I created this based on another design i made to drive high powered LEDs (3V LEDs on 5V supply) without losing too much power through the resistors. Not as good as i was hoping for, but better than nothing.
Basic Step Down Converter with a Schmitt Trigger as controller driving an Array of LEDs. The resistors are mandatory to create the voltage difference required by the Trigger and to protect the LEDs in case they aren't exactly identical.
Close switch to start.
LEDs with 100 Ohm Resistors -> 0,32W lost
LEDs with 10 Ohm Resistors -> 0,032W lost
+ ~0,1W for the controlling = 0,132W
