HV generator incorporating multiplier circuit - has additional switched bridge to maintain output between peaks of cycle

摘要

The generator, fed by an a.c. supply (40) consists of a voltage multiplier (1) which can be switched in parallel with a rectifying bridge (9). The multiplier consists of two diodes and two capacitors while the bridge consists of four diodes. The bridge is connected to the generator output terminals (18,20) in parallel with a smoothing capacitor (22). A switch can connect the negative output terminal (20) via one diode to the junction between the first diode and capacitor of the multiplier, and via another diode to the junction between the second diode and capacitor. When the switch is closed the output voltage is equal to that across the first capacitor, when it is open, the voltage can fall, but not to a level below the output of the bridge. The switch is a semiconductor type, which is operated by a zero-crossing detector.