This is the LM555 PWM Motor Controller Kit. This is a neat circuit in a very small footprint (1.5" x 2.0") that will control a DC Motor from the range of 5% to 95%. The Motor should be a DC type and rated to less then 2 Amps. The maximum current is determined by the output Transistor which is a TIP31C. The Pulse-Width-Modulation frequency is approx 1.750KHz and can be adjusted from 5% to 95% of full voltage. The circuit will operate from 5vdc to 16vdc. It comes with a heatsink to maintain cool operation at the higher currents. Uses for this are unlimited. Instead of a Motor, it will also dim a string of LEDs and such. The PCB is double-sided, plated thru-hole, 1.5" long x 2.0" wide made of .062" FR-4 epoxy glass. With the Heatsink, the assembled PCB is 1.7" high. It has Blue Solder Mask (LPI) on both sides with white Silk Screen on the Top side. It includes 4 mounting holes.NightFire Electronics