-TK-Monster-Explosion

In parallel setup, battery will balance each other continuously.
It performs better if the all cells are same condition like capacity, ages......
If one cell is bad, all parallel cells will charge the bad cell, and lost the capacity too.


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## kingkong

Download,

Thank for the link to the Li-ion battery problem.. 

if i want to use car battery ( 12v), does it equal to 3 cell or 4 celll li-ion?

kong.


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## VegasF6

*Re: Poorman Mutli-LED setup method*



download said:


>


 
Ok guys, I thought this would be simple, but I am obviously doing something very wrong. I am trying to light 4 leds using a simple 1 mode 1*amc7135 driver. I am using the above picture as a model, the first 3 leds drop voltage then input to the 7135 driver and out to the last led. My power source is variable bench power supply and I have tried from 9V to 16V. What I am confused about are the lines to the top P7 led, where exactly do they go on the driver? 

I made a very crude drawing of my setup here:





The problem lies in LED #4 which is connected to the driver. Where exactly do the red and black leads go? I have tried several different ways and they result in leds 1,2 and 3 lighting dimly and #4 not lighting at all. Obviously I am doing something wrong. I have tested all 4 leds and they are ok.

Currently I have the positive lead of led #4 connected to the driver out that is connected to the left pin on the IC and I have the negative lead of led #4 connected to the outer ring of the driver, common to my power supply ground. 

Let me know if any of that is clear.
Thanks!


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## download

kingkong,
Car battery 13.2V(car idling) - 12V(Engine off)
Li-ion 4.2V(Fully charged) - 3.7V
Car battery is near to 3x Li-ion.

VegasF6,
Try this:


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## VegasF6

Got it download, thanks. Sleeping on it helped  Then I saw your post, and that's correct.


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## billi

Wow,
Thanks for the link. What do they say?... one image is worth a thousand posts ...


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## kwarwick

This solution seem too good to be true, but after reading through the thread in detail it seemed like it was working for many people so I figured I'd give it a try for my application.

Tonight I tried using this setup to drive 3 x XMLs. Wired per the original post using a Shiningbeam 8x7135 board and three 18650s, the driver got very hot and started smoking in less than 20 seconds! I was measuring current draw from the batteries and it was under 2.8A so I'm not sure what went wrong. Just to make sure I didn't just have a bad driver I tried another but only let it run for a couple of seconds and I could see it was getting extremely hot so I curtailed my experiment to avoid frying a 2nd driver.

Any thoughts why this went *poof*? I'm thinking it might be due to LEDs with low vf causing the 7135 chips to work overtime or exceed their maximum voltage?


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## MikeAusC

kwarwick said:


> . . . . Any thoughts why this went *poof*? I'm thinking it might be due to LEDs with low vf causing the 7135 chips to work overtime or exceed their maximum voltage?


 
Yes, the XM-L has much lower voltage drop than earlier LEDs - this means that with the same battery voltage, there's more voltage and therefore power being dissipated in the 7135.


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## kwarwick

MikeAusC said:


> Yes, the XM-L has much lower voltage drop than earlier LEDs - this means that with the same battery voltage, there's more voltage and therefore power being dissipated in the 7135.



Darn, I was afraid this as the case! Now I need to figure out another driver solution for the DRY 3 XML host I'm trying to build up. Very challenging to find a driver that will handle 3 XMLs driven by 3 Li-ion batteries.


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## download

ma_sha1 did it, he added a resistor inline successfully. :thumbsup:

http://www.candlepowerforums.com/vb...-Yard-Sweeper-Mag-2C-3-mode-with-3x-IMR-22430


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## OldNick

MikeAusC said:


> Yes, the XM-L has much lower voltage drop than earlier LEDs - this means that with the same battery voltage, there's more voltage and therefore power being dissipated in the 7135.



Just OOI, is there _that_ much extra work to be done? As I see it (may be brain fart day) if the voltage were half (4:2), there would only be a bit extra.....unless the chips are rtight at their limit at 2.8A. At 2.8A should the chips not be heatsinked anyway?


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## Justin Case

download said:


> ma_sha1 did it, he added a resistor inline successfully. :thumbsup:
> 
> http://www.candlepowerforums.com/vb...-Yard-Sweeper-Mag-2C-3-mode-with-3x-IMR-22430


 
It is unclear to me that this is a good way to go. Adding a dropping resistor can be viewed as analogous to a flashlight with very high parasitic resistance. The impact of high parasitic resistance is reduced run time in regulation when using a 7135 based driver. VanIsleDSM has shown this conclusively here.


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## brad72

kwarwick said:


> Darn, I was afraid this as the case! Now I need to figure out another driver solution for the DRY 3 XML host I'm trying to build up. Very challenging to find a driver that will handle 3 XMLs driven by 3 Li-ion batteries.


 
What about the LFlex from taskled. Looks like you can drive 3 XML's from a 3S li-ion pack without any problems


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## kwarwick

Apparently LFlex would have a similar problem as using 7135 based drivers since it is also a linear regulator... at 3A driver current there would be something like 9W of waste power that would need to be burned off by the driver. That's well outside what the LFlex was designed to handle and would likely go *poof*. Need to find a buck driver that can handle a load of about 30W without melting down. Oh and it has to be 1.1" in diameter, which unfortunately rules out the H6Flex.


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## JonnyC

Hey guys!

First, thanks for the wealth of information here! I'm looking to build my first multi-emitter light using inexpensive parts (including the batteries), and I'm glad I found this thread. I would prefer to run it on Eneloops, so pushing an individual current controller for each XM-L or XP-G is not doable (would have to push 4.5 to 9 amps). All of my existing lights use a 7135-based board, so I've run 3xAA's or 1xLi-Ion in all of them. This will be the first time I will running anything with more than 4.2v.

After studying this design, the more and more I got concerned about voltage to the micro-controller (MCU), and basically baffled at how this setup was able to work. After thinking about it most of the day (including at work, ugh) and breaking down the components, I think I finally understand it. I think separating the components out in a diagram helped a lot, instead of lumping in the driver board as just one component. Now all of this may have been covered, and I did read every post, but it took me thinking about it myself to actually understand.

Here is the original poorman's setup (at least for P7s)





Awesome, right?! :sick2: That's my mspaint skills right there. I only show it as one battery, but picture it as three. And the 7135 would be more than one in parallel depending on the amperage you want.

However, I think this shows you:

1. How the 7135's are able to regulate amperage for all three LEDs
2. How the two top LEDs reduce voltage to the MCU so it doesn't get killed by the battery

After looking at this, here are my concerns/questions:

1. After voltage is used up in the top two LEDs, any left over will be what the MCU sees. The MCU only draws a few milliamps if that, so the forward voltage/voltage drop on the LEDs will be at the minimum (if I understand LEDs correctly). We just have to make sure the battery voltage minus the minimum LED forward voltage does not exceed the max voltage input on the MCU. And note, as MCU starts switching the 7135's on through PWM, the forward voltage on the LEDs will increase, causing less voltage to go to the MCU (and even lesser voltage as the batteries are under load).

2. If the MCU is programmed with a very low mode (uses PWM to more slowly switch the 7135s on and off), with very low current running through the LEDs, the voltage drop through them will be lower as well. This means the lower the low mode gets, the more voltage needs to be burned off by the 7135s.

Is that all correct? I may have made some really bad assumptions and none of that is right 

Now, here's what I thought to address my concerns:





Basically, you power the MCU independent of the rest of the circuit. But in order to reduce the voltage to the MCU, you use a basic voltage divider using two different resistors (would need to be spec'd based on battery voltage). Since the MCU draws so little current, this should work. On all of the 7135 boards I've seen, you can remove a diode in order to separate the MCU power source from the LED power source.

*After all of this thinking, I realized my new design with the voltage divider doesn't really gain me much! Dammit!* As long as you know the battery voltage minus the lowest Vf of the top two LEDs won't be over the MCU limit, there's nothing to worry about. The main concern after that is making sure the 7135s are burning up too much excess voltage, which is the difference between the total Vf and Vbatt.

If this post doesn't help anyone and just clutters the thread up, I will gladly delete it 

- Jon


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## Mr Happy

Your voltage divider idea could work in principle, except as you have drawn it it is not "dividing" any voltage. You would have to connect one end of the divider to the other side of the battery to do that.

But the divider is not really necessary. As long as the PWM is running many times a second the voltage seen by the MCU will average out. Batteries have a significant time constant and they can't change their voltage as fast as the PWM can switch on and off.


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## vestureofblood

Hey all,

I dont really have the in depth knowledge of how each of the chips works etc, but here is something I can tell you. 

This multilux setup works great as long as the voltage of the LEDs is very close to the battery VF. Even with this when driving multiple LEDs such as 3 XML on 3 li-ion or 4 XML in a 2S 2P on 2 li-ion. You have got to heat sink the chips on that board very very well. If you dont after about 30 seconds runtime the chips/board get hot and the current falls like a rock. It falls so fast you can almost hear that whistling noise like Wiley coyote off a cliff.

I use the boadr that has chips on both sides so I heat sink both sides. To get a truly stable current beyond the one or two minute mark I used thick copper plates on both sides. Just sticking the board to the sidewall of the light with a piece of chewing gum wont do it for this one.  My 2 cents.


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## JonnyC

Yeah, I'll forget about the voltage divider. I'm rather challenged when it comes to understanding electronics 

Thanks for the advice vesture. Maybe I'll think about getting those sinks from The Sandwich Shoppe that mount to the side of a Maglite.


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