How does the Ramp up and down feature work on Driver Boards?

[Tekka]

i never built a a lightsaber before and was planning to build one pretty soon. Although I would love to jump head first and buy Luxeon V and the $40 Driver I think im going to start simple and use a K2 Star and a Resistor to experiment a little. I'm pretty ok at doing simple circuits and soldering but this ramp up feature just has me stumped on how it works. Is the board simply an automatic POT that adjust the power so it slowly lights up to full power or something? I have access to tons or electronic parts to use and was wondering if i can somehow make a cheaper version of this driver board for some experimentation.[/list]

[DACOTA]

Is the board simply an automatic POT that adjust the power so it slowly lights up to full power or something?

I am not sure of the pot thing but yes it just acts like a dimmer,it ramps up the brightness from dim to full brightness in a manner of seconds and the light travels down the blade and gives it a extend retract effect but not as good as an fx saber which has a string of leds in the blade that light up sequentially.This is a saber from Novastar with a sound board from plecterlabs.com http://youtube.com/watch?v=jmIrU3_H6FI ,but the corbin board has sorta the same effect.

[Marsupial]

Is the board simply an automatic POT that adjust the power so it slowly lights up to full power or something?

not at all.

if you use a potentiometer (variable resistor) you get a change in brightness, but also in light properties. Problem is, the led will look weird if powered too low. A good example of that is the cyan Luxeon III looking GREEN when underpowered.

what the driver does is a PWM - it pulses continually the power. For the ramp up and ramp down, it gives a variable cycle, in order to light up less and more, without damaging the light properties.

if you want to do it yourself, go ahead... but I myself figured that 40$ for a small-sized board profesionally made that does the job properly is actually a very decent price.

moreover, you could go for plecter labs' sound board, or the Ultrasound that's available here at TCSS... you get sound in addition to driving your LED.