ARC-LS rev 1 circuit boost

Anyone know how to boost ARC-LS rev 1 circuit to deliver more than 350ma to Luxeon? Maybe around 500ma or even 1000ma? Is it possible? Thanks heaps /ubbthreads/images/graemlins/smile.gif

Re: ARC-LS circuit boost

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Bernhard said:
Anyone know how to boost ARC-LS circuit to deliver more than 350ma to Luxeon? Maybe around 500ma or even 1000ma? Is it possible? Thanks heaps /ubbthreads/images/graemlins/smile.gif

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Yes, Yes, and Yes [to your questions in that order]. It is very easy. Simply change the value of the sense resistor on the circuit board. The resulting current will be 0.05/R where R is the value of the sense resistor. I believe the stock value is 0.15 ohms.

Re: ARC-LS circuit boost

Can you help me identify it? e-mail sent /ubbthreads/images/graemlins/smile.gif Thanks a lot...

Re: ARC-LS circuit boost

Bernhard: Have you managed to access the circuit board? If not, you might want to consider that the board is supposed to be potted in epoxy. Can you remove the potting without damaging the circuit?

Re: ARC-LS circuit boost

Yes I can. I just heat it carefully using heat gun, and strip the epoxy. Tested after all epoxy has been stripped, and it still work perfectly.
You have to strip the epoxy little by litle very carefully, since you can only guess the location of all component. If you happen to know where all of the component are located, your work should be easier.
Just e-mail me if you want some picture of it (to know approximate component location), since I don't know whether it is legal to post pic of the circuit board in open forum like this.

Re: ARC-LS circuit boost

Did somebody happen to have the circuit schematic? Please email me...
Thanks heaps /ubbthreads/images/graemlins/smile.gif

Re: ARC-LS circuit boost

Perhaps you could send me a picture privately? My email address is in my profile. Thanks.

Re: ARC-LS circuit boost

The original poster was inquiring about the rev 1 circuit. Wasn't that boost circuit built with discrete parts (transistors, caps resistors, etc) and an inductor? It was capable of running on a single 1.5V cell, or a 3V lithium or [email protected] pack. It was loosely voltage regulated, and so probably had no current sense resistor. It may still be capable of being tweaked, but you'd have to extract a schematic from the circuit board and experiment.

The later rev lights (from the hybrid series on up through rev 2 and beyond) had an IC based boost circuit based on a part from Linear Technologies - this circuit (shared with some boards from the sandwich shop) was current regulated and did have a sense resistor. This circuit can be adjusted for current output by changing the sense resistor.

Is my memory right?

Re: ARC-LS circuit boost

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php_44 said:
The original poster was inquiring about the rev 1 circuit. Wasn't that boost circuit built with discrete parts (transistors, caps resistors, etc) and an inductor? It was capable of running on a single 1.5V cell, or a 3V lithium or [email protected] pack. It was loosely voltage regulated, and so probably had no current sense resistor. It may still be capable of being tweaked, but you'd have to extract a schematic from the circuit board and experiment.

The later rev lights (from the hybrid series on up through rev 2 and beyond) had an IC based boost circuit based on a part from Linear Technologies - this circuit (shared with some boards from the sandwich shop) was current regulated and did have a sense resistor. This circuit can be adjusted for current output by changing the sense resistor.

Is my memory right?

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I have just looked at the rev 1 circuit. It didn't use any discrete transistors. It used two switcher ICs running in parallel. There is no way to hotrod this circuit. It is already running "balls to the wall" and is limited by the onboard current limiting of the ICs. It would be possible to reduce the output to one-half by disabling one of the two ICs.

Your memory is correct about the hybrid and up circuits. My original response in this thread was based on the assumption that the original question was about the hybrid and up designs.

Re: ARC-LS circuit boost

I've been looking at the circuit as well. Thanks for the pic. Unfortunately, it looks like php44 and Doug S are right. There is no simple way to increase the output power of this circuit.

Your best hope, if you wish to use the same body, is find something suitable from the Sandwich Shoppe and swap out the board completely. You may even be able to use a 5W LS. But keep the original board since it allows you to use a single 1.5V cell if it become necessary, something that the newer boards can't do.

Re: ARC-LS circuit boost

I wouldn't recommend boosting the Arc's anywhere above twice the nominal. The head on a 1x123 does not have the mass to properly manage the heat when run in extended periods. It's better to run a hot-rodded Arc on a 2xAA for the larger mass. As said previously, the Rev1 is potted and even if it wasn't, it's already running wide open.

CM