A power conversion circuit has a controller with an input terminal and a circuit configured to drive an electric current out of the input terminal in response to a condition of the controller. An indicator is coupled to the input terminal of the controller. The controller includes a clock signal controlling the electric current out of the input terminal. The input terminal is a voltage sensing terminal or feedback input terminal in some embodiments.

An alternating current (AC) inverter includes a converter circuit configured to convert a direct current (DC) voltage to an AC voltage, and output terminals, the converter circuit being configured to output the AC voltage to the output terminals. The AC inverter further includes a signal terminal configured to receive a signal from outside of the AC inverter, and a control circuit configured to detect an abnormality related to the AC inverter, control the converter circuit to stop conversion of the DC voltage to the AC voltage in response to detection of the abnormality, and control the converter circuit to resume conversion of DC voltage to the AC voltage in response to reception of the signal on the signal terminal.

An electric safety circuit for an aircraft DC power supply circuit includes a first electric line connecting a first electric pole of a main DC power supply with a first electric connector of an electric load; a second electric line connecting a second electric pole of the main DC power supply with a second electric connector of the electric load; at least one electric safety switch arranged in at least one of the first and second electric lines and configured for selectively interrupting any electric current flowing through said at least one electric line; a first electric coil arranged in the first electric line.

A photovoltaic inverter includes: an input unit to connected to a first terminal and a second terminal to which a positive (+) polarity or a negative (−) polarity of a photovoltaic module are connected; a switching device configured to control the first terminal and the second terminal connected to the input unit according to pre-set polarities of an inverter unit; a booster unit configured to boost a voltage of the photovoltaic module delivered form the input unit through the switching device; a capacitor configured to charge the voltage boosted by the booster unit; and an inverter unit configured to convert the voltage charged in the capacitor into an alternating current (AC) and provide the converted AC voltage for an electric power system.

An apparatus and method for greatly increasing power line surge/transient resistance of power semiconductors in inductive heating equipment, in which a sample of the instantaneous line voltage or its rectified equivalent is applied to a comparator input terminal, and a reference voltage corresponding to a predetermined surge shutdown voltage is applied to an opposite comparator input, such that comparator output changes state in response to the predetermined surge shutdown voltage, and is functionally connected to gate drive circuitry to disable gate drive circuitry for the duration of the surge/transient.

In a three-level chopper apparatus, a protection switch circuit is controllable to change a current pathway through which an overvoltage is applied to a second capacitor or a first capacitor to a current pathway through which no overvoltage is applied to the second capacitor or the first capacitor.

Systems and methods for gate driver with field-adjustable undervoltage lockout (UVLO) are disclosed. A gate driver system comprises a control circuit and a driver circuit. The driver circuit incorporates a field-adjustable UVLO, a control logic, and an inverter. The level of the field-adjustable UVLO is adjustable by an external circuit, which can be a resistor based voltage divider. By setting the UVLO level externally adjustable and by moving a reference ground to the external voltage divider, the gate driver system is able to implement gate control for various load without needing extra ground pin.

An inverter includes a positive electrode terminal and a negative electrode terminal, upper-arm switching elements and lower-arm switching elements, and a voltage divider that supplies partial voltages of a voltage between the positive electrode terminal and the negative electrode terminal to a gate and a drain, respectively, of the lower-arm switching element. The lower-arm switching element includes an HEMT. In the voltage divider, the partial voltages are set to turn the lower-arm switching element off when a positive electrode and a negative electrode of a DC power supply are reversely connected to the positive electrode terminal and the negative electrode terminal, respectively.

Protection of an electric motor drive controller from a transient voltage is described herein. The transient voltage is provided by an alternating current (AC) power line that includes a line conductor, a neutral conductor, and a ground conductor. The transient voltage protection system includes a first stage protection device coupled to an input of a rectifier of the motor drive controller. The first stage protection device is configured to suppress the transient voltage to prevent damage to the motor drive controller. The transient voltage protection system also includes a second stage protection device coupled between the rectifier and an inverter of the motor drive controller. The second stage protection device is configured to further suppress the transient voltage to prevent damage to the inverter.

A power supply for supplying power to a chipset includes a first voltage regulating circuit, which is configured to convert an applied power supply signal into a group of first supply voltages, and a second voltage regulating circuit, which is configured to convert the applied power supply signal into a group of second supply voltages. A control circuit is provided, which is configured to selectively enable the second voltage regulating circuit to generate the group of second supply voltages. An output discharge circuit is provided, which is configured to discharge an output stage of the first voltage regulating circuit in response to a transition of the first voltage regulating circuit from an active state to an inactive state. This transition of the first voltage regulating circuit from an active state to an inactive state can occur in response to a change in magnitude of the power supply signal.