A method may include receiving a command to move one or more armatures configured to move between a first position that electrically couples one or more first movable contacts to one or more second contacts and a second position that electrically uncouples the one or more first movable contacts from the one or more second contacts. The method may also include determining an operating frequency of the system, dynamically determining an open-before-zero target point associated with the operating frequency, and transmitting a command to the switching device to move the one or more armatures from the first position to the second position at the open-before-zero target point to normalize the arc energy over the operating frequency range.

A relay control apparatus and method for retaining a relay in a closed state even though a system error occurs to reset the processor. Therefore, the relay control apparatus and method prevents an accident caused by the reset of the processor since the operation state of a plurality of relays is maintained even when the processor is reset. In addition, if the operation state of the processor is a reset state even after a predetermined time passes, the operation state of the plurality of relays is changed to a turn-off state, and system resources and energy are prevented from being wasted. In addition, when the operation state of the processor is recovered, the operation state of the plurality of relays may be controlled by the processor.

A relay control apparatus and method for retaining a relay in a closed state even though a system error occurs to reset the processor. Therefore, the relay control apparatus and method prevents an accident caused by the reset of the processor since the operation state of a plurality of relays is maintained even when the processor is reset. In addition, if the operation state of the processor is a reset state even after a predetermined time passes, the operation state of the plurality of relays is changed to a turn-off state, and system resources and energy are prevented from being wasted. In addition, when the operation state of the processor is recovered, the operation state of the plurality of relays may be controlled by the processor.

Circuitry for controlling relay activation timing is described. The circuitry includes voltage zero cross detection circuitry configured to produce a zero cross detection signal indicating a zero cross time of an alternating current (AC) signal. The circuitry also includes current measuring circuitry coupled to voltage zero cross detection circuitry. The current measuring circuitry is configured to produce a current flow detection signal indicating a current flow start time of the AC signal. The circuitry further includes relay circuitry coupled to the current measuring circuitry. The circuitry additionally includes a processor coupled to the voltage zero cross detection circuitry, to the current measuring circuitry, and to the relay circuitry. The processor is configured to determine a relay time error based on the zero cross time and the current flow start time. The processor is also configured to control relay activation signal timing to reduce the relay time error.

Circuitry for controlling relay activation timing is described. The circuitry includes voltage zero cross detection circuitry configured to produce a zero cross detection signal indicating a zero cross time of an alternating current (AC) signal. The circuitry also includes current measuring circuitry coupled to voltage zero cross detection circuitry. The current measuring circuitry is configured to produce a current flow detection signal indicating a current flow start time of the AC signal. The circuitry further includes relay circuitry coupled to the current measuring circuitry. The circuitry additionally includes a processor coupled to the voltage zero cross detection circuitry, to the current measuring circuitry, and to the relay circuitry. The processor is configured to determine a relay time error based on the zero cross time and the current flow start time. The processor is also configured to control relay activation signal timing to reduce the relay time error.

A relay control apparatus and method for retaining a relay in a closed state even though a system error occurs to reset the processor. Therefore, the relay control apparatus and method prevents an accident caused by the reset of the processor since the operation state of a plurality of relays is maintained even when the processor is reset. In addition, if the operation state of the processor is a reset state even after a predetermined time passes, the operation state of the plurality of relays is changed to a turn-off state, and system resources and energy are prevented from being wasted. In addition, when the operation state of the processor is recovered, the operation state of the plurality of relays may be controlled by the processor.

A relay control apparatus and method for retaining a relay in a closed state even though a system error occurs to reset the processor. Therefore, the relay control apparatus and method prevents an accident caused by the reset of the processor since the operation state of a plurality of relays is maintained even when the processor is reset. In addition, if the operation state of the processor is a reset state even after a predetermined time passes, the operation state of the plurality of relays is changed to a turn-off state, and system resources and energy are prevented from being wasted. In addition, when the operation state of the processor is recovered, the operation state of the plurality of relays may be controlled by the processor.

Circuitry for controlling relay activation timing is described. The circuitry includes voltage zero cross detection circuitry configured to produce a zero cross detection signal indicating a zero cross time of an alternating current (AC) signal. The circuitry also includes current measuring circuitry coupled to voltage zero cross detection circuitry. The current measuring circuitry is configured to produce a current flow detection signal indicating a current flow start time of the AC signal. The circuitry further includes relay circuitry coupled to the current measuring circuitry. The circuitry additionally includes a processor coupled to the voltage zero cross detection circuitry, to the current measuring circuitry, and to the relay circuitry. The processor is configured to determine a relay time error based on the zero cross time and the current flow start time. The processor is also configured to control relay activation signal timing to reduce the relay time error.

Circuitry for controlling relay activation timing is described. The circuitry includes voltage zero cross detection circuitry configured to produce a zero cross detection signal indicating a zero cross time of an alternating current (AC) signal. The circuitry also includes current measuring circuitry coupled to voltage zero cross detection circuitry. The current measuring circuitry is configured to produce a current flow detection signal indicating a current flow start time of the AC signal. The circuitry further includes relay circuitry coupled to the current measuring circuitry. The circuitry additionally includes a processor coupled to the voltage zero cross detection circuitry, to the current measuring circuitry, and to the relay circuitry. The processor is configured to determine a relay time error based on the zero cross time and the current flow start time. The processor is also configured to control relay activation signal timing to reduce the relay time error.

Methods, devices, and systems for synchronizing switching times of relays to a zero-crossing are described herein. One device includes a memory, and a processor configured to execute executable instructions stored in the memory to receive phase information of an alternating-current (AC) electric mains, determine, from the phase information, a zero-crossing of the phase of the AC electric mains, determine a reference time based on the zero-crossing for a number of relays corresponding to a number of relay controllers, and transmit the reference time to the number of relay controllers.