An apparatus includes multiple circuit paths configured to generate multiple electrical signals to be used to communicate with multiple devices. Each of the circuit paths is configured to use electrical energy from a different one of multiple independent power supplies. The apparatus also includes an I/O terminal configured to be coupled to a common electrical conductor that is coupled to the multiple devices. The I/O terminal is configured to pass the electrical signals to the common electrical conductor. The apparatus is configured to use each of the electrical signals to one of: receive input data from one of the multiple devices or provide output data to one of the multiple devices.

A circuit breaker includes at least one moveable contact. The moveable electrode is operably connected to a Thomson coil actuator that can separate and open the contacts of the circuit breaker. A sensor senses current or voltage in the circuit breaker. When a condition exists that triggers an opening action, a controller will use select a current level to apply to the Thomson coil actuator. The selected current level will vary based on the sensed current or voltage level. The controller will cause a driver to apply the selected current level to the Thomson coil actuator, and it will cause the contacts to separate and open. If the circuit breaker is a vacuum interrupter, the vacuum interrupter may employ a multi-section bellows in which each section has unique structural characteristics as compared to the other sections, so that different sections will dominate as the Thomson coil's speed of operation varies.

A circuit breaker includes at least one moveable contact. The moveable electrode is operably connected to a Thomson coil actuator that can separate and open the contacts of the circuit breaker. A sensor senses current or voltage in the circuit breaker. When a condition exists that triggers an opening action, a controller will use select a current level to apply to the Thomson coil actuator. The selected current level will vary based on the sensed current or voltage level. The controller will cause a driver to apply the selected current level to the Thomson coil actuator, and it will cause the contacts to separate and open. If the circuit breaker is a vacuum interrupter, the vacuum interrupter may employ a multi-section bellows in which each section has unique structural characteristics as compared to the other sections, so that different sections will dominate as the Thomson coil's speed of operation varies.

Various embodiments of the teachings herein include a DC network comprising: an electrical conductor; a switching unit arranged at one end of the conductor to break the electrical connection via the conductor, the switching unit including a controllable power semiconductor connected in series in the current path of the conductor; wherein the conductor includes a first section and a second section starting from the switching unit with a connection point between the first section and the second section; a first overvoltage protection apparatus connected between the connecting point and a second pole of the DC network; and a second overvoltage protection apparatus connected between that end of the second section remote from the switching unit and the second pole. The overvoltage protection apparatuses each have a capacitor.

A DC voltage switch includes a first switch arranged at a first potential between a first terminal of the first switch and a second terminal of the first switch, a first discharging device which is arranged between the first terminal at the first potential and a third terminal at a second potential and includes a first switching element designed as a thyristor, and a second discharging device which is arranged between the second terminal and a fourth terminal at the second potential and includes a second switching element designed as a semiconductor switch that can be switched off. The respective discharging devices connect the first terminal and the third terminal and/or the second terminal and the fourth terminal, at least temporarily, when the DC voltage switch is being or has been switched off.

A contactor apparatus and method for operating the contactor apparatus can include a contactor assembly with a contactor coil operably coupled to a contactor switch. One or more sensors can be provided in the contactor assembly adapted to measure one or more aspects of the contactor assembly. Based upon the measured aspects, a controller can initiate operation of the contactor switch to effectively toggle the contactor switch at a zero-crossing point along an alternating current waveform.

Provided is an arc suppression device including one or more current-limiting circuits provided in parallel with a circuit breaker that switches between feeding and shutoff of power from a power supply. The current-limiting circuit shuts off a current from the power supply when the power from the power supply is fed to a load through a circuit breaker. The current from the power supply is shut off when a voltage generated by a potential difference between contacts of the circuit breaker becomes a predetermined voltage or higher in a case where feeding of the power from the power supply to the load is shut off by the circuit breaker. The potential difference is generated upon shutoff.

Provided is an arc suppression device including one or more current-limiting circuits provided in parallel with a circuit breaker that switches between feeding and shutoff of power from a power supply. The current-limiting circuit shuts off a current from the power supply when the power from the power supply is fed to a load through a circuit breaker. The current from the power supply is shut off when a voltage generated by a potential difference between contacts of the circuit breaker becomes a predetermined voltage or higher in a case where feeding of the power from the power supply to the load is shut off by the circuit breaker. The potential difference is generated upon shutoff.

A switching apparatus for conducting and interrupting electrical currents includes: a first mechanical contact arrangement; a semiconductor switch which is connected in parallel to the first mechanical contact arrangement; a second mechanical contact arrangement connected in series to the first mechanical contact arrangement; an auxiliary coil electrically isolated from a circuit of a switching drive used to move contacts of the first and second mechanical contact arrangements, and which is electromagnetically coupled to a coil of the switching drive such that a voltage is generated therein when a voltage supply of the switching drive is switched off; and a switching electronics for switching the semiconductor switch on and off, and which is supplied with the voltage generated in the auxiliary coil when the voltage supply of the switching drive is switched off. The switching electronics switches the semiconductor switch on and off multiple times according to a prespecified sequence.

A device is for opening or closing a DC circuit with at least one busbar. The device includes an electric switch for opening or closing the DC circuit; a fault current detector; a trigger unit and a precharging device. The electric switch opens the DC circuit via the trigger unit upon a fault current being detected by the fault current detector. Further, the precharging device restores the voltage on the busbar prior to closing the electric switch. The device further includes a control unit for automatically closing the electric switch after the pre-charging process.