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.

The present disclosure uses a capacitive voltage divider to supply a voltage that can be more readily handled by mainstream semiconductor and magnetic components (generally less than 1000 volts). The divided system voltage, expected to be between 500 and 1000 volts, is then converted to a power supply voltage to be used by the measuring equipment. For safety reasons, this voltage is frequently required to be less than approximately 50 volts if it is delivered via a connectorized cable with exposed contacts.

High voltage clamps with active activation and activation-release control are provided herein. In certain configurations, a clamp can have scalable operating clamping voltage level and can be used to protect the electrical circuit connected to a power supply of a semiconductor chip from damage from an overstress event, such as electrostatic discharge (ESD) events. The pins of the power supply are actively monitored to detect when an overstress event is present, and the clamp is turned-on in response to detecting the overstress event. A timer is used to shut down the clamp after a time delay from detecting the overstress event, thereby providing a false detection shutdown mechanism that prevents the protection clamp from getting falsely activated and remain in the on-state during normal circuit operation.

Flexible AC transmission system (FACTS) enabling distributed controls is a requirement for power transmission and distribution, to improve line balancing and distribution efficiency. These FACTS devices are electronic circuits that vary in the type of services they provide. All FACTS devices have internal circuitry to handle fault currents. Most of these circuits are unique in design for each manufacturer, which make these FACTS devices non-modular, non-interchangeable, expensive and heavy. One of the most versatile FACTS device is the static synchronous series compensator (SSSC), which is used to inject impedance into the transmission lines to change the power flow characteristics. The addition of integrated fault current handling circuitry makes the SSSC and similar FACTS devices unwieldy, heavy, and not a viable solution for distributed control. What is disclosed are modifications to FACTS devices that move the fault current protection external to the FACTS device and make them modular and re-usable.

A current transient suppression circuit includes an inductor electrically connected to a test signal by an input of the inductor, at least one switching device electrically connected to an output of the inductor, and an output of the at least one switching device connected to a shunt path. A method of suppressing current transients in a circuit includes receiving a test signal at an inductor, and when the test signal comprises a current transient, the current transient is received at the inductor, activating at least one switching device electrically connected to the inductor to shunt the current transient away from a device under test.

In some examples, a control circuit for a bypass capacitor includes a switch assembly that is activatable between a first state to connect the bypass capacitor between nodes, and a second state to disconnect the bypass capacitor between the nodes. The switch assembly includes a first switch to activate a first path comprising a first resistance to begin charging the bypass capacitor, and a second switch to, a delayed time after the activating of the first path, activate a second path comprising a second resistance lower than the first resistance, the activated second path connecting the bypass capacitor between the nodes.

The invention relates to a surge protected power supply for feeding a device with electrical energy. The power supply includes a surge protection device SPD connected in series with a controllable switch where this series connection is connected between two current conductors of the power supply. The power supply further includes a device for determining a comparison voltage such that the comparison voltage is in some form indicative of a surge voltage present at the input of the power supply. This comparison voltage then is compared to a threshold. If the comparison voltage is higher than the threshold, the controllable switch is closed such that the SPD in series with the switch is effectively connected between the two current conductors to divert the surge current through the SPD. If the comparison voltage is lower than the threshold the switch remains open.

A method for operating an electrical circuit for controllably delivering power from a power source to an electrical load including a switch further configured to operate in a first conducting mode and a second non-conducting mode, and a controller, the method includes ceasing delivering power from the power source to the electrical load.

A transient voltage suppressor (TVS) is constructed as an NPN bipolar transistor including individually optimized collector-base and emitter-base junctions both with avalanche mode breakdown. The TVS device is constructed using a base that includes a lightly doped base region bordered by a pair of more heavily doped base regions. The two more heavily doped base regions are used to form the collector-base junction and the emitter-base junction both as avalanche breakdown junctions. The lightly doped base region between the collector-base and emitter-base doping regions ensures low leakage current in the TVS device. In this manner, the TVS bipolar transistor of the present invention provides high surge protection with robust clamping while ensuring low leakage current.

An electrical filter is disclosed. The electrical filter can include a conductive concrete structure including at least one of a conductive carbon material, a magnetic material, or a conductive metallic material. The conductive concrete structure is characterized by an electrical conductivity greater than 0.5 siemens per meter. The electrical filter also includes at least one electrical cable disposed within the conductive concrete structure. The at least one electrical cable includes an input to receive an electrical signal and an output to output an attenuated electrical signal.