Disclosed is an electronic circuit. The electronic circuit includes a first transistor device and a clamping circuit. The first transistor device includes a control node and a load path between a first load node and a second load node, and the clamping circuit includes a second transistor device and a drive circuit. The second transistor device includes a control node and a load path connected in parallel with the load path of the first transistor device, and the drive circuit includes a capacitor coupled between the second load node of the first transistor device, and a first resistor coupled between the control node of the second transistor device and a further circuit node.

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.

An overcurrent protection circuit includes switches, resistors, and a voltage divider. A first switch includes a first control terminal and switches current to a load. The first resistor is connected in series with the first switch. The second resistor is connected in series with a second control terminal of the second switch and an output terminal of the overcurrent protection circuit. The voltage divider is connected in series with the second switch and has a center terminal connected to the first control terminal. A DC source voltage is across the second switch and the voltage divider. A latching circuit is provided by the switches, the voltage divider, the first resistor and the load. The second switch discharges the first switch to limit current to the output terminal in response to a voltage drop across the first resistor indicating current supplied to the output terminal has exceeded a threshold.

The present disclosure discloses a composite switching circuit, including a plurality of first semiconductor devices connected in series; and at least one second semiconductor device each connected in parallel to one of the plurality of first semiconductor devices. The composite switching circuit is connected to an input source. The second semiconductor device is turned off during a preset period to transfer a current flowing through the second semiconductor device to the first semiconductor devices connected in parallel to the second semiconductor device.

An intelligent power module and a controller for an air conditioner are provided. For the intelligent power module, an adjust circuit is additionally provided between a respective drive circuit and a respective IGBT transistor. The adjust circuit detects a change in the voltage of a low voltage power supply of the intelligent power module in real time, and disables the output of the module when the voltage is detected to be too low due to fluctuation of the low voltage power supply. This operation releases the charge accumulated in the IGBT transistor, when energy storage of a drive motor causes charge accumulation of the IGBT transistor. The adjust circuit can continue releasing the charge when the low voltage power supply is restored to normal, to prevent the operating reliability of the module from being affected by the impact of the charge on internal circuits of the module.

A programmable or configurable non-contact solid state switch device and method are provided for emulating a high reliability switch. The switch device senses position information related to a switch and is calibrated using a learning operation to learn position information of mechanical features of the switch and to map the positions of these features. Electrical outputs or functions are assigned to the mapped positions and stored such that the switch device generates the outputs when their corresponding positions are sensed. A switch device is uniquely configured to the mechanical system in which it operates.

A power conversion device including a semiconductor switching element having a control electrode terminal and two main electrode terminals and configured to control a current flowing between the two main electrodes by a drive signal applied to the control electrode terminal; and a drive circuit configured to generate the drive signal in synchronization with an input signal and to turn on/off the semiconductor switching element by the drive signal. The drive circuit is configured to detect the current flowing between the two main electrode terminals of the semiconductor switching element at a timing at which the semiconductor switching element is turned off, and to adjust a drive capacity.

An overcurrent protection circuit includes switches, resistors, and a voltage divider. A first switch includes a first control terminal and switches current to a load. The first resistor is connected in series with the first switch. The second resistor is connected in series with a second control terminal of the second switch and an output terminal of the overcurrent protection circuit. The voltage divider is connected in series with the second switch and has a center terminal connected to the first control terminal. A DC source voltage is across the second switch and the voltage divider. A latching circuit is provided by the switches, the voltage divider, the first resistor and the load. The second switch discharges the first switch to limit current to the output terminal in response to a voltage drop across the first resistor indicating current supplied to the output terminal has exceeded a threshold.

A switch having a drain, a source, and a control. The switch comprising a depletion-mode transistor including a first, a second, and a control terminal and an enhancement-mode transistor including a first, a second, and a control terminal. The first terminal of the depletion-mode transistor is the drain of the switch and the control of the depletion-mode transistor is coupled to the source of the switch. The control of the enhancement-mode transistor is coupled to the control of the switch, the second terminal of the enhancement-mode transistor is the source of the switch. The switch comprises a clamp circuit to clamp a voltage of the first terminal of the enhancement-mode transistor to a threshold, the clamp circuit comprises a resistor and a pn-junction device coupled between the first and second terminals of the enhancement-mode transistor and between the second terminal and the control of the depletion-mode transistor.

A system is provided. The system includes a semi-conductor device and a gate drive board. The gate drive board provides a voltage to the semi-conductor device. The system also includes a controller and a monitoring circuit. The controller drives the voltage provided by the gate drive board. The monitoring circuit is coupled to the gate drive board to monitor operations of the controller and the semi-conductor device.