The present disclosure illustrates an electromagnetic relay device and a control method thereof. In the electromagnetic relay device, a control circuit respectively provides driving power to switch on the two electromagnetic relay units disposed adjacent to each other, and then provides the first holding power and the second holding power, lower than the driving power, to the two electromagnetic relay units after the two electromagnetic relay units are switched on, thereby maintaining the two electromagnetic relay units in the switched-on status. When the electromagnetic relay unit receiving the second holding power is tripped because of the environmental factor, the electromagnetic relay unit receiving the second holding power generates and outputs the trip feedback signal to the control circuit, so that the control circuit increases the first holding power upon receipt of the trip feedback signal. The second holding power is lower than or equal to the first holding power.

A thermal control process for an electronic power device including a multi junction integrated circuit may include defining a first and at least one second groups of junctions, with each group including one first and at least one second junctions, and associating a thermal detector with each group. A first group control may be executed which detects group electric signals representative of the temperature detected by the thermal detectors, processes the group electric signals with reference to a group critical thermal event, identifies a critical group when the corresponding group electric signal detects the critical group thermal event, and generates group deactivating signals suitable for selectively deactivating the first and the at least one second junctions of the identified critical group with respect to the remaining junctions of the integrated circuit.

A PCB motor controller comprises relays mounted on a PCB and interconnected to power traces in or on the PCB to receive incoming three-phase power and to output three-phase power to a motor. Control power traces in or on the PCB connect the relays to control circuitry, also mounted on the PCB. A power supply is mounted on the PCB and connected to the control circuitry to provide power for its operation and for switching of the relays. The relays are switched in accordance with a point-on-wave (POW) switching scheme, allowing for the use or relays and the PCB, which may not otherwise be suitable for motor control applications.

One embodiment describes a method that includes determining, using a control circuitry, temperature of a switching device before a make operation by applying a measurement current to an operating coil of the switching device, wherein the measurement current is insufficient to make the switching device; and determining voltage at the operating coil when the measurement current is applied, in which the voltage at the operating coil is directly related to the temperature. The method further includes determining, using the control circuitry, when to apply a pull-in current to the operating coil to close the switching device based at least in part on the voltage at the operating coil, such that the switching device makes at a desired time.

One embodiment describes a tangible, non-transitory, computer-readable medium storing instructions executable by a processor of an operating coil driver circuitry. The instructions include instructions to instruct a switch to supply a specific current to an operating coil of a switching device using a pulse-width modulated signal; determine duty cycle of the pulse-width modulated signal; and determine wellness of the switching device based at least in part on the duty cycle of the pulse-width module signal.

One embodiment describes a tangible, non-transitory, computer-readable medium storing instructions executable by a processor of an operating coil driver circuitry. The instructions include instructions to instruct a switch to supply a specific current to an operating coil of a switching device using a pulse-width modulated signal; determine duty cycle of the pulse-width modulated signal; and determine wellness of the switching device based at least in part on the duty cycle of the pulse-width module signal.

A switch device includes a phase change switch and a memory for storing a target state of the phase change switch. A controller determines a phase state of the phase change switch, and, if the state of the phase change switch does not correspond to the target state, controls a heater of the phase change switch to change the state of the phase changes switch to the target state.

A circuit and method for controlling a voltage applied to a coil to actuate electromechanical relays or contactors. The strength of a magnetic field operating the coil is a function of the product of the number of turns of the coil wire and the magnitude of current, in amperes, passing through the coil wire. An adjustable voltage regulator provides a regulated voltage as an output to a first terminal of a coil to energize the coil based on the temperature of the coil as sensed by a temperature sensing device located proximate the coil. The regulated voltage is controlled based on the sensed coil temperature to consistently provide a current of optimal magnitude to actuate the coil at the sensed temperature. A transient voltage suppression circuit may be used with the coil to suppress back electromotive force generated currents and voltages when the coil is de-energized.

A circuit and method for controlling a voltage applied to a coil to actuate electromechanical relays or contactors. The strength of a magnetic field operating the coil is a function of the product of the number of turns of the coil wire and the magnitude of current, in amperes, passing through the coil wire. An adjustable voltage regulator provides a regulated voltage as an output to a first terminal of a coil to energize the coil based on the temperature of the coil as sensed by a temperature sensing device located proximate the coil. The regulated voltage is controlled based on the sensed coil temperature to consistently provide a current of optimal magnitude to actuate the coil at the sensed temperature. A transient voltage suppression circuit may be used with the coil to suppress back electromotive force generated currents and voltages when the coil is de-energized.

One embodiment describes a method that includes determining, using a control circuitry, temperature of a switching device before a make operation by applying a measurement current to an operating coil of the switching device, wherein the measurement current is insufficient to make the switching device; and determining voltage at the operating coil when the measurement current is applied, in which the voltage at the operating coil is directly related to the temperature. The method further includes determining, using the control circuitry, when to apply a pull-in current to the operating coil to close the switching device based at least in part on the voltage at the operating coil, such that the switching device makes at a desired time.