A communication device for an electrical switching unit that includes an actuator driven by a control circuit. The communication device includes: a connector that can be connected to the control circuit, to receive a state signal sent by the control circuit and to receive an electrical power supply voltage supplied by the switching unit; a capacitor configured to be recharged from the power supply voltage received from the input connector when the state signal takes a predefined value; a bistable relay comprising a normally-open electrical contact connected to output terminals to form a dry electrical contact; and a pulse generator supplied by the capacitor and being configured to excite the bistable relay when the capacitor reaches a predefined level of charge.

A thermal hazard protection circuit for a transportation vehicle comprises an interruptible power circuit connected between a power source and load, and a failsafe circuit operative to permanently interrupt current flow under an overcurrent condition. The interruptible power circuit comprises a Positive Temperature Coefficient (PTC) component in series with bi-stable relay configured as a SPST switch. The failsafe circuit comprises a failsafe relay energized by current in the interruptible power circuit. An input of the failsafe relay is connected to the battery, and a normally closed (NC) output (not connected to the input so long as the failsafe relay is energized) is connected to a control input of the bi-stable relay that opens the SPST switch. In an overcurrent condition, the PTC component limits current flow, switching the failsafe relay input to its NC outputs, providing a control signal to open the SPST switch, rendering the interruptible power circuit non-conductive and isolating the load.

A power switch controller includes a condition detector, a zero crossing detector, a retimer, and a driver. The condition detector detects a change in a sense signal towards a first or second condition. The zero crossing detector detects zero crossings in an AC powerline signal. The power switch controller drives a latching relay that connects a load to powerlines. The power switch controller activates or deactivates the latching relay based on the sensed condition, and retimes activation and deactivation pulses to align the relay contact opening and closing times to coincide with the AC powerline zero crossings, compensating for contact travel times. The activation and deactivation pulses have a duration of max 20 ms, and an amplitude of at least 110% of the maximum sustainable voltage for the relay coil(s). A power-on reset deactivates the relay, aligned with a second AC zero crossing.

An industrial process field device includes an active component, a latching relay, a controller, a relay drive, and a reset circuit. The active component may be a sensor configured to sense a process parameter, or a control device configured to control a process of the industrial process. The controller is configured to generate a switch signal, and the relay drive is configured to set the latching relay in one of a set state and a reset state based on the switch signal. The reset circuit is configured to set the latching relay to the reset state in response to an interruption of electrical power to the relay drive.

A power supply system comprises an AC input, an AC output, and a DC input; a DC intermediate circuit; a first converter connected, via a first bistable switching circuit, between the AC input and the DC intermediate circuit; a second converter connected, via a second bistable switching circuit, between the DC intermediate circuit and the AC output; a third converter connected, via a third bistable switching circuit, between the DC input and the DC intermediate circuit; a bypass circuit connected, via a bypass bistable switching circuit, between the AC input and the AC output and configured to provide a bypassing path from the AC input to the AC output; and a control unit.

A power relay for a vehicle is disclosed. The power relay has a housing formed by a connector base and a housing can set thereon, two connection bolts being inserted into the connector base for contacting a load circuit. The power relay further has a coil subassembly arranged in the housing and containing a solenoid coil and an armature. The armature is coupled by a force-transmission member to a contact bridge and can shift in the housing, under the effect of a magnetic field generated by the solenoid coil, in such a way that the contact bridge can be reversibly moved between a closing position, in which the contact bridge bridges the connection bolts in an electro conducting manner, and an opening position, in which the contact bridge is not in contact with the connection bolts. The housing can is configured as an injection-molded component made of plastic.

A control circuit and method for a single coil magnetic latching relay is provided in the present disclosure. The circuit includes: a first control circuit (21) and a first single coil magnetic latching relay coil (22). The first control circuit (21) includes: a first transistor (211), a first diode (212), a second diode (213), a first capacitor (214), a second capacitor (215), a first resistor (216) and a second resistor (217) and the first control circuit (21) is configured to control the first single coil magnetic latching relay coil (22) to enter a preset state and/or maintain the preset state.

A latching relay includes a first coil, a second coil and a common plunger operatively connected between the first and second coils such that activation of the first coil moves the plunger to a first position and activation of the second coil moves the plunger to a second position. The latching relay also includes a limit switch having a common contact and first and second coil contacts. A position of the common contact is alternately switched between electrical connection to either the first or second coil contact based on a position of the plunger. The first and second coil contacts are electrically connected to the first and second coils, respectively such that when electrical power is applied to the common contact, the electrical power is alternately applied to either the first coil or the second coil depending on the position of the common contact.

Provided herein is an improved bi-stable relay operable with a relay control circuit including a boost converter and an energy storage device, which is used to switch the bi-stable relay. In some embodiments, the bi-stable relay includes a solenoid wound with multiple coil windings. A conductive plate (e.g., a bus bar) may be coupled to a plunger of the solenoid, and is provided with contacts on each end of the conductive plate. The conductive plate is configured to electrically engage and disengage the solenoid upon respective application of power to the solenoid. The control circuit causes the solenoid to remain in an open position when selectively energized by a pulse for moving and retaining the conductive plate of the plunger against the solenoid for allowing wide operating voltage and reduced operating power.

Disclosed herein is a device comprising a pulse trigger switch module configured to generate a first control signal in response to a first input signal value and generate the second control signal in response to a second input signal value. An on pulse generator module provides a first pulse signal having a first predetermined pulse duration in response to the first control signal and an off pulse generator module provides a second pulse signal having a second predetermined pulse duration in response to the second control signal. An on pulse switch module connects a power signal to an output in response to the first pulse signal and an off pulse switch module connects the power signal to the output in response to the second pulse signal.