I bought an LED strip but it didn't come with a power supply or dimmer and I wasn't about to splurge on dimmer switches and fancy power supplies. So I bought this PWM controller and a 12V power supply (also under $20) to power and control my LED strip. This controller appears to be very efficient and generates minimal heat for my application. While turning the potentiometer knob all the way doesn't turn it off completely, this controller has a switch on the side to turn it off completely, so it works for me. This controller should also work well for DC motor speed control.