| 摘要 |
A DC-to-AC voltage converter for the supply of power to at least one load, comprising an input circuit and at least one output circuit galvanically separated from said input circuit, and a converter transformer. According to the invention a primary winding of the converter transformer is series-connected to a switching transistor, which series circuit arrangement is connected between a positive input terminal and a negative input terminal, with one or more resonance capacitors being connected in parallel with the collector-emitter circuit of the switching transistor and/or in parallel with said primary winding. Control circuitry is provided for said switching transistor, with the resonance capacitor(s) and said primary winding being dimensioned so that, under all anticipated load conditions of the converter, including short-circuiting of the output circuits, the control causes the voltage across the collector-emitter circuit of the switching transistor, after the latter has become non-conductive, to fall back to a very low value before the switching transistor is again driven into the conductive state. The converter transformer has a first auxiliary winding strongly coupled with said primary winding and, at least in part, provides the driving power required for the switching transistor. A time-delay and turn-off circuit is energized and synchronized by at least one second auxiliary winding of the converter transformer, and a smoothing circuit provides the driving power for turning off the switching transistor, which driving power is withdrawn from a third auxiliary winding of the converter transformer. |
