# powering LED flashlights with 220 V~



## druitre (Jul 18, 2009)

Hello,

this is my first post and I make it after first reading many posts for many days, trying to find the answer to my questions myself. Alas, I couldn't find it... very probable that what I'm asking is already explained somewhere, so any pointers towards appropriate threads are welcome too.

My question is (since I'm new to this whole field and no expert on electronics I'll try and keep it clean and not use any lingo that's bound to confuse me more than you):

What do I need to do if I want to run a LED flashlight in the CREE XR-E or SSC P7 category not on batteries, but on a 220 volt ~ powersupply?

(To explain: I want to use those lights in a miniature-photography job, where they'd have to be on maximum brightness for many hours at an end. But not have to constantly refresh batteries as they run out. I've looked into scratch-building the whole thing by buying separate components; the emitter, the heatsink, the lens, the powersupply, the housing, etc. But I've come to the conclusion that probably it's a lot easier to just convert a battery-run flashlight into a 220 V driven one.)

Any and all help much appreciated!

Jasper


----------



## SemperFi (Jul 18, 2009)

Hi Jasper, 

It is interesting at what you wish to see available on the market, may just be feasible but given the technology to be housed or "encased" if I may be more precise, functioning on a 220v outlet is truly an alternate source and perhaps, would serve well too. Once that is ever made applicable to suit any individual's needs & uses, I'm sure a 12 and/or 24v would serve well too for the vehicles. 

It will be *very costly* I believe and the manufacturers would have considered that option if there were no others, but there are, however, not having to work on or through LEDs in particular. 

Since you mentioned about yr side on the purpose, may I suggest you look within the Photographic Accessories for a similar solution that runs on / through the mains and also, allows you to have near natural colors to guarantee the saturation and ambience of the object and its immediate surroundings. It cost far less which is affordable and its as good as something in the range of 300 - 1000watts of blinding halogen lighting that is variable too on the output.

Check this link and its far cheaper a solution>>: http://www.expandore.biz/product_de...deid=&catid=9&brandid=64&formatid=90&start=11 

I hope this helps and wish you find a solution for your needs soon. :welcome:


----------



## Illum (Jul 18, 2009)

I think your better off building a fixed LED light from scratch...

running AC into a DC light will fry whatever thats in it, LED included

I'd recommend dedicated constant current drivers that's designed for 220V
Something like this: http://ledsupply.com/lt-901010350pu.php
would allow you to drive up to 8 LEDs at 350ma and depending on design there are many forms of optics/reflectors you can choose from for CREE XR-Es to fit your application. 

Can you give us some insights as to what your planning to do with the light?
Is it going to substitute a studio light?


----------



## Marduke (Jul 18, 2009)

Easy, just use an AC/DC power supply that puts out the correct voltage for the light.


----------



## Illum (Jul 18, 2009)

:thinking:


----------



## druitre (Jul 19, 2009)

Hi, thanks all for the answers.

@ SemperFi: I looked into the regular film and video equipment first, and then found out about the LED option.

@ Illum: I think you misunderstand me, I'm well aware of what kind of voltage and current is needed for the different types of emitters. And that putting 220 straight into a flashlight would be spectacular, if only for a very short while.  What I don't know is what do I need to put between the walloutlet and the flashlight to make things not go POOF. I'm confused by all the options I encounter when researching into this.

@ Marduke and Illum: exactly, that's what I want but I'm confused about what components do I need to do it - does the stuff already in the flashlight interfere with the stuff in those power supplies?

To make things a bit more clear I'll tell you about my idea:

My project entails shooting miniatures (around 50 cubic centimeters in scale maximum, more often 30 cubic centimeters) with a Canon 5D MarkII camera, using it's HD video capabilities (it's a filmproject). A friend will build the miniatures, together we'll do the shooting, after that I will do the post with 3D animations and compositing.

Most filmequipment is massively oversized for this kind of work. There is specialist equipment available, but it comes at a price - around the $1000 mark for a set of Dedo-lights, for instance. (Those are small dimmable halogenspots)

In most cases, crews would rent that kind of equipment but in my case, I'll be shooting for a straight run of two months and on a shoestring budget.

I then found out about the LEDs and their advantages: 

- they're small so will fit into hard to reach spaces within the miniatures
- they don't generate the large amounts of heat that halogens do (often enough to melt miniatures)
- they're much, much cheaper
- good colortemperature
- well focused/ able to throw the light where I want it

Well, stuff like that.

At first I wanted to buy five or six flashlights in the 200 lumens range (since that's what was available at my local filmequipment vendor - O-Light TR25's to be specific). I then learned about the runtime these have when on full - about two hours, wich would mean constantly replacing and recharging batteries. Can be done, but not too practical on a set.

I then digged into it and found out (through these forums mostly) that all the components are available separately so I can build my own lights. Buy some XR-E Q5 or R2 emitters (or MC-E's or ssc P7's), lenses, heatsinks, put it all in some encasing, connect it to an external powersupply that will take 220V~ as its input, and hey presto!

I also ordered one XR-E on a small board with some electronics (that would be called a driver, I guess? It allows me to put 8 - 12 volts at it's input and it will shutoff in case of overheating) at a local mailordershop and connected it to a regulated power supply at a friend's, and WOW it works. It even works when I connect it to an old powersupply for a harddisk I had lying around.

But now I need to put that emitter and the lens and the heatsink it's on into something tubular and sturdy to hold all components in place. Something that I can use on my filmset without fear of it breaking, that I can put in a clamp onto a tripod or somesuch. Something suspiciously looking like a flashlight 

That's why I came back to the flashlights: I think those flashlights are built exactly like the thing I need to have and I doubt I can do that kind of encasing better if I have to do it from scratch. I just don't want them to run on batteries.

The powersupply will NOT be in the flashlight but rather, I'd like to build one central powersupply-unit, 220V~ at the input, and five or six outputs where I can take a cable and plug that into one of my modified flashlights (the other end into the powersupply ofcourse), and one on/off switch on the main supply for each output. (To make them dimmable would be even better, but it's not my main concern).

I've looked into converters and power supplies, for instance this:
http://www.led-tech.de/en/LED-Contr...-for-5-8x-3W-LEDs--230V--LT-1282_118_119.html
but I don't understand if this still needs a constant current supply like this: http://www.led-tech.de/en/LED-Contr...Power-Supply--700mA,-30V--LT-890_118_119.html
behind it to make things work. Or some other part that I'm not aware of. Or if the electronics in the flashlight will interfere with the electronics in the power supply. Or how to rig it so that I can connect and disconnect lights while the whole thing's powered up.

Lots of questions, and some of 'em quite dumb I suppose, but hopefully I've explained myself a bit better now.

Cheers and looking forward to your suggestions,
Jasper


----------



## SemperFi (Jul 20, 2009)

Thank you Jasper and esp. on elucidating deeper at what your objective entails & basically requires to pull it through... in a smallish environment yet remaining illuminated endlessly due to the constant power delivered. 

I wonder if a goose-neck solution (tentacles from a common plate but nicely & conveniently hidden from the cameras' view) will be yr answer and certainly, an electronics specialist would be an asset here with yr project. Interesting indeed and I do wish you all the success you gain as well as a learning curve on yr progress both for you and all who follows yr achievement down the trail... incl. myself too.:twothumbs


----------



## Tony Hanna (Jul 20, 2009)

druitre said:


> What I don't know is what do I need to put between the walloutlet and the flashlight to make things not go POOF. I'm confused by all the options I encounter when researching into this.



I may be way off here, but if you use lights with drivers that are good to at least 12v (shouldn't be a problem as I've seen P60 drop-ins good to 18v on DX), then why not run them off of a car battery charger with a small SLA battery in the circuit to absorb the line "noise" from the charger? I used the same method in the past to run car audio equipment in the house and it worked pretty well for that.


----------



## druitre (Jul 20, 2009)

SemperFi said:


> (...) I wonder if a goose-neck solution (tentacles from a common plate but nicely & conveniently hidden from the cameras' view) will be yr answer (...)



You've outguessed me! I'll be using microphone stands/goosenecks/clamps since all that stuff is made almost to the same size as flashlights.



SemperFi said:


> (...) and certainly, an electronics specialist would be an asset here with yr project. (...)



Well, I was hoping to find a few of those hereabouts :laughing:


----------



## druitre (Jul 20, 2009)

> if you use lights with drivers that are good to at least 12v (shouldn't be a problem as I've seen P60 drop-ins good to 18v on DX), then why not run them off of a car battery charger with a small SLA battery in the circuit to absorb the line "noise" from the charger?



Interesting, can you explain this a bit more? What's an SLA battery? I don't have a car battery charger, is there a specific reason to use one instead of an adapter (220V AC in/12 V DC out) like the harddisk-one I mentioned?

And how do I know if the driver in a flashlight is good enough?

Thanks, Jasper


----------



## Tony Hanna (Jul 20, 2009)

SLA = sealed lead acid. I might be using that improperly, but what I'm talking about is a 12v "gel cell" or similar. You could also use a regular car battery but there are acid spill concerns in the event that the battery should get overturned. The only reason I brought it up was that the battery can help clean up some of the "noise" generated by converting AC to DC. If I were doing something on a budget, the battery/charger idea would probably be the first thing I'd use just because I have both. If not, then maybe a power supply out of an old PC... If your hard disk power adapter works then that's cool, but you'll want to check it's capacity to see if it will be capable of powering the number of lights you want to use.

As for the driver, I don't think it's so much a matter of "good enough" as it is making sure you buy lights that are matched to the voltage that you're planning on supplying them. You don't want to go feeding a light that's designed for 3.7v off of a 12v source.



druitre said:


> Interesting, can you explain this a bit more? What's an SLA battery? I don't have a car battery charger, is there a specific reason to use one instead of an adapter (220V AC in/12 V DC out) like the harddisk-one I mentioned?
> 
> And how do I know if the driver in a flashlight is good enough?
> 
> Thanks, Jasper


----------



## Mr_Light (Jul 20, 2009)

How about something like this?

Flexible Aluminum Cree Q4 3W 180-Lumen Ultra Bright Reading Lamp Light 
Price: $19.40 
http://www.dealextreme.com/details.dx/sku.26308


----------



## druitre (Jul 20, 2009)

Mr_Light said:


> How about something like this?
> http://www.dealextreme.com/details.dx/sku.26308



Interesting, thank you. It might have some heatsink problems if run for a long time, but it looks worth a try, at that price.


----------



## druitre (Jul 20, 2009)

Been doing some browsing through the Dealextreme catalogue and came up with this; a DIY-approach. Can anyone comment on if this would work?

- C6 DIY Cree LED Flashlight Full Casing/Shell with Driver Pill $10.99
http://www.dealextreme.com/details.dx/sku.15969

- 18V 5W Cree Circuit Board for Flashlights (16.8mm*5.5mm) $1.99
http://www.dealextreme.com/details.dx/sku.26110

- Cree XR-E R2 (WG) Emitter on Premium Star $6.93
http://www.dealextreme.com/details.dx/sku.15943

(and a heatsink for the XR-E; since I don't have to put batteries in the casing I figure I have lots of spare room so as to put in a rather large heatsink.)

Power this with the powersupply out of an old PC (12 V DC, 5 A).

Will this work? Is this circuit board sufficient for regulating the current coming out of my powersupply? With 5A, how many lights can I power?

Comments appreciated!


----------



## Illum (Jul 20, 2009)

:thinking:


----------



## bshanahan14rulz (Jul 20, 2009)

flashlights will put a hotspot with some different-colored and much dimmer spill around the hotspot. Is this the kind of light effect you are looking for? for more of a flood (same light, but spread out, so it will appear dimmer) try looking into aspherics or going optic-less. 

Other than perhaps this setup not providing the type of light you want, it looks fine to me


----------



## druitre (Jul 20, 2009)

bshanahan14rulz said:


> flashlights will put a hotspot with some different-colored and much dimmer spill around the hotspot. Is this the kind of light effect you are looking for? for more of a flood (same light, but spread out, so it will appear dimmer) try looking into aspherics or going optic-less.
> 
> Other than perhaps this setup not providing the type of light you want, it looks fine to me



You're right, ideally I'd want to be able to switch optics during filming - the carlco optics seem right for that sort of thing, with different focusing angles. Although it does not look as if they're made to be repeatedly attached and removed from the emitter. Are the emitters actually sensitive and easily broken through physical strain?

And by the way... so this looks fine? Great! Maybe I'll just give it a try and find out through trial and error, I can always order some spare emitters in case I mess up.


----------



## phalanx (Jul 21, 2009)

Marduke said:


> Easy, just use an AC/DC power supply that puts out the correct voltage for the light.


 
Marduke has the right idea. All you need to do is find a standard AC/DC power supply which could be as simple as a wall wart or a decent switch mode supply (like an ATX power supply). Your biggest issue would be how to get the power into the flashlight. I would probably make a plastic slug the size of the battery and run wires to the appropriate spots.



Illum said:


> uh.... using a wall wort to drive a regular based light?
> Voltage regulated AC-DC converters introduce a considerable amount of ripple and noise into the system...not to mention putting a regulator under a regulator usually means asking for trouble, but I dunno if this is the case if its an AC-DC paired with a DC-DC.


 
The concerns that Illum brought up are a non issue and misleading. Everything that has a converter in it, whether it's AC/DC or DC/DC, has ripple. So long as it is controlled and not excessive, it does not hurt the performance of a system. The front end of a properly designed converter will allways have extra capacitance to ensure the stability of the system even if there is a voltage ripple.

Also, running a regulator under a regulator is a very common practice and is far from asking for trouble. As one example, the motherboard in your computer generates multiple different voltages from its 3.3V supply (which all contain ripple). A common practice in military electronics is to generate a 28VDC bus and connect multiple point-of-load DC/DC converters to cover the voltage requirements of various components.



druitre said:


> @ Marduke and Illum: exactly, that's what I want but I'm confused about what components do I need to do it - does the stuff already in the flashlight interfere with the stuff in those power supplies?


 
The flashlight will not interfere with the power supplies. For all intents and purposes you can consider your battery and the equivalent voltage power supply the same thing. If it's current regulated by electronics, the flashlight will be expecting a certain DC voltage within a specific range. It does not care how the voltage was generated, just that it is present.

I would really look into using an old ATX power supply. If you don't have one lying around, you can purchase them for under $20 and it will be more than enough to drive multiple LED lights.

-Bill


----------



## SemperFi (Jul 22, 2009)

Great source of feedbacks rippling through from Bill's knowledge!!!:twothumbs 

This should narrow down Jasper's search to fix a workable base of Leds... 

I have since added two handy Leds in my separate Panel box between my front seats of my car which also houses a true sinus converter running at 350w that powers several USB and 12v receptacles for these day with many gadgets... that "_*drives*_" along with you....

Every time my hands goes into near proximity under the sensor, it lights up nicely for viewing esp. when its dark. i hope Jasper gets to work on his soon but don't stop here if anyone else has other options or alternatives to help suggest .. its great reading and base for knowledge to expand from the great minds illuminating here...


----------



## druitre (Jul 22, 2009)

phalanx said:


> _(edited for brevity)_ All you need to do is find a standard AC/DC power supply which could be as simple as a wall wart or a decent switch mode supply (like an ATX power supply).
> 
> The flashlight will not interfere with the power supplies. For all intents and purposes you can consider your battery and the equivalent voltage power supply the same thing.



Thanks, Bill! That sounds almost too good to be true... sure I've got an old ATX that I can use for this.

So, a plan would be to get a couple of these: 
http://www.dealextreme.com/details.dx/sku.16179
and modify them.

Question: the R2 P60 module in those flashlights contain the emitter, the heatsink and the circuit board, right? Is it possible to disassemble these modules so as to put in a bigger heatsink? Or am I too much concerned with heatproblems and will they function without problems even if left on for hours at an end?

And as I'd be removing the clicky in the tailcap and replace that with a connector bit for my external supply, will that change anything regarding the 5-mode functionality? In fact I'd prefer 1-mode (on/off), being sure that when I switch my supply 'on' it will always make my light go to maximum. Strobe and SOS would be utter nonsense anyway for what I'm going to be using them for.

Or should I, in light of these considerations, stick to my DIY separate components plan (post #14)?

Jasper


----------



## JimmyM (Jul 22, 2009)

An old computer ATX, etc power supply will give you 5V and 12V with a huge current capacity. Most, if not all, are switchable between 110 and 220V mains.
You could use any one of several LED buck drivers available to run 3 MC-Es in series on 12V input. You mentioned running them on Maximum brightness. That creates a lot of heat. Maybe just get some aluminum bar and mount 3 MC-E stars on each bar with one driver per bar. That would provide a better heatsink for running the emitters for extended periods of time.


----------



## druitre (Jul 22, 2009)

Hi Jimmy,

because I'm using them on a (miniature) filmset I want them to be securely encased yet not taking up a lot of space, with each light indepent of the other (physically as well as in terms of power on/off). Hence the flashlight encasing.

And it means they'll have to be wired in parallel to the power supply (or, in other words, I have to make a single power supply with multiple outlets, all at the same voltage, all with their own on/off switch). By the way, I'm in Europe (Netherlands) so it's 220 V mains over here.

But all that's considering single XR-E R2s... you're talking about 3 MC-Es. Which is also interesting, you'd be talking 2100 lumens where I'm diddling with 240. (!)

Guess I'd be better off sticking that kind of combo in a mini-par
http://www.starlight.com/minipar.html
but how would you collect/focus that kind of setup, without a donut in the beam?

-Jasper


----------



## phalanx (Jul 22, 2009)

druitre said:


> Thanks, Bill! That sounds almost too good to be true... sure I've got an old ATX that I can use for this.
> 
> So, a plan would be to get a couple of these:
> http://www.dealextreme.com/details.dx/sku.16179
> ...


 
I wish I could tell you how the 5 mode functionality works on that flashlight but I've never had my hands on one so I don't know. The discrete solution from your post #14 will require a little more work but it will give you a lot more flexibility in your design. For instance, the driver in the complete flashlight has a max input of 8.something volts which would limit you to 2 emitters being controlled by it assuming you can find a way to supply 8 volts. The controller in the discrete solution will take up to 18V which will allow you to power more LEDs off of a single unit. With the 12V ATX supply you could power 3 at the minimum and possibly 4 with a single driver (depending on the forward voltage of the LEDs).

-Bill


----------



## bshanahan14rulz (Jul 22, 2009)

most mode functionality is built into the driver. if there is a short enough break in power, the controller will cycle to the next mode.

I would stay away from different modes, however, because most cheap solutions use PWM for dimming, and this may look funny on a video camera (kind of like how CRTs look funny on video)

Hints:
Voltages add up when in series
ex: three LEDs with Vf of 3.3V are put in series. All together, they drop 9.9V.
if you want to run them at 700mA, supply the string with 700mA and each emitter will get 700mA
Power=Current*Voltage
P=0.700A*9.9V
P=6.93W

Currents add up when in parallel
ex: three LEDs with Vf of 3.3V at 700mA are put in parallel with each-other. All together, they drop 3.3V but will require 2100mA to power them all at 700mA.
P=I*V
P=2.1A*3.3V
P=6.93W


----------



## druitre (Jul 23, 2009)

@Bill: Thanks, and yeah I feel inclined towards DIY solution too, mainly because those circuit boards are so tolerant in input voltage.

@bshanahan14rulz: Thanks for the info on mode functionality, does PWM dimming come with frequency interference when shooting video? What is the frequency XRE-E LEDS are driven at, if it's possible to state it that way? My camera (Canon 5D Mark2) shoots at a fixed 30 fps, so I wouldn't want anything near 60 Hz coming from my lights.

And thanks for the hints, very useful for a non-electronics guy like me.

Regarding the circuit boards I'm considering, the specs say:

- 1*Cree 5W regulated power output
- Output current: 1A with P4 emitter; 1.2A with Q5 emitter

Does that mean 

5W / 1.2 A = 4.16V and so, if I connect my 12V powersupply to this, it will convert 7.84 V into heat and let 4.16V through to the LED? And the LED is Vf = 3.7 V so that will become really hot too?

(Excusing my kindergarten electronics )
And ehh... if I'd connect it to a MC-E, it would mean less current to each die? But it would still work?


----------



## phalanx (Jul 23, 2009)

druitre said:


> Regarding the circuit boards I'm considering, the specs say:
> 
> - 1*Cree 5W regulated power output
> - Output current: 1A with P4 emitter; 1.2A with Q5 emitter
> ...


 
I'm not sure why they list 2 different current values for different emitters. A regulated LED supply should have a fixed current output and it will vary the voltage across the LED to make that current. For the purpose of this argument, if we use your LED and assume it will be driven at a full 5W you will get this: 5W/3.7V = 1.35A. While a portion of the 5W is radiated as light, it is relatively small so you can consider the entire 5W as being dissipated as heat.

12V - 3.7V = 8.3V remaining. If you were to use a current limiting resistor instead of the regulator board you posted, then 8.3V * 1.35A = 11.2W of heat being dissipated by the resistor. In the case of your regulator board which is a DC/DC converter, it doesn't quite work this way. The converter tries to make the power coming in match the power going out. In an ideal world this would mean that your 5W LED (3.7V @1.35A) would be drawing 5W from your 12VDC supply (5W/12V = 0.42A). In the real world there are losses in the switching transistor, magnetics, and circuitry that will give you an efficiency around 90%. This means that in order to drive a 5W load, the converter will demand about 5.6W from the 12V supply (0.47A). The 0.6W difference between the input and output is dissipated as heat in the regulator circuit.

Watts Out = efficiency * Watts in
Watts in = Watts out / efficiency
Watts in = 5Wout / 0.9
Watts in = 5.6W

So when working with DC/DC converters, think "Power in = Power out" but don't forget to account for the efficiency loss in the electronics.

-Bill


----------



## bshanahan14rulz (Jul 23, 2009)

Do you have links to the boards you were thinking of using? if they are amc7135-based, you can put them in parallel for twice the current, but I'm not sure if you can put them in series. Alternatively, you could use the 5V rail instead of the 12v rail (also usually has more amperage handling, since current has an inverse relationship with voltage when power is constant)

and LEDs don't care about PWM frequency or duty cycle, they just care about on/off. It's up to the circuit designer (or what kind of controller chip is used) what the frequency and duty cycle of the PWM is. At the most basic form, you could have a 555 chip that creates the PWM signal. This signal is too weak to drive LEDs, so you'd use this signal to open/close a gate (power mosfet) to let a lot of current through. 

Dimming by varying the current would work better with cameras.


----------



## LukeA (Jul 23, 2009)

I would use a VariLED 16. You just connect the VariLED 16 to the wall and connect the LEDs to the VariLED. Put some reflectors/optics over the LEDs and you're set. It's dimmable, too.


----------



## druitre (Jul 23, 2009)

bshanahan14rulz said:


> Do you have links to the boards you were thinking of using?



See my post #14


----------

