A circuit and method are disclosed enabling a direct current (DC) power source to power a load circuit designed for alternating current (AC) input. The circuit is arranged to be connected between a DC power source and a load circuit in which the load circuit includes an electric load and a switch with a mechanical contact in series with the load. The circuit comprises a contact opening detector arranged to detect an opening event of the switch contact and a damping component arranged to be triggered in response to the contact opening detector detecting a contact opening event. The triggered damping component causes a momentary lowering of a load circuit input voltage, such that the momentary lowering of the load circuit input voltage prevents the sustaining of an electric arc across the opened switch contact.

Intelligent electrical switches are provided to implement multi-way circuits using two or more intelligent electrical switches for controlling power to a load.

Intelligent electrical switches are provided to implement multi-way circuits using two or more intelligent electrical switches for controlling power to a load.

There may be two active snubbers for direct current (dc) solid-state circuit breakers (SSCBs): metal-oxide-varistor with resistor-capacitor-switch (MOV-RCS) and active-MOV with resistor-capacitor-diode (AMOV-RCD). In the snubber branch, either half- or full-controlled switch can be used, leading to four topologies. The improved snubbers offer several improvements: 1) MOV is disconnected from the power line during SSCB OFF-state, which enhances reliability as neither voltage nor power appears on MOV; 2) voltage utilization rate ηv of the main switch is remarkably increased, which improves efficiency and power density, and reduces design cost shows experiments of five prototypes are conducted including four proposed snubbers and a comparison with conventional MOV-RCD snubber.

There may be two active snubbers for direct current (dc) solid-state circuit breakers (SSCBs): metal-oxide-varistor with resistor-capacitor-switch (MOV-RCS) and active-MOV with resistor-capacitor-diode (AMOV-RCD). In the snubber branch, either half- or full-controlled switch can be used, leading to four topologies. The improved snubbers offer several improvements: 1) MOV is disconnected from the power line during SSCB OFF-state, which enhances reliability as neither voltage nor power appears on MOV; 2) voltage utilization rate ηv of the main switch is remarkably increased, which improves efficiency and power density, and reduces design cost shows experiments of five prototypes are conducted including four proposed snubbers and a comparison with conventional MOV-RCD snubber.

An electric device comprises a first and second voltage sensor, a current sensor, an actuator and a controller. The first voltage sensor senses a first voltage at a first contact of a switch inside the electric device and generates a first voltage signal indicating the first voltage, the first contact of the switch coupled to a source line. The second voltage sensor senses a second voltage at a second contact of the switch and generates a second voltage signal indicating the second voltage, the second contact is coupled to a reactive component. The current sensor senses a current at the second contact of the switch and generates an output signal indicating the current. The controller is coupled to the voltage sensors, the current sensor and the actuator and causes, based on at least one of the voltage and current signals, the actuator to actuate one of the contacts to execute switching at a predetermined point of the first voltage.

Systems and methods for contact erosion mitigation are provided. To perform contact erosion mitigation, an order of opening/closing poles and/or contact relays of particular poles is altered, resulting in a sharing of potential arcing conditions amongst the poles/contact relays of these poles.

Systems and methods for contact erosion mitigation are provided. To perform contact erosion mitigation, an order of opening/closing poles and/or contact relays of particular poles is altered, resulting in a sharing of potential arcing conditions amongst the poles/contact relays of these poles.

A modular accessory device and a transmitter device for coupling to the modular accessory device are provided. The modular accessory device comprises a first connector module for coupling to a first transmitter device, the first connector module comprising a first input member; a power source controller coupled to the first connector module, the power source controller further arranged to be coupled to a power source; a visual indicator member coupled to the first connector module; wherein the first input member is arranged to receive a signal from the first transmitter device to instruct a first provision of power from the power source to the first transmitter device and a second provision of power to the visual indicator member; and further wherein the visual indicator member is arranged to be activated based on an indicator control signal received from the first transmitter device via the first input member.

A modular accessory device and a transmitter device for coupling to the modular accessory device are provided. The modular accessory device comprises a first connector module for coupling to a first transmitter device, the first connector module comprising a first input member; a power source controller coupled to the first connector module, the power source controller further arranged to be coupled to a power source; a visual indicator member coupled to the first connector module; wherein the first input member is arranged to receive a signal from the first transmitter device to instruct a first provision of power from the power source to the first transmitter device and a second provision of power to the visual indicator member; and further wherein the visual indicator member is arranged to be activated based on an indicator control signal received from the first transmitter device via the first input member.