An automatic transfer switch (ATS) includes a controller in communication with first and second relays via power line carrier (PLC) communications.

A safety circuit for fail-safe shutdown of a dangerous technical system with a plurality of disconnectable system component groups comprises a plurality of safety switching devices electrically connected to one another in series to form a closed-loop monitoring circuit in which electric monitoring current flows through the safety switching devices. Each of the safety switching devices includes: a fail-safe control unit that detects and evaluates information about a current operating state of any system component group assigned to it; and a current flow adjuster that changes the current flow within the monitoring circuit to interrupt the monitoring circuit in response to detection of a safety command by the safety switching device. The fail-safe control units generate a shutdown signal in response to an interruption of the current flow within the monitoring circuit, which causes the fail-safe shutdown of any of the system component group not already shut down.

A relay fault diagnosis device includes: at least one C-contact relay that has a common terminal, a normally open terminal and a normally closed terminal; a read-back circuit that is connected to the normally closed terminal of the relay; and a diagnostic section that outputs a test signal to the common terminal to diagnose a fault in the relay.

A safety switching device for switching on and safely switching off an electrical load, comprising a failsafe evaluation/control unit, an output terminal for providing a potential, a switching element having a first working contact, wherein the potential is connectable to the output terminal via the first working contact, and an input terminal for receiving an input signal for operating the switching element via the evaluation/control unit. Additionally, the safety switching device comprises a separator having a connecting piece, a drive element and a separating element. The drive element is configured to mechanically move the separating element from a first position into a second position and the connecting piece and the first working contact electrically connect in series with one another the potential to the output terminal. Further, in the second position the separating element irreversibly separates the connecting piece into two pieces.

A safety circuit coupled between a first direct current (DC) circuit and a second DC circuit, wherein the first DC circuit supplies power to the second DC circuit. The safety circuit comprises a first series connection between positive poles of the first and second DC circuits (the first series connection comprising a first diode, a second diode and a first controllable switch), a second series connection between negative poles of the first and second DC circuits (the second series connection comprising a third diode, a fourth diode and a second controllable switch), a first energy storage device (coupled between the positive pole of the second DC circuit and the first terminal of the second controllable switch), and a second energy storage device (coupled between the negative pole of the second DC circuit and the first terminal of the first controllable switch). The safety circuit further comprises a first feedback circuit for indicating an active state of the first controllable switch and a second feedback circuit for indicating an active state of the second controllable switch.

A circuit breaker includes contacts movable between a closed position wherein a line terminal and a load terminal are in electrical communication, and an open position wherein the line and the load terminals are electrically isolated. A primary trip coil and a secondary trip coil are connected to the contacts, each causing the contacts to move from the closed position to the open position when activated, thereby tripping the breaker. A monitoring circuit, upon a determination being made that the breaker is not operating within acceptable trip parameters, causes activation of the primary coil, and, upon a determination being made that the breaker is not operating within acceptable disable parameters, causes activation of the secondary coil. The breaker is user resettable if the breaker has been tripped by the primary trip coil, but is not user resettable if the breaker has been tripped by the secondary trip coil.

A relay arrangement includes at least two series-connected relays, which are mechanically and electrically connected to a main printed circuit board via first terminals and second terminals, and at least one flat conductor for conducting current between the at least two series connected relays. The flat conductor is mechanically connected to the main printed circuit board and electrically and thermally connected to the first terminals of the relays, and the at least one flat conductor is configured to dissipate heat produced during operation of the relays.

A relay circuit and a method for performing a self-test. The relay circuit has four relays, each relay having a first forcibly guided contact and a second forcibly guided contact. The four relays are arranged in a first and a second pair of two in series connected first forcibly guided contacts. The first and second relay pair are arranged in parallel between a power supply connection and a load connection for switching a power supply to a load through the first forcibly guided contacts. Such a relay circuit enables supplying power via one of the relay pairs, while cutting power via the other relay pair, which facilitates testing of the relay pair which has cut power without interrupting the process supervised by the Safety Instrumented System which the relay circuit forms part of.

According to one embodiment of the present invention, a charging device for an electric vehicle can comprise: a relay unit arranged between an inlet and a battery so as to enable an output voltage of the inlet to be provided to the battery; a first voltage sensing unit for sensing the output voltage of the inlet; a second voltage sensing unit for sensing an output voltage of the relay; and a relay control unit for receiving output signals of the first voltage sensing unit and the second voltage sensing unit, and determining whether the sensed voltages are voltages within a normal range so as to control the ON/OFF of the relay unit.

A relay. The relay includes a housing and a microelectromechanical (MEMS) component having a MEMS switch that can be switched between two stable states. The relay further comprises an application-specific integrated circuit (ASIC) component which, along with the MEMS component, is arranged in the housing. The ASIC component is configured to control the MEMS switch and/or to monitor a functionality of the MEMS switch.