“High-power LEDs over 1W are now quite inexpensive. I’m sure many of you are incorporating LEDs as light sources in your projects. However I realize that the finding and configuring the power supply is still not as simple as it can be; commercially available LED drivers are convenient, but often overkill or not flexible. Even my own Universal LED Driver can be overkill at times. Some projects call for a bear minimum, simple driver. So I created the “Poorman’s Buck” - simple switch-mode (buck) constant current LED driver that’s built without a microcontroller or a specialized IC. All of the parts are easy to obtain, “off-the-shelf”, though-hole parts. Even though this driver is minimalistic, I added a current adjust function that doubles as a dimmer, and an input to control the output with PWM. This makes the “Poorman’s Buck” perfect building block for Arduino or other microcontroller based LED projects - you can control many high-power LEDs from a microcontroller simply by sending PWM signal. With Arduino you can simply use “AnalogWrite()” to control the brightness of high-power LEDs.”