Illuminated sword RGBW LED Driver (*****saber)!
This is the first real project I began after setting up PID, and it sat on the back burner for a while. Recently I´ve taken things back up. The idea is to put a real, super high powered LED into my light-sabre reproductions – I have one official Darth Vader model and an original from Ultrasabers. The tricky thing is that all four LEDs go in series, like this:
The idea is to dim each LED independently, but have only one current source. In this case, a synchronous buck regulator with almost no output capacitance and a very fast, quasi-hysteretic control loop. The trouble is the gate control for the top three FETs. I´m still searching for a gate driver that can run from 19V or 20V and pump the top FET properly even if the other three are all on. (That’s unlikely, but possible.)
The current source itself is easy – first a synchronous boost regulator develops the 19V, then the sync buck LED driver and the parallel dimming FETs run from the 19V. The input is two 18650 LiON cells – the ones in your laptop battery. Plenty of A-h in those!
The LED will be a Luminus Devices’ SBM-160, which can run at a max of 2A, and should be not just bright, by blindingly so. I expect my swords to shine even in the daytime!