A switching device (28) comprising a primary switching block (30) including at least one semiconductor switch (34); and a switching control unit (32) to control the switching of the or each semiconductor switch (34). The switching device further includes a crowbar circuit (46) comprising a crowbar switch (56) switchable to selectively allow current to flow through the crowbar switch (56) in order to bypass the or each switching module; and a secondary switching block including a switching element (58) connected across a control electrode and a cathode of the crowbar switch (56). The switching element (58) is in communication with the switching control unit (32) to receive, in use, a control signal (66) generated by the switching control unit (32) when the primary switching block (30) is operating within predefined operating parameters.

A silicon-controlled rectifier (SCR) includes a first-type field, a second-type first field and a second-type second field disconnectedly formed in a first-type well; an entire first-type doped region formed within the first-type field; a segmented second-type doped region formed within the second-type first field; and a segmented first-type doped region formed within the second-type second field.

Apparatus and methods for nanoplasma switches are disclosed. In certain embodiments, a nanoplasma switching system includes a nanoplasma radio frequency (RF) switch that receives an RF signal, and a nanoplasma DC switch that receives a DC bias voltage. The nanoplasma DC switch is positioned adjacent to but spaced apart from the nanoplasma RF switch. The nanoplasma DC switch induces a nanoplasma through the nanoplasma RF switch when the DC bias voltage is set to a first voltage level. By implementing the nanoplasma switching system in this manner, DC bias to turn on or off the nanoplasma RF switch can be realized without needing to use passive components such as DC blocking capacitors, choke inductors, or baluns for isolation.

A circuit and a method for improving efficiency by use of external inductor for temperature control, wherein the operating temperature of a field effect transistor is calculated by the inductor voltage. The change in operating temperature is used to adjust and control the voltage of the variable voltage gate drive module. When the operating temperature rises, the input voltage of the gate increases accordingly; when the operating temperature decreases, the input voltage of the gate decreases accordingly, thereby achieving the efficiency of regulating light and heavy loads.

An output MOS transistor has a drain connected with a power supply and a source connected with an output terminal. The short-circuit MOS transistor has a source connected with the output terminal. The short-circuit MOS transistor is formed in a semiconductor substrate connected with the power supply. A switching device is formed in a semiconductor region which is formed in the semiconductor substrate, and contains a first diffusion layer connected with the gate of the output MOS transistor and a second diffusion layer formed in the semiconductor region and connected with the drain of the short-circuit MOS transistor.

A semiconductor relay device includes a conversion circuit configured to receive an input signal from outside and pass a first current to a first node based on the input signal. A zener diode has an anode coupled to a second node and a cathode coupled to the first node. A resistor is coupled between the second node and a third node. A number n of diodes are serially coupled. A thyristor has an anode coupled to the first node, a cathode coupled to the second node, and a control terminal coupled to the third node. A transistor has a gate coupled to the first node. An anode of a diode at a first end of the n diodes is coupled to the first node, and a cathode of a diode at a second end of the n diodes is coupled to a third node.

A semiconductor relay device includes a conversion circuit configured to receive an input signal from outside and pass a first current to a first node based on the input signal. A zener diode has an anode coupled to a second node and a cathode coupled to the first node. A resistor is coupled between the second node and a third node. A number n of diodes are serially coupled. A thyristor has an anode coupled to the first node, a cathode coupled to the second node, and a control terminal coupled to the third node. A transistor has a gate coupled to the first node. An anode of a diode at a first end of the n diodes is coupled to the first node, and a cathode of a diode at a second end of the n diodes is coupled to a third node.

A thyristor-based dc solid state circuit breaker (SSCB) named Y-type includes a new complementary commutation circuit including a capacitor-capacitor pair, which features three advantages. First, a fast commutation is achieved using a countercurrent pulse injection by the capacitor-capacitor pair structure. Second, metal-oxide varistors (MOVs) are disconnected from the power line when SSCB is OFF, which solves the reliability issue due to the MOV degradation and enhances the voltage utilization rate of the main switch. Third, benefiting from the capacitor-capacitor pair structure, reliable reclosing and rebreaking are obtained for practical applications.

A thyristor-based dc solid state circuit breaker (SSCB) named Y-type includes a new complementary commutation circuit including a capacitor-capacitor pair, which features three advantages. First, a fast commutation is achieved using a countercurrent pulse injection by the capacitor-capacitor pair structure. Second, metal-oxide varistors (MOVs) are disconnected from the power line when SSCB is OFF, which solves the reliability issue due to the MOV degradation and enhances the voltage utilization rate of the main switch. Third, benefiting from the capacitor-capacitor pair structure, reliable reclosing and rebreaking are obtained for practical applications.