A circuit breaker system is disclosed in the present application. The circuit breaker system includes a housing to hold an electrical interrupter within an internal region separated from an external ambient region. The electrical interrupter includes at least a first pair of electrical contact elements that are movable between open and closed positions. A voltage limiter, such as a metal oxide varistor (MOV), is connected across the pair of electrical contact elements to receive and dissipate a transient voltage when the first pair of electrical contacts is moved from a closed position to an open position, thereby reducing undesired arcing and premature wear or erosion of certain electrical components.

An electronic system for a surgical instrument is disclosed. The electronic system comprises a main power supply circuit configured to supply electrical power to a primary circuit. A supplementary power supply circuit configured to supply electrical power to a secondary circuit. A short circuit protection circuit coupled between the main power supply circuit and the supplementary power supply circuit. The supplementary power supply circuit is configured to isolate itself from the main power supply circuit when the supplementary power supply circuit detects a short circuit condition at the secondary circuit. The supplementary power supply circuit is configured to rejoin the main power supply circuit and supply power to the secondary circuit, when the short circuit condition is remedied.

An electronic system for a surgical instrument is disclosed. The electronic system comprises a main power supply circuit configured to supply electrical power to a primary circuit. A supplementary power supply circuit configured to supply electrical power to a secondary circuit. A short circuit protection circuit coupled between the main power supply circuit and the supplementary power supply circuit. The supplementary power supply circuit is configured to isolate itself from the main power supply circuit when the supplementary power supply circuit detects a short circuit condition at the secondary circuit. The supplementary power supply circuit is configured to rejoin the main power supply circuit and supply power to the secondary circuit, when the short circuit condition is remedied.

A system includes a current transformer including: a primary coil, and a secondary coil including at least two taps; a tap selection circuit; a current measurement apparatus configured to produce an indication of an amount of current flowing in the secondary coil; a power supply electrically connected to a first one of the taps, the power supply configured to receive electrical power from the first one of the taps; and a controller coupled to the power supply and the current measurement apparatus, the controller configured to receive electrical power from the power supply and to control the tap selection circuit based on the indication of an amount of current in the secondary coil.

Methods and systems for protecting one or more flexible alternating current transmission system (FACTS) devices in a high voltage (HV) power transmission line are disclosed. The system may include a circuit breaker to de-energize the HV power transmission line when a fault current is detected on the HV power transmission line, and to determine whether the fault current has cleared. The system may further include a power supply to harvest energy from the fault current. The system may further include a bypass switch coupled to protect the FACTS devices by providing a controllable conduction path around the FACTS devices when the bypass switch is activated. And the system may further include a fault current harvesting circuit (FHC) and an actuator operating in conjunction to control the bypass switch based on the harvested energy.

The present disclosure provides controllers for power distribution network circuit interrupting devices and provides electronic control circuits for inclusion in such controllers. The electronic control circuit has a boost circuit, a capacitor storage unit and a pulse width modulator control circuit. The boost circuit boosts an input voltage to a value to supply sufficient energy to a protective relay solenoid to energize the solenoid. The capacitor storage unit stores the boosted voltage from the boost circuit. The pulse width modulator control circuit is responsive to a control and enable circuit to selectively enable energy from the capacitor to energize the one or more protective relays in power distribution system circuit interrupting device.

The invention relates to a novel approach for the protection of electrical circuits from ground faults and parallel and series arc faults in a fully solid-state circuit configuration. Solid-state circuits and methods of use are described that provide the key functions of low-voltage DC power supply, mains voltage and current sensing, fault detection processing and high voltage electronic switching.

The invention relates to a novel approach for the protection of electrical circuits from ground faults and parallel and series arc faults in a fully solid-state circuit configuration. Solid-state circuits and methods of use are described that provide the key functions of low-voltage DC power supply, mains voltage and current sensing, fault detection processing and high voltage electronic switching.

A power supply system is operable to harvest power at low and high line currents. A current transformer is arranged to couple to a power transmission line. A current sensor which may be a Rogowski coil is arranged to couple to the power transmission line. Branches of power supply circuitry are connected to a plurality of secondary windings of the current transformer. A control circuit selects one of the branches of power supply circuitry, depending on sensed magnitude of line current, to provide electrical power to an output capacitor. Sufficient stored energy is also provided for performing a backup of operating parameters when the line current reduces to zero.

A virtual electronic circuit breaker having an electrical relay and a control circuit, the control circuit including a load and wire protection (“OC”) detection unit, a microprocessor and a driver. The OC detection unit is configured to monitor a power flow and the electrical relay is effective to control it. The driver is effective to cause the relay to stop the power flow upon receipt of a deactivation command. The OC detection unit is effective to cause the driver to receive a deactivation command if the OC detection unit senses that a short circuit condition or an overload condition exists. The microprocessor of the control unit is configured so as to be capable of, at least, receiving input from the OC detection unit and sending output to the driver.