Low-cost inverter output short-circuit protecting circuit

The utility model discloses a low-cost inverter output short-circuit protecting circuit. The protecting circuit is mainly composed of a Vce voltage signal extracting circuit, a signal comparing circuit, a power tube drive circuit and a processor. The Vce voltage signal extracting circuit makes information of a voltage difference Vce between the source electrode and the drain electrode of an IGBT or an MOSFET in an inverter transmitted to the signal comparing circuit. The signal comparing circuit is used for comparing the voltage Vce and a set voltage Vth. When the Vce is greater than the Vth, the level output by the signal comparing circuit is changed. The level change information is sent to the power tube drive circuit which blocks driving signals at once. meanwhile, as an over-current signal, the level change information is sent to the processor. After receiving the signal, the processor immediately turns off a signal source. Compared with a conventional detection scheme specially adopting a driving chip or a Hall sensor, a detection scheme adopting the above-mentioned inverter output short-circuit protecting circuit has a cost less than 30% of the conventional detection scheme cost. Therefore, the inverter output short-circuit protecting circuit has a wide application prospect.