Power regulated light

[ENikS]

I posted description of this light in 'lights' section but I think I should mention it here too.

I’ve been on a quest for perfect backup light for a while. The criteria where:
• Small size, kind of obvious.
• Light weight; no one wants to carry 8 D cell light on every dive.
• Very bright light. It should be useful at day time as well as at night.

The burning time has to be around 70 – 120 minutes. After that I can change to a new set of batteries (I don’t do overhead).
When I came across Princeton Tec Surge I tough it was perfect except it would go deem after 20 – 30 minutes of burning. It would still be useable but for day dives it was almost useless.
To fix that I’ve added some circuitry to compensate for battery voltage drop over time. It would draw more current providing constant output power. The batteries will deplete more rapidly but light output would be constantly bright until the very end.
When battery depleted to the point where it is impossible to bust it anymore, the circuitry shuts down and lamp powers from battery directly providing another 20 or so minutes of deem light.
Additional benefit of this circuitry is that now I can use rechargeable batteries without any light output degradation. It is as bright with NiMH batteries as with alkaline, but with 2200 mAh NiMH rechargeable batteries (http://www.mahaenergy.com) I am getting better burn time then with regular Duracell.

[unfix8r]

fascinating. you just built this from scratch?

[ENikS]

fascinating. you just built this from scratch?

I have degree in Electronic Engineering so it wasn’t such a bid deal. I ordered PCB (it is chip novo days) but everything else is done by me.

[ENikS]

For those who might be interested I’m posting schematics of the regulator. It is a typical boost DC/DC converter with MAX1763 as a controller. This regulator can produce maximum of 5.5V output voltage and 1.5A of current which is sufficient to feed Surge's light bulb.

[lairdb]

For those who might be interested I’m posting schematics of the regulator. It is a typical boost DC/DC converter with MAX1763 as a controller. This regulator can produce maximum of 5.5V output voltage and 1.5A of current which is sufficient to feed Surge's light bulb.

ENikS, have you considered producing these? Would you consider producing, if even just a limited run for ScubaBoard nutcases? My resist, etch and drill days are long past (that probably begins to betray how long) and for that matter, I quit hand-soldering well before SMT, but I'd be interested in having your circuit, and it sounds as though others might be.

--Laird

[ENikS]

ENikS, have you considered producing these? Would you consider producing, if even just a limited run for ScubaBoard nutcases? My resist, etch and drill days are long past (that probably begins to betray how long) and for that matter, I quit hand-soldering well before SMT, but I'd be interested in having your circuit, and it sounds as though others might be.

--Laird

Laird,

If enought people is interested I might. I never done production of anything yet so it may be interesting experience.
The device will not be cheap, it is going to run at $15 - $30 dollars just for parts alone (Considering small quantities).
If you still interested I could probably come up with more exact numbers...

I could make one or two from parts I have so you can evaluate it but it will be even more expensive for me. It will be a custom job...

Eugene