A switch device includes first and second switch units that are coupled respectively to first and second output terminals. Each of the first and second switch units includes a plurality of diodes and at least one semiconductor-controlled rectifier (SCR), where at least one of the diodes and one of the at least one SCR cooperatively permit a current to flow therethrough to a corresponding one of the first and second output terminals when each thereof operates in an ON state, and where at least one of the diodes and one of the at least one SCR cooperatively permit a current to flow therethrough from a corresponding one of the first and second output terminals when each thereof operates in an ON state.

An AC switch (1) includes a first thyristor (T1), a second thyristor (T2), a third thyristor (T3), and a fourth thyristor (T4). The first thyristor (T1) has an anode connected to an AC power source (2), and a cathode connected to a load (3). The second thyristor (T2) is connected in antiparallel to the first thyristor (T1). The third thyristor (T3) has an anode connected to the AC power source (2), and a cathode connected to the load (3). The fourth thyristor (T4) is connected in antiparallel to the third thyristor (T3). A current detector (5) detects the AC current supplied from the AC power source (2) to the load (3). A controller (6) causes the first thyristor (T1) and the third thyristor (T3) to conduct alternately and causes the second thyristor (T2) and the fourth thyristor (T4) to conduct alternately, for each one-cycle period of the AC current, in accordance with the detection value from the current detector (5).

Systems, methods, techniques and apparatuses of power switch control are disclosed. One exemplary embodiment is a power switch comprising a thyristor-based branch including a thyristor device; a FET-based branch coupled in parallel with the thyristor-based branch and including a FET device; and a controller. The controller is structured to turn on the FET device, turn on the thyristor device after turning on the FET device based on a thyristor voltage threshold, and update the thyristor voltage threshold based on a voltage measurement corresponding to the thyristor-based branch measured while the thyristor device is turned on.

An AC switch (1) includes a first thyristor (T1), a second thyristor (T2), a third thyristor (T3), and a fourth thyristor (T4). The first thyristor (T1) has an anode connected to an AC power source (2), and a cathode connected to a load (3). The second thyristor (T2) is connected in antiparallel to the first thyristor (T1). The third thyristor (T3) has an anode connected to the AC power source (2), and a cathode connected to the load (3). The fourth thyristor (T4) is connected in antiparallel to the third thyristor (T3). A current detector (5) detects the AC current supplied from the AC power source (2) to the load (3). A controller (6) causes the first thyristor (T1) and the third thyristor (T3) to conduct alternately and causes the second thyristor (T2) and the fourth thyristor (T4) to conduct alternately, for each one-cycle period of the AC current, in accordance with the detection value from the current detector (5).

A solid state switch for connecting and disconnecting an electrical device has at least one FET-type device and at least one thyristor-type device coupled in parallel to the at least one FET-type device. A gate driver is operative to send gate drive signals to the at least one FET-type device and to the at least one thyristor-type device for providing current to the electrical device. The gate driver is constructed to control a split of the current as between the at least one FET-type device and the at least one thyristor-type device.

A solid state switch has at least one FET-type device and at least one thyristor-type device coupled in parallel to the at least one FET-type device. The at least one FET-type device is constructed with a first power loss profile based on a rated current of an electrical device; and the at least one thyristor-type device is constructed with a second power loss profile based on a surge current associated with the electrical device.

A switch device includes first and second switch units that are coupled respectively to first and second output terminals. Each of the first and second switch units includes a plurality of diodes and at least one semiconductor-controlled rectifier (SCR), where at least one of the diodes and one of the at least one SCR cooperatively permit a current to flow therethrough to a corresponding one of the first and second output terminals when each thereof operates in an ON state, and where at least one of the diodes and one of the at least one SCR cooperatively permit a current to flow therethrough from a corresponding one of the first and second output terminals when each thereof operates in an ON state.

A solid state switch for connecting and disconnecting an electrical device has at least one FET-type device and at least one thyristor-type device coupled in parallel to the at least one FET-type device. A gate driver is operative to send gate drive signals to the at least one FET-type device and to the at least one thyristor-type device for providing current to the electrical device. The gate driver is constructed to control a split of the current as between the at least one FET-type device and the at least one thyristor-type device.

A solid state switch has at least one FET-type device and at least one thyristor-type device coupled in parallel to the at least one FET-type device. The at least one FET-type device is constructed with a first power loss profile based on a rated current of an electrical device; and the at least one thyristor-type device is constructed with a second power loss profile based on a surge current associated with the electrical device.

A semiconductor switching device for switching high voltage and high current. The semiconductor switching device includes a control-triggered stage and one or more auto-triggered stages. The control-triggered stage includes a plurality of semiconductor switches, a breakover switch, a control switch, a turn-off circuit, and a capacitor. The control-triggered stage is connected in series to the one or more auto-triggered stages. Each auto-triggered stage includes a plurality of semiconductor switches connected in parallel, a breakover switch, and a capacitor. The control switch provides for selective turn-on of the control-triggered stage. When the control-triggered stage turns on, the capacitor of the control-triggered stage discharges into the gates of the plurality of semiconductor switches of the next highest stage to turn it on. Each auto-triggered stage turns on in a cascade fashion as the capacitor of the adjacent lower stage discharges or as the breakover switches of the auto-triggered stages turn on.