Death of an HO-E1R bulb.

F89

Flashlight Enthusiast
Joined
Mar 15, 2014
Messages
2,046
Just had a LF 3.7V, 50 lumen bulb die after minimal use.
I inspected the bulb with a 10x loupe and couldn't see any issues, filament intact.
No continuity with a multimeter so it's definitely gone.
Is this normal?
 
I'm assuming the lamp wasn't overdriven or dropped at any point.

I've had the same thing happen before, but with automotive lamps and a few PR base flashlight bulbs. Unless you have repeated lamp failures, I wouldn't put much thought into it. Duds happen. I'd wager that is more than likely the case here.
 
F89, I feel your pain over a prematurely blown $20 lamp assembly. Enough of these experiences led me to limit my incan collection to lights that had softstart/regulation. My new ML25IT will be getting an NTC in the tailcap soon.
 
F89, I feel your pain over a prematurely blown $20 lamp assembly. Enough of these experiences led me to limit my incan collection to lights that had softstart/regulation. My new ML25IT will be getting an NTC in the tailcap soon.
I'd love some soft start and/or regulation action.
The LF lamps definitely aren't my favourite. Dud aside, the beam quality while decent is nowhere near as good as SF or the excellent Tad Customs 3712 and bi-pin adapter.
I've been running the same Tad 3712 in an E2E (on 16650) for years (not a heap of runtime on it but used for years nonetheless) and it's fantastic. Excellent beam quality.
If I knew then what I know now I'd have bought a couple more (Tad) adapters and a heap of bulbs.
I'm onto a new LF lamp now (running on 16340), I bought three so I'll see how long this one lasts.
 
Leukos, I'd be interested to see/hear more about these rigs you speak of.
Is it as straight forward as installing something like this in the switch or is there more to it than that?

IMG_8404.jpegIMG_8403.jpeg

What resistance would work best for a 3.7V bulb running off a 16340/16650?
 
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Choose an NTC between 1 and 10 Ohms (probably 1 Ohm for your setup) and check the specs to ensure the amp limit works for your setup. I'm not sure if anyone has added one to an E series tailcap since NTCs do take up some space. The ones I have installed are in larger lights such as Mags and Fultons. Here's a thread with a pic of a typical tailcap install: https://www.candlepowerforums.com/t...-start-a-standard-mag-switch.283268/?t=283268

If the NTC is too big for your tailcap, you could instead wire up a resistor that could fit an E series spring. Sorry I can't be more help, I sold off my E series lights years ago. I kept several A2s instead.
 
I'll see if I can get my hands on a small NTC thermistor of around 1ohm that can handle 5W or there about.
I like the idea of a NTC because of the soft start, less resistance as it warms up factor.

What would be the benefit of using a resistor? I imagine you wouldn't want too much resistance as you'd starve the bulb?

What I'd like to achieve, if I can, is a nice soft start that once going has minimal resistance.
Hopefully the right component specifications can strike the right balance.
Apologies if my lack of technical knowledge is making for little sense, I appreciate the advice.
 
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