Originally posted by ShackMan:
See, now THIS is the type of prop talk *I* like ... lights, switches, batteries. Maybe that's why I never got into sabers and blasters much. 
Just a couple of things to touch on, since I just found this thread (and may not be back for a while).
1) The circuit board shown in the helmet (assumed to be powering the range finder lights) isn't too big to house a flasher circuit. I've made them smaller based on need. But considering these guys were making something to be hidden in a helmet, I don't think they were too worried about conserving that much space.
2) Someone mentioned that 3V is enough to drive LEDs, which is true to a certain degree. If you're wanting them to flash, you may need more power. The reason being that most circuits will require 4 (or 5) volts. Also, LEDs have the circuit basically built-into the LED. All you have to do is power them up and they flash. I've never used one, so I couldn't tell you what voltage they need.
3) Regardless how you're doing your range finder lights (flashing, steady-on, etc.), be sure to use current limiting resistors in series with the LEDs. This will not only save your LEDs from burning themselves out, but could also significantly increase your battery life.
4) If buying LEDs and doing this yourself (as opposed to the flasher kit shown above), don't forget that LEDS are polarized. Diodes only work one way. So if you hook the LED up backward, everything else could be fine and you'll still never see any light.
Good luck,
ATM
Rapier wit? This is the end of the twentieth century! I'm using a laser sighted under-and-over twin barrelled wit, with a 7.62 mm floating breech pulse rifle firing caseless one-liners on top, and a 40mm explosive gag launcher underneath. For backup I've got a 14mm pump shotgun firing flechette rounds with 10 barbed comments in each, which can also shoot sabot ego-piercing rounds. Of course when all else fails, there's always the trusty flamethrower which I've strapped to my pulse rifle with duct tape in the approved style.
