Patent ID: 7336118
Filing Date: 2008-02-26
Classification: H02H,H02M,H03K

Abstract:
1. An inverter apparatus comprising a voltage-drive type power semiconductor switching element, a drive circuit for sending a drive signal to the control electrode of said power semiconductor switching element by using the emitter potential or the source potential of the power semiconductor switching element as a reference potential, a control circuit which uses a signal ground potential as a reference potential, and an isolated signal transmission means for converting an output signal of the control circuit that uses the signal ground potential as a reference potential into an input signal of said drive circuit that uses said switching element's emitter potential or source potential as a reference potential; wherein an abnormal signal discriminating circuit is provided between the input section of said drive circuit and said isolated signal transmission means; said abnormal signal discriminating circuit comprising a low pass filter for inputting a signal sent via said isolated signal transmission means, a band pass filter for inputting a signal sent via said isolated signal transmission means, and a switching means, wherein the output of said low pass filter is transmitted to said drive circuit via the switching means and said switching means receives an output signal of said band pass filter thereby turning on and off.