A switch failure diagnosis device for using in a current path between an electric device and an electric storage device includes plural switches, a switch terminal voltage detector, and a controller. The switches are connected parallel to each other in the current path. The switch terminal voltage detector outputs a switch terminal voltage detection signal. The controller is configured to select the switches at different time in sequence and input an open instruction signal to each switch at the time when the switch is selected, and to determine, based on the switch terminal voltage detection signal output while the open instruction signal is given, that at least one of the switches has a failure if the detected voltage is in a failure determination range.

A wireless checking system of a switch and operation unit that are provided in a vehicle includes: a switch disposed at a predetermined location in the vehicle; an operation unit wirelessly connected with the switch and disposed at a predetermined location in the vehicle to be operated by the switch; and a diagnosis equipment wirelessly connected with each of the switch and the operation unit and configured to wirelessly operate the switch and the operation unit, detect an operation state of the switch and the operation unit, and diagnose a wireless connection state of the switch and the operation unit.

A method for diagnosing an operating state, i.e., wear, of a contactor which includes a processing unit directing voltage control means; an, actuating coil; means for measuring an electric characteristic of the actuating coil; and a diode in parallel with the coil and the measuring means; the method including creating, for a specific contactor design, a plurality of variation curves of an electric characteristic of the coils of such contactors, over a drop-out period, by testing said contactors by sending a drop-out order fixing a drop-out voltage across the coil; after the drop-out order, repeatedly measuring the electric characteristic of the coil during a drop-out period; later sending a diagnostic drop-out order fixing the same drop-out voltage across the terminals of an actuating coil of a subject contactor being diagnosed; then measuring the same electric characteristic of the subject coil during a drop-out period; identifying a measured value of that characteristic of the subject coil, then comparing that measured value with the variation curves of the plurality of contactors of the same design, thereby diagnosing a state of wear of the subject contactor.

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 method is disclosed for testing a latching magnet of a switch including a switching contact, formed from contact elements mechanically separated from one another for opening the switching contact; an electronic trip unit, to monitor current flowing via the contact elements and to perform a test for a current-dependent trip condition; an electrical energy store, forming a circuit with the winding of the latching magnet, the circuit being closed for a first closing time when the trip condition of the trip unit is met; and an actuator, actuable by closing off the circuit and configured to separate the contact elements. For test purposes, the circuit is closed for a second closing time, which is so short that separation of the contact elements by the actuator does not take place. A test is then performed to ascertain whether there is a current flowing via the winding of the latching magnet.

One embodiment describes a three-phase electromechanical switching device, which includes three single-phase switching devices mechanically and electrically coupled in parallel with one another, each single-phase switching device including a direct current electromagnetic operator that in operation receives a direct current control signal for switching of the device, stationary contacts disposed in a respective device housing, and a movable assembly that in operation is displaced by energizing the operator and that include movable contacts that open and close, with the stationary contacts, a single current carrying path through the respective single-phase switching device; in which each of the single-phase switching devices receives control signals from control circuitry coupled to the operators of the respective single-phase switching devices to cause at least one of the single-phase switching devices to open or close the single current carrying path at a desired time coordinated with a current zero-crossing or a predicted current zero-crossing of a phase of three-phase power.

A diagnostic system for a voltage regulator is provided. The diagnostic system includes a microcontroller having first and second analog-to-digital converters and first and second output ports. The first analog-to-digital converter outputs a first voltage value corresponding to the first voltage from the voltage regulator. The microcontroller executes a first diagnostic function to set a first voltage regulator diagnostic flag equal to a fault value indicating a voltage out of range condition, if the first voltage value is greater than a first threshold voltage value or the first voltage value is less than a second threshold voltage value. The microcontroller executes a second diagnostic function to stop generating first and second control signals to de-energize a contactor coil to open a contact of a contactor if the first voltage regulator diagnostic flag is equal to the fault value.

An automatic transfer switch (100) for automatically switching an electrical load between two power sources is provided. Two power cords (106) enter the ATS (A power and B power inputs) and one cord (109) exits the ATS (power out to the load). The ATS has indicators (107) located beneath a clear crenelated plastic lens (108) that also acts as the air inlets. The ATS (100) also has a communication portal (103) and a small push-button (104) used for inputting some local control commands directly to the ATS (100). The ATS (100) can be mounted on a DIN rail at a rack and avoids occupying rack shelves.

The magnetic coil driving circuit of the magnetic contactor according to the present invention comprises a semiconductor switch configured to open or close a circuit for magnetizing or demagnetizing a magnetic coil; a pulse width modulation unit configured to output a pulse signal as a control signal for turning on or off the semiconductor switch; a control unit configured to output a control signal for changing a pulse width of the pulse signal to the pulse width modulation unit; and a temperature detection and protection unit configured to detect a temperature inside the magnetic contactor, output an output signal for turning off the semiconductor switch when the temperature exceeds an allowable temperature, and control the semiconductor switch by the pulse signal from the pulse width modulation unit when the temperature is within the allowable temperature.

Embodiments of this application relate to the field of electricity, and disclose a drive circuit. In some embodiments of this application, the drive circuit includes a low-side driver module and a delay module, the delay module is configured to output a delay signal of preset duration to the low-side driver module in a case that a control module is being reset; and the low-side driver module is configured to: according to on the delay signal of preset duration, maintain a first state within the preset duration, the first state being the same as a second state; where the second state is a working state of the low-side driver module before the control module is reset, and the second state includes being on or off. The embodiments can help avoid safety hazards caused by unexpected disconnection of a drive signal of the control module.