The present disclosure provides a DC mechanical circuit breaker that can utilize two switches, one of which can generate zero-crossing with an alternate oscillatory circuit for the other one, which can be a conventional zero-crossing-based AC breaker and can be used in the main circuit. This is different from the conventional single-switch commute-and-absorb method currently used. The present disclosure shows that disclosed circuit breaker improves the fault current extinction and significantly reduces the voltage rate-of-change while creating the current zero-crossing faster compared to the available technology. Thus, disclosed circuit breaker is capable of interrupting high DC currents with minimal arc through a less expensive AC circuit breaker. Simulation and hardware results are provided to show the efficiency of the disclosed circuit breaker.

A heterojunction device having at least three terminals, the at least three terminals comprising a high voltage terminal, a low voltage terminal and a control terminal. The heterojunction device further comprises at least one main power heterojunction transistor, an auxiliary gate circuit comprising at least one first low-voltage heterojunction transistor, a pull-down circuit comprising a capacitor and a charging path for the capacitor. The heterojunction device further comprises at least one monolithically integrated component, wherein the capacitor is configured to provide an internal rail voltage for the at least one monolithically integrated component.

The Robust Safe Switch and Control Device is an “Internet of Things” end effecter that provides a minimally dissipating, robust switch tightly integrated with circuit, life and property automated safety features. The device enables extended sensing and monitoring capabilities that enable the effective management of the “Internet of Things.”

A thyristor switch is constituted of a pair of arms connected in anti-parallel, each of the anus including a plurality of thyristors connected in series. A controller includes a phase detecting unit configured to detect a phase of a power supply voltage supplied from an alternating-current power supply, and a gate signal generating unit configured to interrupt a gate signal when an open command is provided to the static switch and the phase of the power supply voltage detected by the phase detecting unit matches a target phase. The target phase is set outside of a phase range where interruption of the gate signal is prohibited, the phase range being set so as to include a zero crossing point at which a load current is switched in polarity.

In one aspect, a solid-state switching apparatus is provided that includes a pair of anti-parallel thyristors, a quasi-resonant turn-off circuit, a sensor, and a control circuit. The turn-off circuit is coupled in parallel with the pair of anti-parallel thyristors and includes a first selectively conductive path and a second selectively conductive path. The sensor is configured to sense a thyristor current conducted by at least one of the pair of anti-parallel thyristors. The control circuit is configured to receive the sensed thyristor current from the sensor and determine a magnitude of the sensed thyristor current and a polarity of the sensed thyristor current. The control circuit is further configured to activate, in response to determining that the magnitude is greater than a threshold value, one of the first selectively conductive path and the second selectively conductive path based on the polarity to commutate and interrupt the thyristor current.

A power supply unit for use with thermostats or other like devices requiring power. A power supply unit may be designed to keep electromagnetic interference emissions at a minimum, particularly at a level that does not violate governmental regulations. A unit may be designed so that there is enough power for a triggering a switch at about a cross over point of a waveform of input power to the unit. Power for triggering may come from a storage source rather than line power to reduce emissions on the power line. Power for the storage source may be provided with power stealing. Power stealing may require switching transistors which can generate emissions. Gate signals to the transistors may be especially shaped to keep emissions from transistor switching at a minimum.

A static transfer switch is provided for supplying power to a load alternately from two different power sources. Switching between the two power sources may occur within a fraction of one electrical cycle. In response to sensing degraded performance in the power source supplying the load, a main circuit is turned off with a resonant turn off circuit. The resonant turn off circuit is shared between the main circuits of two different power sources such that the resonant turn off circuit is connected to the main circuit of whichever power source is currently supply power to the load.

Driver circuit in which a capacitor (4), in a manner controlled by a switch control device (9) which is connected downstream of a current measuring device (8), is charged to a reference voltage (Ur) by means of a charging current (Ic2), and the charged capacitor is discharged in an oscillating manner via an inductor coil (1), wherein the discharging operation is terminated when the current (Ia) through the inductor coil has passed through an entire oscillation period or several oscillation periods, wherein a first controllable switch (5) is connected in series between a first non-reactive resistor (6) and the first capacitor (4) in one of two input paths. Furthermore, a second controllable switch (7) and a fourth controllable switch (14) are connected into two output paths, and a second non-reactive resistor (13) is connected between a second connection (X2) of the inductor coil (1) and a connection for Na reference potential (Um). The current measuring device (8) is connected between the fourth controllable switch (14) and the first capacitor (4).

A switching device is provided for disconnecting or connecting an electric machine, a converter or a plurality of electrical loads supplied with AC power from a power supply and controlled by a control unit. The switching device includes a current sink and at least one mechanical switch in the switching device are arranged in a circuit. The current sink is arranged, upon receipt of a signal, to close and sink the current, and the at least one mechanical switch is arranged to open and break the current on receipt of a signal to open supplied to the electric machine when the current load is at or close to zero. A method and a computer program for carrying out the method are described.

A static transfer switch is provided for supplying power to a load alternately from two different power sources. Switching between the two power sources may occur within a fraction of one electrical cycle. In response to sensing degraded performance in the power source supplying the load, resonant turn off circuits connected directly to the main switches of two phases of the power source are actuated to commutate the respective main switches. The main switch of the third phase is commutated with one or more of the resonant turn off circuits through the delta side of a transformer connected to the three phases of the power source.