3W high power LED drive circuit diagram

The C4 capacitor is a 473 monolithic capacitor, and D3 is two 1N5819 connected in parallel.

High-power LED simple driver is the one used on high-power white lamps, but I use a 3W LED! The circuit input is 1.2V (high-capacity NI-MH battery) and the current is about 1.4 to 1.8A. The efficiency is not very high, about 70%. If you replace the 150 ohm resistor with a 200 ohm resistor, the input current will be reduced to 1.0 to 1.3A.

The D882 needs to be equipped with a small copper sheet with an area of ​​about 3 square centimeters for heat dissipation. I cut off the head of the D882 with diagonal pliers (to reduce the size), and then soldered it directly to the copper sheet.