The challenge I'm facing right now with this LED PCB is that it will only run on 42-48V minimum. Instead I'd rather have it operating from a 24 or 30VDC power supply. This because the step-down buck converter I intend to use (to supply the Arduino Uno with 9V) and MOSFET module (to switch the lights), only take a 36V input at max. Anything higher means trouble.
I took some voltage measurements per 8 LED string of each color:
- Red: 14.8V
- Yellow: 15.3V
- Green: 23.7V
The green LEDs are the limiting factor. It looks like a 24V running might be achievable (red and yellow are both fine with that), but the 23.7V needed for the greens worries me a bit.. Would a 24V power supply be too close for comfort here?
To achieve a 24-30V running of this LED PCB I'll need to de-solder all resistors from the board and replace them with a lower value corresponding to a determined lower input voltage. Luckily everything is well accessible. Are there any other things I have to watch out for (or take into account) when attempting this conversion? The rectifiers and Zener diodes won't mind this I guess?
Eye candy:
