The disclosed technology relates to a gate protection circuit for an Insulated Gate Bipolar Transistor (IGBT), the IGBT being used as a switch device in a solid state pulse modulator based on the MARX generator principle, the gate protection circuit including: a voltage regulator configured to supply a stable voltage to an emitter of the IGBT with respect to the ground for a gate of the IGBT.

A gate drive circuit includes one output element, a constant current drive circuit, and a constant voltage drive circuit. The output element outputs a gate drive signal to a gate of a gate driven switching element. The constant current drive circuit causes the output element to output the gate drive signal with a constant current. The constant voltage drive circuit causes the output element to output the gate drive signal with a constant voltage.

The disclosure relates to solid state relay circuit for switching an electrical load. The solid state relay circuit may include a relay transistor; and a driver circuit comprising a constant current source. The driver circuit is configured and arranged to switchably operate the relay transistor, and the relay transistor is configured and arranged to switchably operate the electrical load.

A serial IGBT voltage equalization method and system based on an auxiliary voltage source is disclosed. The method includes the following steps. (1) Detect a port dynamic voltage of each serial IGBT. (2) Perform dynamic overvoltage diagnosis respectively on the port dynamic voltage of each IGBT. (3) Supply emergency high level signal to the gate of the IGBT when there is dynamic overvoltage. (4) Stop supplying emergency high level signal to the gate of the IGBT, supply a constant voltage at the gate of the IGBT through the auxiliary voltage source. The invention provides a constant voltage through the auxiliary voltage source, prolongs the off time of the faulty IGBT, and turns off other IGBTs simultaneously, thereby achieving the purpose of serial IGBT voltage equalization.

A system and method for an overcurrent detector includes a device. The device includes a threshold generation circuit, and an overpower determination circuit. The threshold generation circuit is configured to produce a threshold value based on an output of a temperature sensor proximate to a power transistor, and a maximum power dissipation in the power transistor. The overpower determination circuit is configured to determine an overpower state of the power transistor based on the threshold value and a switch voltage. The switch voltage is detected between a source and a drain or a collector and an emitter of the power transistor.

A protective circuit for a semiconductor switch includes a clamp diode, an NPN bipolar transistor, a PNP bipolar transistor, a capacitor connected in parallel with the base-emitter path of the PNP bipolar transistor, and at least three resistors. The bipolar transistors are connected to a thyristor structure that is connected to the cathode of the clamp diode. A first resistor is connected in parallel with the base-emitter path of the NPN bipolar transistor. A first terminal of the second resistor is connected to the base of the PNP bipolar transistor. Either a third resistor is connected in parallel with the base-emitter path of the PNP bipolar transistor, or a first terminal of the third resistor is connected to the emitter of the PNP bipolar transistor and the second terminal of the third resistor is connected to the second terminal of the second resistor.

A system for driving an inductive load of an appliance is provided. The system includes a direct current (DC) bus of the appliance. The DC bus is coupled to the inductive load of the appliance. The system includes a transistor having a first terminal, a second terminal, and a third terminal. The first terminal is coupled to the inductive load of the appliance. The second terminal is coupled to ground. The system includes a controller coupled to the third terminal of the transistor. The controller is configured to control operation of the transistor to drive the inductive load of the appliance.

A protection circuit for a semiconductor switch has a gate that can be controlled by a gate driver. The protection circuit includes an integrator for detecting a gate charge of the gate and a comparator unit for switching off the semiconductor switch in dependence on the value of the gate charge relative to a reference charge.

A control device for a power semiconductor switch, has a first, second and third electrical control device terminal, and a control device that according to a control signal generates an actuation voltage on the third control device terminal and actuates the power semiconductor switch. An overcurrent detection circuit determines a first voltage corresponding to a primary power semiconductor switch voltage present between the first and second control device terminals and, if the first voltage, further to commence the generation of an actuation voltage for a switch-on of the power semiconductor switch, and if the voltage exceeds a reference voltage, to generate an overcurrent detection signal. A blocking circuit blocks the output of the overcurrent detection signal from the overcurrent detection circuit, if a control current flowing in the third control device terminal for the actuation of the power semiconductor switch exceeds a first current value and/or is designed to block the output of the overcurrent detection signal from the overcurrent detection circuit, if the actuation voltage is smaller than a first voltage value.

The disclosed technology relates to a gate protection circuit for an Insulated Gate Bipolar Transistor (IGBT), the IGBT being used as a switch device in a solid state pulse modulator based on the MARX generator principle, the gate protection circuit including: a voltage regulator configured to supply a stable voltage to an emitter of the IGBT with respect to the ground for a gate of the IGBT.