Portable power unit using a cycloconverter for generating a high power single-phase alternating current

摘要

A portable power unit has a magneto generator having three-phase output windings. A synchronizing signal is formed in synchronism with an output frequency of the magneto generator. A pair of variable control bridge circuits are connected to the three-phase output windings and connected in antiparallel connection to each other to form a cycloconverter for generating a single-phase alternating current having a desired frequency to be supplied to a load. A bridge drive circuit is responsive to the synchronizing signal from the synchronizing signal-forming circuit, for causing the pair of variable control bridge circuits to be alternately switched to operate every half a repetition period of the single-phase alternating current, to thereby cause the cycloconverter to generate the single-phase alternating current. An output voltage-detecting circuit detects an output voltage of the pair of variable control bridge circuits. An output voltage-adjusting circuit compares the output voltage detected by the output voltage-detecting circuit with a desired voltage to thereby control the bridge drive circuit in a manner such that the output voltage of the pair of variable control bridge circuits is maintained substantially at a fixed value.