Abstract: A protection circuit of a semiconductor device includes a high electron mobility transistor and a protection element. Between the drain and the gate of the high electron mobility transistor, the protection element includes: a thyristor; and a first resistor connected in series to the thyristor. Between the source and the gate of the high electron mobility transistor, the protection element includes: a second resistor and an interrupter that is connected in series to the second resistor. The interrupter interrupts a flow of a current between the drain and the gate when the thyristor is turned off, and the interrupter permits the current to flow between the drain and the gate when the thyristor is turned on.

Abstract: A gate driver is provided for controlling a gate voltage of each of a plurality of MOS control semiconductor devices, such as IGBTs or metal oxide MOS transistors, of a semiconductor power converter in which said MOS control semiconductors are connected in series with each other, the gate driver includes a power supply line having a higher potential than a gate potential on each of said MOS control semiconductor devices when in steady ON state, and an arrangement for supplying a current from the power source line to the gate of each of said MOS control semiconductors to increase the gate voltage of the MOS control semiconductor devices when a potential difference between said power supply line and an emitter of each of said MOS control semiconductors is constant and when a collector voltage of the MOS control semiconductor device exceeds a predetermined value under ON state of the MOS control semiconductor device.

Abstract: An AC transfer switch (ATS) is provided for switching a system load between at least two AC lines. A first bridge rectifier is connected to a first AC line for providing a first full wave rectified AC waveform. A first pair of oppositely poled silicon controlled rectifiers (SCRs) is coupled to the first bridge rectifier and to the system load. A second bridge rectifier is connected to a second AC line for providing a second full wave rectified AC waveform. A second pair of oppositely poled silicon controlled rectifiers (SCRs) coupled to the second bridge rectifier and to the system load. Control logic is coupled to a gate input of the first pair of oppositely poled silicon controlled rectifiers (SCRs) and a gate input of the second pair of oppositely poled silicon controlled rectifiers (SCRs) for applying one of the first full wave rectified AC waveform or the second full wave rectified AC waveform to the system load.

Abstract: A control arrangement and method is provided for a power electronic system configured as a high-speed source-transfer switching systems (HSSTSS). The HSSTSS supplies an electrical load with alternating current from either a first source or a second source via respective first and second solid-state switches. The HSSTSS also includes a controller that samples the voltage waveforms of each of the first and second sources to detect when transfer between the sources is desirable, e.g. outages or voltage that is either too low or too high. The controller provides appropriate control signals to control operation of the solid-state switches and transfer supply of the load therebetween. The control arrangement avoids undesirable current flow between sources via a comparison of the voltages of the sources and current in the outgoing source, i.e.

Abstract: A high voltage switch in which an extended SCR is built in an insulated polysilicon layer for providing a single structure high voltage switch. The high voltage SCR is built by building unit SCRs comprising a cathode, a gate, an anode and a voltage sustaining area. The unit SCRs are built as horizontal linear devices. The unit SCRs can then be combined to form a large SCR by building each unit SCR so that the anode of one SCR is at least partially contiguous with the cathode of the next unit SCR.

Abstract: A gate power supply circuit including a switching device and a gate drive circuit connected to the switching device for generating a gate signal to be supplied to a gate of the switching device. The gate power supply circuit further includes a series circuit of a snubber capacitor and a snubber diode connected in parallel with the switching device, and an inductor, a first terminal of which is connected to a connection point of the switching device and the snubber diode. The gate power supply circuit also includes a series circuit of power disposing circuit and a first diode, connected between a series connection point of the snubber capacitor and the snubber diode and a second terminal of the inductor. The gate power supply circuit further includes a series circuit of a power supplying capacitor and a second diode, connected in parallel with the inductor.

Abstract: A new SCR (silicon controlled rectifier) controller characterized by comprising input circuits, SCR trigger circuits, charge circuits, commutation capacitor, discharge circuits and SCR and being constructed in such way that when the input pulse is positive, it will work to activate the trigger and cause the SCR to be in turn-on state as well as to charge the commutation capacitor and when the input pulse is zero, the stored energy of the commutation capacitor will discharge to cause the SCR to be in turn-off state so that it does not need any other electric energy to attain the objective to cut off the source.