Patent ID: 6021058
Filing Date: 2000-02-01
Classification: H02M

Abstract:
A PWM inverter output circuit comprising:a main dc power source;a power circuit havinga first power element comprising a first control electrode and a first reference electrode, said first power element being conductive when a positive voltage with respect to the first reference electrode is applied to the first control electrode, anda second power element comprising a second control electrode and a second reference electrode, said second power element being conductive when a negative voltage with respect to the second reference electrode is applied to the second control electrode, said first and second reference electrodes being connected together, and said first and second control electrodes being connected together;a control power source;a power supply capacitor being charged by an output voltage of the control power source;an input signal processor for receiving a command signal which controls turning on and off said power elements and for producing a predetermined plurality of logic signals; anda predrive circuit having:a state detection circuit for detecting a requested control state from a combination of said plurality of logic signals outputted from the input signal processor,a latch circuit for holding said requested control state detected by the state detection circuit,a first output driver comprising a pair of switching elements serially connected between terminals of the power supply capacitor for controlling a voltage applied to said first and second control electrodes, anda second output driver comprising a pair of switching elements serially connected between terminals of the power supply capacitor for controlling a voltage applied to said first and second reference electrodes,said first and second output drivers driving said power circuit using the power supply capacitor as a power source by controlling turning on and off said switching elements based on said requested control state held by the latch circuit to control a voltage between said first control electrode and said first reference electrode and a voltage between said second control electrode and said second reference electrode.