This is a miniature power supply which accepts voltage inputs between 12 and 18 volts. It uses a 12 position dip switch to program the output of the power supply. The power supply can output 12v, 5v, and 3.3v. At 5v the power supply is switchable between 5mA, 10mA, 20mA, 30mA and it can also output a square wave signal of 0.1Hz, 1Hz, 10Hz, 100Hz, and 1kHz. The power supply is built with three voltage regulators and a 555 timer. It includes two LEDs indicating power output and frequency.