A switch system includes a system main relay, a temperature measuring unit, and a controller. The system main relay is configured to electrically connect a battery and an onboard device to each other by turning on a contact point, and to electrically disconnect the battery and the onboard device by turning off the contact point. The temperature measuring unit is configured to measure temperature of the contact point of the system main relay. The controller is configured to cause the system main relay to repeatedly turn on and off the contact point at a predetermined timing, (i) when the temperature of the contact point of the system main relay is a predetermined temperature or more or (ii) when an amount of rise in the temperature of the contact point is a predetermined amount or more.

A circuit and a method for shutdown of automatic ignition controls upon valve relay failures. One or more embodiments describe a method including controlling a power supply to a valve by a valve drive circuit, the valve drive circuit comprising a first relay coil and a second relay coil. The method also includes controlling the valve drive circuit by checking the first relay coil and the second relay coil and issue a drive signal to the first relay coil and the second relay coil. The method further includes protecting from accidental supply of power by a protection switch based on the drive signal issued by the controller.

An apparatus is for a process machine having a process-status switch and a process-control element. The apparatus includes a sensor input signal conditioning circuit, a logic circuit and a power output circuit. The sensor input signal conditioning circuit is configured to provide a logic-converted status signal representing a process-status signal associated with the process-status switch of the process machine. The logic circuit is configured to provide a latched output signal converted from the logic-converted status signal provided by the sensor input signal conditioning circuit. The latched output signal has any one of a first latched state and a second latched state. The power output circuit is configured to execute any one of maintaining and disconnecting a voltage being applied to the process-control element depending on the state of the latched output signal.

The disclosure relates to an electromagnetic relay that comprises a yoke and an armature. The armature may be swivellably arranged on the yoke, have an open position and a contact position in relation to the yoke, and configured to be attracted by a magnetic field out of the open position into the contact position. The armature may include a first branch circuit having a first capacitor and a first exciter coil connected in series with the first capacitor, a second branch circuit having a second capacitor and a second exciter coil connected in series with the second capacitor, and a switch element arranged between the first branch circuit and the second branch circuit and having a first switch state and a second switch state. The first exciter coil and the second exciter coil may provide the magnetic field for attracting and retaining the armature.

A contact monitoring unit is for a safety-critical triggering apparatus of a switching device, including a connection diagram arranged on a first circuit carrier medium for a triggering apparatus and triggering electronics arranged on a second circuit carrier medium. The contact monitoring unit includes redundant electrical connections that are monitored such that, even a failure of a redundant electrical connection is detected.

A solenoid actuator for an injection valve or an intake valve is driven with current control during closed-loop control phases. In between the closed-loop current control, the actuator must be clamped to an opposite voltage so as to quickly decrease the current through the solenoid. The current is measured immediately following the clamping phase so as to determine whether or not the clamping phase resulted in the correct current level. If the measured current indicates an extraneous reduction in the current, the clamping phase duration is shortened for the next activation of this clamping phase. If the measured current indicates an insufficient decrease, the clamping phase duration is lengthened for the next following activation cycle.

A method for determining the operating status of a MV switching device (1), which comprises one or more electric poles, each comprising a movable contact and a fixed, contact adapted to be coupled or uncoupled during the switching operations of said switching device, and an electromagnetic actuator comprising a magnetic core, a test coil wound around said magnetic core and a movable plunger operatively coupled to the movable contact of each electric pole. The method comprises: providing a test signal (ST) to said test coil for an observation period of time (T.sub.O), said test signal having a waveform adapted to excite said magnetic core; obtaining measuring data (V.sub.M, I.sub.M) indicative of the voltage at the terminals of said test coil and of the current circulating along said test coil during said observation period of time; calculating observation data (R.sub.N, I.sub.M) indicative of the electric behaviour of said test coil at the end of said observation period of time on the base of said measuring data; selecting at least a transformation function (F.sub.1, F.sub.2) indicative of the electromagnetic behaviour of said electromagnetic actuator; and calculating first estimation data (P, T) indicative of the operating status of said electromagnetic actuator on the base of said observation data (R.sub.N, L.sub.N) by using said transformation function, said first estimation data comprising, a first estimation value (P) indicative of the position of the movable plunger of said electromagnetic actuator.

There is a need to monitor and control the state of relays and circuit breakers within power distribution systems. The monitoring of a relay state, i.e. open or closed, is often performed by applying a monitoring signal to sensing contacts added to the relay. Manufactures of such systems have chosen many different voltages for their own. monitoring systems making it difficult to interconnect dissimilar monitoring systems. A signal conditioning circuit is provided that can cope with a large input voltage range and can be configured to allow may items of equipment(which may be new item or legacy items) to be connected to a controller.

A sensor connecting unit includes a safety input for connecting with a sensor; a power supply that is controllable through a controllable power switch; and a first I/O processing unit and a second I/O processing unit being connected to each other through a reciprocal comparison communication channel. The first I/O processing unit and the second I/O processing unit are both connected through a measurement circuit to measure voltage, current or power between a reference input and the safety input, and connected to a safety bus. The first I/O processing unit informs the second I/O processing unit about switching off of the controllable power supply, the second I/O processing unit commands the first I/O processing unit to switch off the controllable power supply, and/or the second I/O processing unit measures an output of the controllable power switch to detect switching of the power switch.

A fail-safe circuit enables a switch to turn on/off according to a signal from an external device if a microcomputer that controls the turning on/off of the switch falls into an abnormal state and is reset, and if the power supply for a circuit that backs up the control of the switch is lost. The fail-safe circuit includes a microcomputer that controls the turning on/off of a switch based on an instruction signal from an input terminal, a watchdog circuit that generates a reset signal based on a watchdog pulse from the microcomputer, and a transistor for masking a watchdog pulse for resetting a flip-flop circuit that is set by the reset signal. If a voltage supplied by a power supply circuit is lost, a transistor turns off, and therefore the switch turns on/off according to an instruction signal supplied to an output terminal via a resistor and a diode.