Challenge: a new direction for mods.

I have been thinking about items that I would like to purchase, but I haven't seen them even mentioned on this forum.

I want a regulator for the PT Surge or any of the 6V lights using 2 CR123 batteries. It would need to run at about 6.5V and 1.25-1.5A output, with 3.5-6.0V input.

If someone could produce it, I would gladly pay for their efforts. That would open up a whole new field of modded lights.

I would buy a regulated Surge.
I would buy a regulated LX or 6P.
I would buy a double barrel, series/parallel CR123 light with any first class head on it.

If anyone is interested in tackling a project like this, please answer here or send me an email.

You might want to check out the efforts going into designing circuits for the upcoming 5W Luxeon Star from Lumileds. The input and output characteristics of the circuit are similar to what you are asking for and there is a lot of good design work going into it:

Best Chip/Step Up Circuit Design for the new 5W Luxeon Star?

- Russ

There is another way to go which is cheaper and more efficient, but to use it requires that you change your parameters a bit.

Willie Hunt's Lightbulb Voltage Regulators

These are PWM buck regulators, rather than boost regulators. This means that the battery voltage needs to be greater than the bulb voltage over the entire discharge, which often means more cells.

The benefit is that the regulation does not require high current inductors, does not require filter capacitors, and can operate at a switching frequency of 400 Hz rather than 100,000 Hz or above. The efficiency is excellent, the system can easily work at much higher power levels than flashlights usually require. Since the regulation is PIC microcontroller based, you get the benefit of things like lamp 'dim-up' and various dimming levels.

I'd suggest giving the beasties a look. I use a similar system on my bicycle headlight, and the regulation is a delight.

-Jon

r2: I have looked at the boards they are thinking about for the 5W LS. I don't think they will put out enough amps. They are only shooting for 5W and the lights I want modded are around 8W.

Johnathon: I have seen the site you reference. I want the cases of the lights to be small, so more batteries is not what I was hoping to do.

I understand the desire to keep things small, but you are asking for 12W out of a couple of CR123 cells, and I've got to say that you are asking too much (you want 10W out, and the converter/regulator will have its losses, so 12V is what you want from the cells.)

Take a look at theDuracell Ultra 123 datasheet. At a power drain of 4 watts per cell, the useable power delivered is less than 1.5 watt hours.

Now you could stay small by working with the two cells, but reducing the bulb voltage to something that you can regulate to.

Going to the lower voltage lamp probably means reduced lamp power, although this is not necessarily the case since you can always raise current. However you shouldn't underestimate the benefits to be gained from being able to operate the lamp at _exactly_ the right voltage to give the desired combination of efficiency and life. A 3W lamp operated at the proper voltage produces as much light as a 6W lamp operated at 80% of rated voltage...and to get all of the juice out of a CR123 you need to let the voltage drop down to 50% of the initial value.

-Jon

The PT Surge, the Brinkmann LX and the Surefire 6P are bright enough as is. I thought their outputs were nearly 8W. I am not trying to make them brighter, just regulate the output for nearly constant light.

I still need to know if anyone can make a regulator.