# Fenix E01 unpotted & driver efficiency data



## chimo (May 5, 2008)

I received my two HA Nat Fenix E01s today. I have not dissambled a head (yet), but I measured the power going in to them and the voltage to the LED when in regulation.

Here is the data:


```
Head #1			Head #2		
Vin(V)	Iin(mA)	Pin(mW)	Vin(V)	Iin(mA)	Pin(mW)
1.7	65.0	110.5	1.7	81.2	138.0
1.6	67.8	108.5	1.6	87.4	139.8
1.5	69.0	103.5	1.5	88.4	132.6
1.4	73.5	102.9	1.4	93.0	130.2
1.3	77.2	100.4	1.3	96.8	125.8
1.2	79.8	95.8	1.2	102.9	123.5
1.1	84.4	92.8	1.1	108.5	119.4
1.0	92.2	92.2	1.0	123.0	123.0
0.9	59.5	53.6	0.9	72.3	65.1
0.8	26.3	21.0	0.8	25.3	20.2
0.7	19.6	13.7	0.7	19.1	13.4
0.6	17.5	10.5	0.6	17.0	10.2
0.5	14.9	7.5	0.5	14.7	7.4
0.4	11.8	4.7	0.4	11.7	4.7
0.3	8.4	2.5	0.3	8.5	2.6
0.2	5.2	1.0	0.2	5.2	1.0
0.1	2.3	0.2	0.1	2.3	0.2
```

It appears the head drops out of regulation at around 1V. 

The voltage measured at both LEDs when in regulation was 3.2V (constant voltage regulation perhaps).

The minimum start up voltage was approx 0.3V ---> WOW!

A constant voltage regulation scheme would explain the different Power In figures above and the different run-times being measured.


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## paulr (May 6, 2008)

*Re: Partial Fenix E01 driver data*

Good measurements, thanks for making them. LED current is very sensitive to the junction voltage. Do you think it changes with temperature? It might be interesting to stick the E01 in the fridge or freezer for a while, then make another measurement.


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## chimo (May 6, 2008)

*Re: Partial Fenix E01 driver data*



paulr said:


> Good measurements, thanks for making them. LED current is very sensitive to the junction voltage. Do you think it changes with temperature? It might be interesting to stick the E01 in the fridge or freezer for a while, then make another measurement.



Absolutely. If the driver is CV, the current should go up a little as the die heats up. Since these LEDs don't seem to be badly over-driven, the temp rise should not bee too great. If the driver is 75-85% efficient, the LEDs in my E01s are driven in the range 70-118mW. The max spec sheet power dissipation for these LEDs is 105mW, however, we know that some other similar lights blow that figure out of the water. If I had to make a swag at emitter currents, I would say between 25-30mA.

The one concern I have for this light is the long-term reliability of the board ground contact. It relies on a ridge in the body tube to contact the PCB. My concern is the PCB traces wearing through due to frequent use. For most people and usage, this situation may never occur. For others, it could happen within several months or a year. Unfortunately, problems of this nature usually get greatly blown out of proportion. Fortunately, a fix is fairly easy (just solder a new contact layer to bridge the trace cuts). I will watch this one.


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## chimo (May 6, 2008)

*Re: Partial Fenix E01 driver data*

Here are some "what if" calculations. 

I measured the current through 5 bare GS and 6 bare DS LEDs when driven at 3.2V. I plugged these numbers into Excel to derive some possible efficiencies. If I were to use my small GS sample set to form conclusions, I would ballpark converter efficiency to be around 50-75% efficient (I will have to crack one open to be more exact). I will recant my original guess at emitter current to around a 19-24mA drive level depending on Vf of LED)


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## streetmaster (May 7, 2008)

*Re: Partial Fenix E01 driver data*



chimo said:


> The one concern I have for this light is the long-term reliability of the board ground contact. It relies on a ridge in the body tube to contact the PCB. My concern is the PCB traces wearing through due to frequent use. For most people and usage, this situation may never occur. For others, it could happen within several months or a year. Unfortunately, problems of this nature usually get greatly blown out of proportion. Fortunately, a fix is fairly easy (just solder a new contact layer to bridge the trace cuts). I will watch this one.


 I am worried about this too. I noticed wear on the contacts after a day of playing with the light. I think Fenix should have made the contacts a bit thicker. The ledge inside the body where the head makes contact is too abrasive in my opinion. I think this issue will haunt them in the near future. Not everyone who bought these lights has a soldering iron to fix their light when it wears out prematurely. This is one of the very few flaws I can find in the E01, at least with the two I own. I think I got lucky as far as the LED color and brightness. Both of mine came from the first batch. I got a third one for my Dad, which came from the second batch from Fenix, and it was totally blue-ish(not just the hot spot) and not as bright as mine. I don't know if this was due to being from the second batch, or just the (bad)luck of the LED lottery.


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## Moat (May 7, 2008)

*Re: Partial Fenix E01 driver data*

Nice info, Chimo! :thumbsup:

I wonder if it would be possible to polish smooth the battery tube's negative contact ridge, in order to minimize the wear on the board's contact. I've done that on some E0's (much easier than the E01, it appears), and they seem to be holding up fine with regular use, so far (about a year).

Am I reading correctly that the *DS* LED's you tested @ 3.2V, are passing between 41-48 mA?? That's pretty amazing... wouldn't that be a (@ spec 20 mA) Vf of around 3.0V? I thought the data sheet lists the *DS* as 3.6 Vf (and the *GS* as 3.2V - which looks very close to what you got) ...?? Kinda the opposite of what I'd expect, IOW - thinking the DS @ 3.2V would only be passing maybe 8-10ish mA.

:thinking: Very efficient, if so!


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## Curious_character (May 7, 2008)

*Re: Partial Fenix E01 driver data*



chimo said:


> I received my two HA Nat Fenix E01s today. I have not dissambled a head (yet), but I measured the power going in to them and the voltage to the LED when in regulation.
> 
> Here is the data:
> 
> ...


If you try regulating the voltage of an LED, you'll have large differences of current from one LED to the next or from one slightly different regulator voltage to the next. You can also get quite a large increase in current as the LED heats up. These are because the current is an exponential function of the voltage across an LED -- tiny differences in voltage result in large variations of current. So any good regulator for an LED (which I'm sure the Fenix is) is a constant current regulator. Even moderate changes in current for one reason or another will cause very little change in the LED voltage. And because of the relatively constant LED voltage, a constant current regulator delivers very nearly constant power to the LED. Your measurements are consistent with a constant current regulator which has approximately the same efficiency over the operating range of 1.0 - 1.7 volts.

c_c


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## chimo (May 7, 2008)

*Re: Partial Fenix E01 driver data*



Moat said:


> Nice info, Chimo! :thumbsup:
> 
> I wonder if it would be possible to polish smooth the battery tube's negative contact ridge, in order to minimize the wear on the board's contact. I've done that on some E0's (much easier than the E01, it appears), and they seem to be holding up fine with regular use, so far (about a year).
> 
> ...



Yes, the DS currents are for a 3.2V drive voltage. I was a little surprised at the differences.


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## chimo (May 7, 2008)

*Re: Partial Fenix E01 driver data*



Curious_character said:


> If you try regulating the voltage of an LED, you'll have large differences of current from one LED to the next or from one slightly different regulator voltage to the next. You can also get quite a large increase in current as the LED heats up. These are because the current is an exponential function of the voltage across an LED -- tiny differences in voltage result in large variations of current. So any good regulator for an LED (which I'm sure the Fenix is) is a constant current regulator. Even moderate changes in current for one reason or another will cause very little change in the LED voltage. And because of the relatively constant LED voltage, a constant current regulator delivers very nearly constant power to the LED. Your measurements are consistent with a constant current regulator which has approximately the same efficiency over the operating range of 1.0 - 1.7 volts.
> 
> c_c



Thanks cc, I'm aware of the V-I properties of LEDs and the subsequent drop in Vf as the die temperature rises and have preached the same thing many times over. It is good, however, to remind people regularly of this.

However, I am not as sure as you that the E01 uses a current regulation scheme. Do you have any additional details to share with us? 

There have been several runtime plots done now for the E01 (thanks TIN). They show fairly flat regulation with very little initial output drop. 

In my experience, with CC regulation, there is ususlly an initial drop in output (usually within the first few minutes until the die temp reaches a steady state). With CV regulation, as the die temp increases but the current will also raise slightly which should help increase output to account for the drop due to the increase in die temp. Now this all relies on reaching a steady state and the cct not going into thermal runaway. These are driven at fairly mild levels.

Did I mention that both my E01 heads have a LED drive voltage of 3.2V? The LED is soldered thru-hole so it can be measured from the bottom of the driver board.

I am not conclusively convinced either way that the E01 uses CV or CC. It will take cracking open and depotting an E01 head, doing some additional measurements and perhaps some reverse engineering to be certain. Cheers,

Paul


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## streetmaster (May 7, 2008)

*Re: Partial Fenix E01 driver data*

So, when are you gonna crack one open?(I don't mean a beer, although that sounds good)  I would give it a try, but there would be no sense in me doing it because I wouldn't know what to do with it once it was open.


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## chimo (May 7, 2008)

*Re: Partial Fenix E01 driver data*



streetmaster said:


> So, when are you gonna crack one open?(I don't mean a beer, although that sounds good)  I would give it a try, but there would be no sense in me doing it because I wouldn't know what to do with it once it was open.



As soon as that "new light smell" wears off. 

I have to go out of town on business next week and I doubt I'll get time this weekend, so it will be a while.


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## chimo (May 8, 2008)

*Re: Partial Fenix E01 driver data*

Well, that new light smell didn't last too long.  I heated one of the heads up, pushed out the pill and unpotted it. I took some pics and made some measurements. The LED is getting 25.22 mA. The efficiency was approx 78% with a fresh alkaline - pretty darn good. My wife is using the computer I normally post from so I will post the pics later.


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## chimo (May 8, 2008)

*Re: Fenix E01 opened up & Driver data*

Here are the pics.

The pill





The driver





Inside the head. Note the LED o-ring groove.





Other data:
Resistor in series w/ LED is: 1% 2ohm
Drive current: 25.22mA
Boost freq: 79kHz
No mark on the inductor
Switcher IC top mark is: 3033
Schottky top mark is: SJ
Ceramic cap is under my thumb


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## warlord (May 9, 2008)

*Re: Fenix E01 opened up & Driver data*



chimo said:


> Here are the pics.
> 
> Other data:
> Resistor in series w/ LED is: 1% 2ohm
> ...



Interesting. The spec sheet for the led shows the luminous intensity as 31,000-44,000mcd @ 20mA so at 25mA it should be brighter than spec.

Also I'm noticing that the driver seems to have the same components as the E0 but I can't confirm this since I don't have one in front of me and the search function is disabled. Can you point out any differences?

I'm tempted to disassemble mine when it arrives and extend the LED out a bit further probably with a new GS led. Will the o-ring allow the LED to protrude much further?

Thanks for sharing the info and the pics :goodjob:


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## chimo (May 9, 2008)

*Re: Fenix E01 opened up & Driver data*



warlord said:


> Interesting. The spec sheet for the led shows the luminous intensity as 31,000-44,000mcd @ 20mA so at 25mA it should be brighter than spec.
> 
> Also I'm noticing that the driver seems to have the same components as the E0 but I can't confirm this since I don't have one in front of me and the search function is disabled. Can you point out any differences?
> 
> ...



Unfortunately I don't have an E0 so I don't know about any differences.

I was concerned at first about the LED being too reset, however, I now believe that Fenix may have the LED ideally positioned to redirect the lateral tip radiation to the front off of the reflector. I find the beam of the E01 more resembles a high-power reflectored LED. There is a hotspot and a gradual drop-off of output. With my Arcs, I get output ring bands. This makes items in the darker bands much harder to see.

I'm not sure if the head will allow the LED to be sunken much deeper without a little modification. There is a fair distance from the land on the inside of the head to the beginning of the taper of the reflector.


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## Blue72 (May 9, 2008)

*Re: Fenix E01 opened up & driver data*

What did you use to heat up the head?

Also, How did you unpotted the head?


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## chimo (May 9, 2008)

*Re: Fenix E01 unpotted & driver data*



dd61999 said:


> What did you use to heat up the head?
> 
> Also, How did you unpotted the head?



I used a heatgun to warm the head and slid the pill out by pushing on the LED.

I used the same heatgun (carefully) and a dental pick to unpot the pill.

Check my thread on unpotting a new ArcAAA for more details on the method.


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## jirik_cz (May 10, 2008)

*Re: Fenix E01 unpotted & driver data*

Great work Chimo :thumbsup: Please can you measure efficiency from zero to 1.7V input voltage? Thanks.


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## chimo (May 10, 2008)

*Re: Fenix E01 unpotted & driver data*



jirik_cz said:


> Great work Chimo :thumbsup: Please can you measure efficiency from zero to 1.7V input voltage? Thanks.



I'll be out of town on a business trip next week. I should be able to get to it after I get back. The light is re-assembled but I left it unpotted.


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## Burgess (May 10, 2008)

*Re: Fenix E01 unpotted & driver data*

to Chimo --


Thank you for your time and effort 
in bringing us this information.

:twothumbs
_


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## Moat (May 11, 2008)

*Re: Fenix E01 opened up & Driver data*



warlord said:


> Also I'm noticing that the driver seems to have the same components as the E0 but I can't confirm this since I don't have one in front of me and the search function is disabled. Can you point out any differences?



FWIW - I just looked at one of my E0's -

Switcher IC is marked 303*6 *(vs. Chimo's E01's 303*3*)

Diode looks the same - marked SJ

Resistor is numbered 120, and measured 13.1 Ohm (in circuit... so not sure what that's worth).

No markings on Cap.

Great pics, Chimo. :thumbsup:

25mA seems like a good choice of drive level (compromise between efficiency/longevity/output). The same as what I measured on a stock E0, IIRC.


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## chimo (May 11, 2008)

*Re: Fenix E01 unpotted & driver data*

Thanks guys.

Moat, that's good info. Looks like the last digit is part of the date code of the IC. 

Paul


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## ViReN (May 11, 2008)

*Re: Fenix E01 unpotted & driver data*

Great Work Chimo :thumbsup:


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## greenLED (May 11, 2008)

*Re: Fenix E01 opened up & Driver data*



chimo said:


> Other data:
> Resistor in series w/ LED is: 1% 2ohm
> Drive current: 25.22mA


Could one tweak that resistor _à la Zetex_, increase the current, and use the circuit for a Lux mod of some sort?


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## chimo (May 11, 2008)

*Re: Fenix E01 opened up & Driver data*



greenLED said:


> Could one tweak that resistor _à la Zetex_, increase the current, and use the circuit for a Lux mod of some sort?



Mig, I haven't had the time to do any more analysis yet. Instead of toiling in the shop, my wife and I went on a nice bike ride today (~65-70km). Hopefully, I'll have more time next weekend. 

Seeing how the E0 mentioned above had a different value set resistor, it may be possible to get a little more range out of these converters, however, I would not get my hopes up for Lux level currents.

Paul


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## Curious_character (May 12, 2008)

*Re: Fenix E01 unpotted & driver data*

A current regulator (which I'm sure this regulator is) generally has a resistor in series with the LED to sense the current. The regulator keeps the resistor, and therefore also the LED, current constant by forcing the voltage across the resistor to be constant. So everything else being equal, the current is inversely proportional to the resistor value and you can change the current over some range by changing the resistor value. There are, of course, a number of factors which impose a limit on how high you can raise the current without causing a problem. Besides the limitations of the LED itself, increased current causes some of the electronic components to dissipate more power and potentially overheat, and at some point the inductor core could saturate which causes a dramatic change in regulator circuit operation.

c_c


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## lightemittingdiode (May 14, 2008)

*Re: Fenix E01 unpotted & driver data*

Nice work!

What led would you recommend in green color to swap out?
Tx.


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## chimo (May 15, 2008)

*Re: Fenix E01 unpotted & driver data*



lightemittingdiode said:


> Nice work!
> 
> What led would you recommend in green color to swap out?
> Tx.



The only recommendation I would have for you it that it's hard to go wrong with Nichias. You may want to start a new thread in the LED section with that question to get recommendations.


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## this_is_nascar (May 15, 2008)

*Re: Fenix E01 unpotted & driver data*

Although I don't fully understand all the techy-talk stuff, this is some really slick stuff. Thanks for posting this. I guess it won't be too long now before we see the first LED replacement in one of these.


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## greenLED (May 15, 2008)

*Re: Fenix E01 unpotted & driver data*

:thanks: Paul!


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## e2x2e (May 15, 2008)

*Re: Fenix E01 unpotted & driver data*

Great pictures. I was going to ask about how the LED was sealed against water, and then I scrolled down one more picture and you answered my question. Nice job reading my mind:tinfoilI actually used the tinfoil hat!!).

Now...put a red LED in there and I'll pay hundreds. Well, I'm just joking about that...kinda


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## koala (May 15, 2008)

*Re: Fenix E01 unpotted & driver data*

Hey so I assumed that you figured out the boost chip  ?



chimo said:


> Thanks guys.
> 
> Moat, that's good info. Looks like the last digit is part of the date code of the IC.
> 
> Paul


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## chimo (May 15, 2008)

*Re: Fenix E01 unpotted & driver data*



koala said:


> Hey so I assumed that you figured out the boost chip  ?



I'm still on the road. I'll be back home tomorrow evening but my wife has my weekend lined up for me.


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## chimo (May 17, 2008)

*Re: Fenix E01 unpotted & driver data*

I found a little time and did some more testing on the E01 head. I ran a voltage in sweep from 2V down to 0.2V. 

Test configuration (for the Fenix Data)
I used a 1% 0.05 ohm resistor in series with the LED to measure current.
Vout was measured across the LED and the 0.05 ohm resistor.
Vin was measured going into the driver board.
Previously measured ArcAAA data was used.

Keep in mind that the sample size is 1. 

Here is an Efficiency comparison of the Fenix E01 and ArcAAA.






Power In/Out comparison





Current In/Out comparison


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## paulr (May 17, 2008)

*Re: Fenix E01 unpotted & driver data*

Wow, that Arc AAA is doing a lot worse than tests of a few years ago. Is the circuit different?


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## chimo (May 18, 2008)

*Re: Fenix E01 unpotted & driver data*



paulr said:


> Wow, that Arc AAA is doing a lot worse than tests of a few years ago. Is the circuit different?



This was one of the new heads (current version) that I unpotted. (Also note my comment on sample size above.)


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## jirik_cz (May 18, 2008)

*Re: Fenix E01 unpotted & driver data*

Great job!


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## chimo (May 19, 2008)

Thanks for the kind words.

One more comment on the circuit. Unless the switcher chip uses an internal current sensing scheme, this light does use a constant-voltage (CV) regulation scheme and not constant-current (CC). 

Why? The 2 ohm resistor in series with the LED does not provide feedback to the switcher chip. If the cct is CV, then that would add a lot of work for Fenix if they wanted to try to keep the output within a certain range. This method would work OK as long as the GS LEDs were fairly close for voltage binning.


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## ViReN (May 19, 2008)

chimo said:


> Thanks for the kind words.
> 
> One more comment on the circuit. Unless the switcher chip uses an internal current sensing scheme, this light does use a constant-voltage (CV) regulation scheme and not constant-current (CC).
> 
> Why? The 2 ohm resistor in series with the LED does not provide feedback to the switcher chip. If the cct is CV, then that would add a lot of work for Fenix if they wanted to try to keep the output within a certain range. This method would work OK as long as the GS LEDs were fairly close for voltage binning.



Great info Paul. Even with the single sample size, the CV seems to work well. I think, if we have more sample size (of GS LED and / or driver) to verify how well across the range would be great.

One question, if you have other Nichia LED's (like Nichia DS/CS or Cree R2/Q5), would it be a good idea to do tests for other LED's with E01 drive circuit?


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## chimo (May 19, 2008)

ViReN said:


> One question, if you have other Nichia LED's (like Nichia DS/CS or Cree R2/Q5), would it be a good idea to do tests for other LED's with E01 drive circuit?



You read my mind. I was thinking about trying a DS LED to check the current.


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## paulr (May 19, 2008)

Chimo this is great work you're doing. I'd guess it's possible to adjust the current by changing that resistor.


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## chimo (May 19, 2008)

Thanks again folks,

*I just tried one of my DS LEDs to replace the GS. * 

*The output current jumped to 46.8mA and the output voltage remained constant at 3.2V. * 

_I guess that puts a fork in the CV/CC debate_. 

Here is a photo of the board w/o the LED. I backlit the board so you can see the pcb traces. The +/- at the top are the LED solder points. You can see that the output resistor (labelled 30Y) does not provide feedback to the switcher chip. 






In my opinion, using a CV driver in _this type of light _is perfectly acceptable as long as the current is kept reasonable to ensure the LED does not go into thermal runaway. A big well done to Fenix for doing this at such a reasonable price! 

Modding this light, however, will require some additional work in determining the required resistor to ensure the above criteria is met for the chosen replacement LED. It will require determining the replacement LED's Vf at the desired current and then calculating the voltage drop required from 3.2V and calculating the required resistance. 

Paul


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## mighty82 (May 19, 2008)

I have been trying to tell people the circuit is "cv" a long time. Finally someone can prove it.


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## koala (May 19, 2008)

I have a feeling that markings on the chip relates to the output voltage?

3033 = 3.3v
3036 = 3.6v


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## chimo (May 19, 2008)

koala said:


> I have a feeling that markings on the chip relates to the output voltage?
> 
> 3033 = 3.3v
> 3036 = 3.6v



It's hard to say. Usually some character(s) in the top mark indicate a data code. There could also be some markings on the underside of the chip. I was getting 3.2V out.

Paul


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## chimo (May 20, 2008)

I just did an LED swap for one of my E01s. 

I put in a DS LED with a lower Vf than the GS. The LED current for the particular DS I put in is 46mA at 3.2V. Input current is almost doubled so runtime will be commensurately shorter.

The internal LED o-ring still seems to seal around the slightly more tapered DS LED.

*One more observation:* 
I did not know if I liked how far Fenix set the LED back at first. After a bit of use, I think Fenix got the placement just right. The beam pattern of the E01 more closely resembles a high powered LED (hot spot with diminishing spill) than other 5mm LED lights that are very "ringy". I find the smooth, diminishing spill less distracting than the ringy beams and objects in the spill area are easier to distinguish.


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## paulr (May 20, 2008)

Does the ringiness come from the GS led or its placement? My Arc AAA-GS beam is much ringier than the AAA-CS but I figured that was because of the further-forward led placement. The AAA-CS led is recessed quite far back, and the spill is wide and smooth. This_is_nascar has expressed a preference for the DS beam over the slightly brighter GS beam for this reason.


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## Crenshaw (May 20, 2008)

wow, interesting thread, into subscriptions it goes...ive been wanting to replace my E01's led with a DS too...

Crenshaw


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## chimo (May 20, 2008)

paulr said:


> Does the ringiness come from the GS led or its placement? My Arc AAA-GS beam is much ringier than the AAA-CS but I figured that was because of the further-forward led placement. The AAA-CS led is recessed quite far back, and the spill is wide and smooth. This_is_nascar has expressed a preference for the DS beam over the slightly brighter GS beam for this reason.



I think it is mainly due to placement, however, I the different tapers of the LED likely plays a part as well. LEDs with smaller "lenses" (i.e. more tapered or smaller diameter such as 3mm LEDs) should have a wider beams. Since the DS is more tapered, the end "lens" is smaller thans the GS.


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## Moat (May 21, 2008)

I've been playing around with shortening and lightly tapering a few of these GS's (installed in E0's), and the improvement in beam smoothness (lack of rings), spill, and especially tint (pure, even snow white!) has at times been remarkable. Definite loss of throw, however (oblong, violet/blue throw, that is). 

I'm convinced that the overall shape and length of these LED's is far from being optically ideal for use in simple conical reflectored lights like the E0/E01 - especially for use as close-up/task lights.

Still need to determine the optimum length and taper, when I get the time - appears to be somewhere around 8.4/8.5mm (vs. stock GS @ 9.0/9.1mm, and CS @ 8.7mm).

Please excuse my addition to OT, Chimo.


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## chimo (May 21, 2008)

Moat said:


> I've been playing around with shortening and lightly tapering a few of these GS's (installed in E0's), and the improvement in beam smoothness (lack of rings), spill, and especially tint (pure, even snow white!) has at times been remarkable. Definite loss of throw, however (oblong, violet/blue throw, that is).
> 
> I'm convinced that the overall shape and length of these LED's is far from being optically ideal for use in simple conical reflectored lights like the E0/E01 - especially for use as close-up/task lights.
> 
> ...



No problem, I look forward to seeing (and perhaps duplicating  ) your work on ideal dome shape. I wonder if there could be some benefit in a non-round shape to the dome to counter the rectangular die shape? The die sits perpendicular to the flat surface formed by the leads. 

I have seen a photo of one of these turned to a 3mm size. Not sure of beam output.


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## Illum (May 21, 2008)

*Re: Fenix E01 unpotted & driver data*



e2x2e said:


> Now...put a red LED in there and I'll pay hundreds. Well, I'm just joking about that...kinda



If someone manages to put a red [not orange] LED in one I'd buy it for around $30:thumbsup:
<Chimos got it :thanks:>
I need one for astronomy


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## paulr (May 22, 2008)

*Re: Fenix E01 unpotted & driver data*

If you want an orange or red led 1aaa light, you can get a Peak Matterhorn for something like $25 during their memorial day sale, on for the next week or so. They are nice little lights with several led colors available.


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## mighty82 (May 22, 2008)

*Re: Fenix E01 unpotted & driver data*

Do anybody know what current a cree r2 or a q5 would draw at 3.2V? (this being a constant voltage circuit). Witch of them have the lowest vf? I'm thinking about modding one into one of my E01's. Just for fun.


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## chimo (May 22, 2008)

*Re: Fenix E01 unpotted & driver data*



mighty82 said:


> Do anybody know what current a cree r2 or a q5 would draw at 3.2V? (this being a constant voltage circuit). Witch of them have the lowest vf? I'm thinking about modding one into one of my E01's. Just for fun.



In my experience, the current at 3.2V will likely be a lot more than the cct can handle. You would have to profile the specific LED you want to use to determine a current (say 50mA) and Vf and then work backwards to determine the dropping resistor. You may also want to start with a "colder" tint as you will be under-driving the Cree and the colour will shift to the warmer side.


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## paulr (May 23, 2008)

*Re: Fenix E01 unpotted & driver data*

Unless you want a wide flood beam, you'll want more of a reflector behind the Cree, or some kind of optic in front of it.


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## Tohuwabohu (Jun 10, 2008)

I made some measurements of input current and battery voltage with an USB-oscilloscope.
I used a 10 milliohm shunt to measure the current.

First I measured average off-load battery voltage Vo, then average battery voltage Vin and input current Iin of some different types of AA-size batteries (scope-setting: 2ms/div, 200k points/track, 10 MS/sec, average of 32 tracks):


```
V0(V)    Vin(V)    Iin(mA)
fresh Energizer Lithium AAA         1.80    1.71     73.8
fresh Energizer Alkaline AAA        1.59    1.55     81.7
used Varta Alkaline (1) AAA         1.28    1.05    107.3
used Varta Alkaline (2) AAA         1.10    0.86     52.5
Sanyo Eneloop AAA                   1.46    1.44     82.8
```
Then I took the following graphs at a setting of 20 microseconds/div:

fresh Energizer Lithium





fresh Energizer Alkaline





used Varta Alkaline (1)





used Varta Alkaline (2)




The voltage under laod is well below 1V. Chimo stated in the first post of this tread that the head drops out of regulation at around 1V. I think that is what can be seen here.

Sanyo Eneloop




Battery voltage shows smaller ripple than with alkaline batteries.

Just for comparison one measurement with an AA sized Eneloop:




Input current is nearly identical to AAA sized Eneloop but battery voltage shows even smaller ripple.


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## jirik_cz (Jun 10, 2008)

Great post. Thanks. :thumbsup:


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## Probedude (Jun 29, 2008)

Anyone have any info on the chip used? (manufacture, pn and datasheet?)

TIA,
Dave


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## Illum (Jun 30, 2008)




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## Tohuwabohu (Jun 30, 2008)

It is definitely not a linear regulator.
It is a step-up DC-DC converter (boost converter).

I found two that seem to be quite similar to the one used in the E01: ON Semiconductor NCP1402 and NCP1400A
But both should have a different marking.


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## chimo (Jun 30, 2008)

Tohuwabohu said:


> It is definitely not a linear regulator.
> It is a step-up DC-DC converter (boost converter).
> 
> I found two that seem to be quite similar to the one used in the E01: ON Semiconductor NCP1402 and NCP1400A
> But both should have a different marking.



It is a boost regulator (I don't know which one) but not either of these, however, if people want to do some sleuthing, the second one you have linked will be of interest to folks - take a close look at the data sheet. (Hint: it is used in a popular light)


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## Probedude (Jun 30, 2008)

chimo said:


> It is a boost regulator (I don't know which one) but not either of these, however, if people want to do some sleuthing, the second one you have linked will be of interest to folks - take a close look at the data sheet. (Hint: it is used in a popular light)



Thanks. SparkFun used the latter in a Simon type game that I bought a while back. Pretty impressive given the size of the IC and the inductor.

Now I just have to find someone that sells singles instead of full 3K reels!

Dave


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## chimo (Jul 1, 2008)

Probedude said:


> Thanks. SparkFun used the latter in a Simon type game that I bought a while back. Pretty impressive given the size of the IC and the inductor.
> 
> Now I just have to find someone that sells singles instead of full 3K reels!
> 
> Dave



You used to be able to get them in smaller qty. I believe you can still get them as samples. Cheers,

Paul


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## Probedude (Jul 1, 2008)

chimo said:


> You used to be able to get them in smaller qty. I believe you can still get them as samples. Cheers,
> 
> Paul



Yep, though OnSemi is charging a shipping and handling fee of $11.

I did find that Newark has the 3.3V and 5.0V ones in stock in singles for $0.55 each. My Newark rep is in town on Tues - I'll see if they can sample me a few or will just drop them in an envelope to save on shipping costs.


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## Fallingwater (Jul 2, 2008)

paulr said:


> Does the ringiness come from the GS led or its placement?


It's the LED.

I have a modded light (body from a 1xAA plastic supermarket incandescent, driver from the 1xAA 1x5mmLED from qualitychinagoods) in which I used a generic chinese white LED. It had a very clean, white beam, but little power.

I recently swapped in a GS; the output jumped up enough to make the light actually useful, but the beam is stupidly ringy, with blue-violet hotspot (good) and yellowish rings (bad). Some of the rings are given by the reflector - it's practically useless there since the swap, but it's an integral part of the head so I can't remove it - but most come from the LED.

Great work chimo


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## hank (Oct 29, 2009)

hmmm, anyone done anything recently with an EO1 that they can recommend?

I ask because I got the holiday deal TK20-plus-EO1 (for the TK20, obviously, and that's just what I hoped for outdoor/camping use). Happy as a clam with that.

I didn't know anything about an EO1 [EDIT, caught up, now I know the purple oval spot with yellow spill is normal. No worries.]

Having read the instructions for taking it apart with interest; I can do that with no hesitation on this light.
[EDIT -- found the several other EO1 threads; don't want to revive any of that; I see I have a typical EO1, and it can be opened up and taken apart, which I'd like to do]

Then what? (got a temp-controlled soldering iron and magnifier, but haven't yet tried taking a pill apart to replace the LED.)

Can I put in something like the SMJLED, if people are still using those? I dropped some of those into 2xAA [email protected] and liked the results; if this light can drive that, it would be fine. Or a yellow/amber LED if anything's available that would swap in, though I assume the voltage wouldn't match. Any advice on what might be workable?
Anything better I can put into this case?


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## AvPD (Nov 26, 2009)

What's the maximum input voltage the driver can handle, I was just running a Li-ion 10440 (4.09 V) but to my surprise found that it is not supported and that I could not find any mention of someone having tested one.


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## Fallingwater (Dec 28, 2011)

chimo said:


> Thanks again folks,
> 
> *I just tried one of my DS LEDs to replace the GS. *
> 
> ...


Resurrecting this thread because I have a question specifically on this. Namely: were I to connect three Nichia GS LEDs in parallel to the output of one of these drivers, would they all be driven at the same level a single GS is? From what I know about CV converters the answer should be "yes", but I'm worried that the driver could let the magic smoke out if forced to deliver three times its rated current.

Also, judging by the back of the board, this driver seems to be roughly the same as used on the Nitecore T0. Has anyone confirmed this?


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