# 3.7v lamp for E1e



## Ty_Bower (Mar 9, 2006)

I'm starting a new thread because I think there's enough difference in topic. I don't want to distract too much from the original thread. All that said, there's a lot of useful and related information in the thread concerning a 3.7v lamp for the E2 series lights:
http://candlepowerforums.com/vb/showthread.php?t=67167

I think the Strion/Stinger bulb is not a good candidate for the single celled E1e. Some have said they have run the Strion lamp off a single R123 cell, but I feel it's way over the 2C rating for the cell. I'm concerned about the safety and long term reliability of this solution. Plus, the runtime is really lousy. 

I'm trying to fit a suitable 3.7v lamp that will:

fit in the Scorpion lamp base
run off a single li-ion cell (3.7 volt)
draw no more than ~1 amp
Given a nominal capacity of 580 mAh for a typical R123 cell, this should give you at least half an hour of runtime. It's also well under the 2C discharge rate.

Here are a few of the candidates I've found from the Welch Allyn catalog. The last two should be at least as bright as the stock bulb, even after accounting for lumen losses out the front.

WA1217, 3.5v, 0.57a, 20.7 bulb lumens
WA1251, 3.5v, 0.57a, 23.9 bulb lumens
WA1216, 3.5v, 0.93a, 40.6 bulb lumens
WA1085, 3.65v, 0.98a, 50.3 bulb lumens

I checked the GE catalog, but didn't find much there. All their 5mm bulbs seem to be designed for 6 volts and up.

I also checked Carley's site. The CL1122 is probably the right size, but draws too many amps. The CL816 has the right electrical specs, but is physically too large. The 885 might work, but still needs a little too much voltage and current. It would likely be underdriven and too yellow for my liking.

Can anyone suggest other ideas? Where can I buy just a few of these Welch Allyn lamps?


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## CoffeeAchiever (Mar 22, 2006)

This is an interesting topic. I've been experimenting with Li-ion rechargeables in my SF P-Series lights and I'd like to power my new E1e with rechargeable batteries too. 

I've read the entire thread referenced above (interesting reading by the way) and it seems that the technical challenges in developing replacement lamp assemblies for E-series lights are formidable. I too would like to buy a reasonably bright (15 lumens or better) drop-in replacement for the standard SF MA01 3V lamp assembly. 

Fabricating my own bipin socket conversion from a SF MA-series assembly is beyond my abilities. If any hotwires out there would like to take on the fabrication challenge I'd be willing to help finance the bulk purchase of the bulbs. Any takers? 

Your thoughts Ty_Bower?


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## Ty_Bower (Mar 22, 2006)

Based on filament size (for tight spot) and bulb life, I think I decided the WA1085 and WA1251 might be the preferred choices (of those I've identified so far). I just don't know how to get around Welch Allyn's $250 minimum order. I'm going to need some help there.

I'm not worried about machining my own bulb socket. I've already got a couple of the Strion bases from Lighthound. I'm sure the dremel work will take a little time, but I don't expect it to be impossible. Unfortunately, I'm not interested in hand producing these in any quantity. I know Fivemega did a short run of sockets for Surefire E series lights, but it was relatively small (maybe twenty or so?). I dunno why he didn't make more. Maybe we can talk him into a second run.
http://candlepowerforums.com/vb/showthread.php?t=100914

I'm most concerned about finding a suitable bulb. I've been told the stock 3.0 volt bulb will fry instantly on a li-ion cell. I do not feel safe using the relatively high amp drawing Strion/Stinger bulb. So, I need to find something with the right voltage (3.7v) that won't draw too many amps (less than 1.0, in my opinion).

I also have concerns about the mechanical suitability of a particular bulb. I was bored, and tried stuffing a minimag bulb into the Scorpion socket. The socket is too large for this bulb, and the stress on the bulb leads broke the glass envelope. The magic gas got away, and the bulb smoked over the first time I tried to light it.So obviously, the proper fit between bulb and socket is crucial. I would expect the Streamlight bulb to fit in the Streamlight socket, but I am not as confident about the Welch Allyn bulbs. I would hate to ruin a $10 bulb for no good reason. Can anyone tell me the lead spacing on the Strion bulb? I'll probably just go buy one myself. They aren't too expensive, and available locally around here.


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## CoffeeAchiever (Mar 22, 2006)

Based on the enormous popularity of SureFire's E-series flashlights, I'm very surprised that there appear to be no 3rd party manufactures of compatible lamp assemblies for these lights. You would think that someone would have come up with a rechargeable Li-ion compatible substitute for the SF MA01, MA02 and MA03 lamps. 

I haven't researched Welch Allyn's lamp specs myself. Do you know both the maximum voltage and current draw of the WA1085 and WA1251 bulbs? Does Welch Allyn specify the safe operating voltage range for these two bulbs? Streamlight's Strion bulb could be a good candidate too. A bipin lamp would be cheaper to replace than an integrated lamp assembly. 

Once a suitable 3.7V lamp is identified it may be possible to commission a run of SF E-compatible replacement lamp assemblies from one of the specialty fabricators on this forum. I suspect that there may be enough demand on this forum alone for the final product to cover the manufacturing and components cost of a few hundred rechargeable Li-ion compatible SF E-series replacement lamp assemblies. Fivemega could probably provide some insight into the challenges involved in manufacturing a moderate run of these lamp assemblies.


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## Ty_Bower (Mar 23, 2006)

Here's the specs on the Welch Allyn lamps:
http://www.walamp.com/lpd/webstore/detail.tpl?partnumber=01251-U
http://www.walamp.com/lpd/webstore/detail.tpl?partnumber=01085-U

They don't really give a "safe" operating voltage range. These lamps are spec'd at a particular voltage. Running them at a higher voltage will give more light and whiter light, at the expense of bulb life. Either of these bulbs should give plenty of life when driven off a single li-ion cell.

The Strion bulb is a good candidate for the E2e with a 17670 cell, but draws too many amps (IMO) for the E1e with a R123 cell.


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## chevrofreak (Mar 23, 2006)

The Strion bulb does draw under 1 amp from an R123. That is under 1.5c for a 700mAh cell.


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## CoffeeAchiever (Mar 23, 2006)

Thanks for posting the spec for the Welch Allyn lamps Ty. I'm no expert but based on these bulb's fill gas (Halogen-Krypton), corrected color temperature (3,120K for the WA1251 and 3,240K for the WA1085) and rated lumens ( 23.87 and 50.26 respectively) they are not going to compete with SureFire's MA-series lamps in brightness or color. At best the WA1251 will probably look like an AA Minimag bulb and the WA1085 like a 3-C Maglite. 

The Streamlight Strion bulb would probably be a better lamp choice even though it's current draw is on the high end of the target range. In order to use the a Strion bulb as a SF MA01 rechargeable substitute, perhaps a small resistor could be used to reduce the lamp assembly's current draw. This might work with a single RCR123a protected battery.


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## David_Web (Dec 9, 2006)

Bumping this thread =)

How about a PWM dimmer?
3.7V --> 3V should not be a big problem.
At 1000 Hz I don't think the bulb or the battery would care.

Maybe someone that has experience could look at it.
I believe the FluPic board it pretty thin so that should not be a problem ether.
And it would be fully regulated to boot.


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## Outdoors Fanatic (Dec 9, 2006)

Great thread!

I've been pulling my hair out, trying to figure out how to use rechargeables in the Surefire E- series. It looks like no one cares, not even CPFers and 3rd party manufacturers. Most people are ignoring the huge commercial potential this solution would have in this market.

It seems like I need to go and fabricate my own goddamned solution...


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## Ty_Bower (Dec 9, 2006)

David_Web said:


> How about a PWM dimmer?
> 3.7V --> 3V should not be a big problem.


Fantastic idea. Almost like a baby A2. Who here can make it happen?


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## frisco (Dec 9, 2006)

I have a E1L modded by Cmacclel. FluPic with some high bin emitter, reflector and glass. This light is plain "Awesome"

My thought is why not try to mod a E1E with a direct drive LED running on a 3.7 volt rechargable??? Won't be regulated...... but your incan bulbs wouldn't either. 

Just a thought.

frisco


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## schiesz (Dec 9, 2006)

I think that an LED mod is the way to go here. Just watching any LuxIII smoke the MN01 definately points you in this direction. Unfortunately, its not THAT easy to go Lux or Cree in the Exe head. 

schiesz


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## Ty_Bower (Dec 9, 2006)

But I don't want an LED in my E1e. If I did, I would have bought an E1L in the first place. Sometimes I like a nice little incandescent. There's something pleasing about the light. And quite frankly, the Minimags and Mag Solitaires just aren't as good as an E1e. I just wish I could run it off a rechargeable cell.


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## Bryan (Dec 9, 2006)

So is there not a solution to this? I have an E1E and would like to increase the output with an R123A if possible. Money is not really a concern as long as the product works! Anyone have any ideas?


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## schiesz (Dec 10, 2006)

Ok, well what are people's results with the fivemega socket and strion bulb?  I've heard that the Strion is too much for one RCR123, but some people have some luck with it. I used to have one in an E2d and a 17670, and it beat the mn03 bulb. A strion bulb in this thing would rock!

Anybody try it? What brand of RCR123 did you use if it worked?

schiesz


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## Bryan (Dec 10, 2006)

schiesz said:


> Ok, well what are people's results with the fivemega socket and strion bulb? I've heard that the Strion is too much for one RCR123, but some people have some luck with it. I used to have one in an E2d and a 17670, and it beat the mn03 bulb. A strion bulb in this thing would rock!
> 
> Anybody try it? What brand of RCR123 did you use if it worked?
> 
> schiesz


 
How would we use that bulb? Where do we get the socket?


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## schiesz (Dec 10, 2006)

Bryan said:


> How would we use that bulb? Where do we get the socket?


 
https://www.candlepowerforums.com/threads/116870&page=1


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## Ty_Bower (Dec 10, 2006)

Bryan said:


> How would we use that bulb? Where do we get the socket?


Fivemega used to sell modified Scorpion sockets. His thread is here, but the sale is long since closed.

You can also make the same thing yourself. Look up at the first post in this thread where I reference a project for the E2 series lights. If you're too lazy to read the whole thread, jump ahead to around post #84~#88 or so. The sockets aren't expensive, but some people don't want to spend the time with the Dremel tool to make it fit right.

Once you have the socket, just plug in a Strion lamp. Then drop the whole thing in place of the MN0x lamp assembly.


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## Bryan (Dec 10, 2006)

Thanks for the info! I'm not too handy with things like that, and I don't have a Dremmel either. If anyone has a spare one or wants to make a little cash to build me a socket, let me know.


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## gchand (Dec 10, 2006)

Regarding the low-demand Welch-Allen bulbs, Litho123 has a thread going 
here:
http://candlepowerforums.com/vb/showthread.php?t=141463

George


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## khclamps (Dec 11, 2006)

In my opinion,this specification as follows：with 4.8mm 3.6V 0.80A 44lumen is a good replacement lamp for it.If you use a cell li-ion battery(3.7 volt),its burntime lasts for more than half an hour，also with bright light.

If you want some bulb,please contact me for free.


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## Outdoors Fanatic (Dec 11, 2006)

khclamps said:


> In my opinion,this specification as follows：with 4.8mm 3.6V 0.80A 44lumen is a good replacement lamp for it.If you use a cell li-ion battery(3.7 volt),its burntime lasts for more than half an hour，also with bright light.
> 
> If you want some bulb,please contact me for free.


 Do you sell these lamps? Are they compatible with the Surefire E2 series without having to install some special bulb socket or adapter?

Thanks in advance.


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## Bryan (Dec 11, 2006)

Has anyone tried running the MN03 with a single RCR123? That might hold me over until fivemega has his sockets again!


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## bxstylez (Dec 11, 2006)

i tried it
its very yellow...
thats why i sold my e1w and mn03 lamp

i'm more into high powered lights




Bryan said:


> Has anyone tried running the MN03 with a single RCR123? That might hold me over until fivemega has his sockets again!


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## Bryan (Dec 11, 2006)

bxstylez said:


> i tried it
> its very yellow...
> thats why i sold my e1w and mn03 lamp
> 
> i'm more into high powered lights


 
Thanks for the reply! That's what I was worried about. I'll stay away from that combo then.


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## David_Web (Dec 12, 2006)

Interesting.
A quick question, will the scorpion socket fit without modification? never mind the focus or bulblength.
Or will it need trimming on the outside?

*edit*
check out AWs new thread about high current R123s, might be the answer.
http://candlepowerforums.com/vb/showthread.php?t=144427


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## schiesz (Dec 12, 2006)

Scorpion socket needs trimming around the socket and at the base for it to fit.

schiesz


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