Streamlight Jr Luxeon circuit, fully regulated?

Those in the know, please fill me in, is the circuit constant current, or simple voltage boost? It seems fairly flat output but??

How would it react with a super low Vf luxeon? like 3v it's doing 350ma current or more?

Constant current: DD until batts fall below 3v, then super long runtimes?

Voltage regulated: big boost in output/over drive?

Also, would going to a HD increase throw?
Thanks - IH

Re: Streamlight Jr Luxeon circuit, fully regulated

Judging by a quick bench test with varible power supply, I would call it a voltage boost circuit. The current to the LED did not hold when I varied the voltage. I switched to a HD but didn't try it with the stock optic; went immediately to a reflector.

Re: Streamlight Jr Luxeon circuit, fully regulated

The optic appears to be an NX05. My star is a QY0J. Pretty nice. It makes all my Q3J's and SW0K's look purplish/reddish! Which I always thought they were.. The Y0 looks blueish/greenish a tad, but nice.

So if I were to put a LuxIII with a vF of H, it would put 700ma or more to the luxIII on fresh batteries? That would be a good hot rod mod!!! Thanks Don.

Two things that concern me, the optic cuts into the emitter casing when screwed down, and shaves a bit off each time, causing farkle that has to be wiped off again and again.

Also the heatsinking worries me. It's not that great at all from what I can tell by looking at it, just mainly a cut down star board is all that is there, yet I feel heat in the head when it's running?? So it must be transfering somehow.. even through that plastic thing??

Re: Streamlight Jr Luxeon circuit, fully regulated

The star contacts the "ground plate" beneath it and this is compressed at the edges against a shoulder in the tube, as I recall?!?!? Not a great thermal path but likely fine at the current levels the light is designed to run at.

Re: Streamlight Jr Luxeon circuit, fully regulated

ah, I see as the tube walls are at an angle.

A better method without re-doing the whole design would be to spread some Arctic Alumina grease on the backside of the star so it transfers a bit better to the "ground plate".

What do you think of my idea of a super low VF luxIII? Say it pulls 700ma at 3v, would the circuit boost the voltage even higher above that! /ubbthreads/images/graemlins/eek.gif

Re: Streamlight Jr Luxeon circuit, fully regulated

Sorry,
I won't pretend to understand the dynamics of these circuits. I would assume that the lower the Vf of the LED, the higher the resulting current but as to how much power this thing can provide? /ubbthreads/images/graemlins/icon3.gif I agree that some thermal goo would aid in the transfer of heat.

Re: Streamlight Jr Luxeon circuit, fully regulated

I measured mine at 600ma current draw on both "dead" and "fresh" NiMH. So it pulls same amount of power from the batteries the whole time. But on fresh cells it was a lot brighter. So this is not constant current.

I still haven't switched to HD, as I fear cutting a new star would not end up centered right, and I've cut stars in the past and they ended up shorting out on the aluminum back... /ubbthreads/images/graemlins/icon15.gif

I do have a nice low H Vf pure white HD though that I should put in here...