Simple constant frequency constant current load-resonantpower supplyunder variable load conditions

A power supply incorporating a load-resonant converter operating at a fixed frequency and capable of efficient operation with a constant current characteristic, independent of the load conditions, is presented. The simple resonant circuit is designed so that at one of its multiple resonant frequencies both the load current and the resonant frequency are independent of the value of the load. A power supply is designed and constructed which delivers over 1 kW to a variable load at a constant switching frequency of 82 kHz.