Brightness control unit for stage lighting lamps in kW output range - has three=phase AC mains connected to lamp or lamps via fully controlled thyristor bridge with pump capacitors as neutral line connectors

摘要

A brightness control unit for stage lighting using at least one lamp with an output in the kilowatt range has the lamp or lamps connected to the three phase AC mains via a fully controlled AC bridge. An anti-interference condenser is connected in parallel with the lamp(s). The bridge contains six thyristors and between the cathodes of three of them and the neutral is a "pump condenser", with another one between the anodes of the three other thyristors and neutral. The size of these "pump capacitors" is between ten and fifty microfarads per kW rated output. There is a choke in each of the line conductors to the control unit.