I made this dual high voltage power supply for an ion source (0-4kv) and also to bias the collector in a Faraday cup to remove secondary electrons from measurement (0-350v, typically 90v). There are 2 boost converters for the high voltage and one buck converter to power the 0-4kv boost, which is an Emco F40. It can provide 4kv @ 2ma and is connected to the MHV connector on the back panel. The Faraday Cup bias supply outputs through the BNC, and the main power connector is a 12v in through the barrel jack. There is a 10 turn potentiometer on the front panel with locking knob for precise adjustment of the high voltage.