| 摘要 |
An induction furnace is provided comprising a voltage source series inverter (14), a load circuit (16) having a combination of an induction coil (34) and a resonating capacitor bank (C1, C2), and control circuitry (40) to phase lock the inverter frequency to the natural resonant frequency of the load. The capacitor bank can be divided into two groups, one (C1) across the output of the inverter and the other (C2) in series with the load. This arrangement allows for the division of the inverter voltage across the furnace coil according to the ratio of the two capacitances. The inverter uses pulse width modulation and is buffered from the load circuit by means of a small series connected inductor (17). Additionally, the system can have a common power supply system that supplies power in any desired proportion to a plurality of induction furnaces.
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