An electrical system includes an input node electrically connectable to a power supply. The system includes a plurality of voltage suppressors, with at least one of the voltage suppressors electrically connected to the input node. A voltage selection switch is electrically connected to at least one of the plurality of voltage suppressors. A controller in communication with the switch may selectively operate the switch based on a nominal operating voltage at the input node.

A spike suppression circuit includes a wide bandgap transistor, a first transistor, a clamping circuit, and a capacitor. The wide bandgap transistor is depletion-type. The first transistor is coupled in series with the wide bandgap transistor. The clamping circuit provides a voltage difference, and is coupled to a common node between the wide bandgap transistor and the first transistor. The capacitor provides a supply voltage for the clamping circuit. When the first transistor is turned off, the capacitor can recycle spike energy at the common node.

The disclosed technology generally relates to electrical overstress protection devices, and more particularly to electrical overstress monitoring devices for detecting electrical overstress events in semiconductor devices. In one aspect, an electrical overstress monitor and/or protection device includes a two different conductive structures configured to electrically arc in response to an EOS event and a sensing circuit configured to detect a change in a physical property of the two conductive structures caused by the EOS event. The two conductive structures have facing surfaces that have different shapes.

The present application relates to a near field communication (NFC) device which has an antenna for receiving NFC signals. The NFC device includes a protection system for protecting a transmit/receive system, and other systems, of the NFC device from potentially damaging voltages that may develop at an output of the antenna if the device enters a strong magnetic field. The protection system includes current control devices that are operative to source or sink current depending upon the polarity of a signal at an output of the antenna, to generate a voltage which at least partially negates a positive or negative voltage at the output of the antenna, thereby reducing the peak voltage at the antenna output.

An example method for monitoring the operation of a metal-oxide varistor (MOV) may involve monitoring an operating value of at least one parameter of the MOV using at least one sensor. Further, the method may involve determining, using one or more processors, that a difference between the operating value and a reference value corresponding to the at least one parameter satisfies a predetermined threshold condition corresponding to the at least one parameter. And the method may involve responsive to determining that the difference between the operating value and the reference value satisfies the predetermined threshold condition, transmitting a notification indicative of a potential failure of the MOV to at least one device.

A varistor failure detector includes one or more surge detector in communication with a varistor, to detect surges shunted by the varistor and a processor, in communication with the at surge detector(s). The processor is programmed to count surges shunted by the varistor, as indicated by the surge detector (s) and store at least one count representing a cumulative count of surges shunted by the varistor. An indicator of the count may be provided to an operator to indicate that the varistor should be replaced, to avoid catastrophic failure of the varistor.

Aspects of the present disclosure provide miniaturized isolator modules capable of transferring power and/or data signals across an isolation barrier by way of a transformer while maintaining intrinsic safety (IS) compliance. For example, the isolator modules may provide power from a non-IS side to an IS side of the isolation barrier while protecting the IS side in the event of an overvoltage and/or overcurrent event on the non-IS side. In some aspects, an isolator module includes one or more silicon protection devices, which facilitate the miniaturization of the isolator module while maintaining protection against overvoltage and/or overcurrent events in accordance with IS standards. In some aspects, an isolator module includes a transformer adapted for IS compliance. For example, coils of the transformer may be disposed on opposing sides of an isolation barrier having a thickness of at least 200 microns. Some aspects provide silicon protection devices formed on a single semiconductor die for use with miniaturized isolator modules to provide overvoltage and/or overcurrent protection for IS compliance. Miniaturized isolator modules and protection devices described herein may be used either alone or in combination, in IS or non-IS environments.

The object of the invention is an overvoltage protection apparatus with monitoring function having a parallel circuit of two branch circuits, wherein the first branch circuit has a first overvoltage protection device and a second overvoltage protection device that are connected in series, wherein the second branch circuit has a third device and a fourth device that are connected in series, wherein the first overvoltage device and the third device have a first shared voltage potential during operation, and wherein the second overvoltage device and the fourth device have a second shared voltage potential during operation, wherein a first measuring tap is provided between the first overvoltage protection device and the second overvoltage protection device and wherein a second measuring tap is provided between the third device and the fourth device, with a signal being derived from the voltage between the first measuring tap and the second measuring tap that provides state information in relation to the first overvoltage protection device and the second overvoltage protection device.

An overvoltage protection circuit which can be applied to a motor controller is provided. The overvoltage protection circuit is coupled to an input terminal for receiving an input voltage. The overvoltage protection circuit comprises a switch circuit, a controller, and a comparing unit. When the input voltage is greater than a first voltage, a discharging mechanism is forced to start so as to suppress a voltage spike. When the input voltage is less than a second voltage, the discharging mechanism is closed so as to operate normally.

A motor wiring member configured to supply three-phase alternating current to a motor includes conductive wires, each of which has a connecting portion being provided at one end and being configured to be connected to a coil end of a stator of the motor, a terminal being provided at an other end of each conductive wire and being configured to be connected to an electrode of a terminal block, and a surge suppression section being configured to suppress an overvoltage from being applied to the motor. The surge suppression section includes three series circuits, each of which includes a resistor and a capacitor. One ends of the three series circuits are electrically connected to the conductive wires of respective phases, and other ends of the three series circuits are electrically connected to each other. The surge suppression section is provided along with the conductor wires near the terminal and is located between the terminal and the connecting portion.