This special purpose IEC Power Supply is designed for the "Mass Of Electron" experiment (AP2120-001). It is powered by 220/240V.Mains. The outputs are: 250V.DC. Fixed voltage, at about 1mA, 12V.AC. at about 1A, 0.1A - 2A adjustable and regulated current. The high voltage is for the anode connection of the Magic Eye tube, the 12V is for the tube's heater and the regulated current is to control the current and thus the magnetic field in the Air Cored Solenoid (EM0090-001). A switch permits the large meter to monitor either the regulated current or the output volts.