A driving circuit includes a relay driver for selectively connecting a relay coil with (a) a first current path between the relay driver and a relay voltage input or (b) a second current path between the relay driver and a ground connection. Another relay driver selectively connects the coil with (a) a third current path between the other relay driver and the relay voltage input or (b) a fourth current path between the other relay driver and the ground connection. The relay drivers may connect the coil between the second and third current paths for latching the relay, and between the first and fourth current paths for unlatching the relay. The driving circuit applies signals of opposite polarity and different magnitudes through the coil to latch and unlatch the relay. The signal for unlatching can be of lower voltage than the signal for latching the relay.

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.

A latching solenoid (100, 200, 300) includes a coil (114) and an armature (120). The armature (120) moves between latch position and a rest position in response to momentary energization of the coil (114) without moving in response to de-energization of the coil (114). A solenoid controller (140) is operable to receive messages from a vehicle bus (108, 410) and output control signals that cause energization of the coil (114).

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.

A process for automated contact wetting in a sensor circuit includes generating a first current through a contact by sequencing a first circuit on, the first current exceeding a wetting threshold of the contact, and reducing current through the contact to a second current by sequencing a second circuit on, the second current being below the wetting threshold.

An output-switch control system for an AC-DC power supply includes a push-button switch that has two triggers. The triggers correspond to different contacts of a detecting circuit, respectively. When the push-button switch is pressed to make the triggers and the contacts turn into a close-circuit state form an open-circuit state, the detecting circuit outputs a power-source-on signal, and when the push-button switch is pressed again, and either of the triggers and the contact turn into the close-circuit state form the open-circuit state, the detecting circuit outputs a power-source-off signal immediately. With the dual-transition signal certification at the contacts, safe output-switch control can be achieved, so as to provide a user with operational safety.

An automatic transfer switch includes a first phase switch component having a first plurality of cassettes, and at least one outer bus component disposed at an outer side of the first phase switch component. The automatic transfer switch additionally includes a first plate which is disposed on the outer side of the first phase switch component at a terminal end of the first phase switch component. The first plate is structured to increase impedance on an outer bus component of the first phase switch component to rebalance current along the first phase switch component.

The disclosure concerns a switched-mode power supply comprising a module for charging and discharging an energy store including an electrical transformer. The device provides high configuration flexibility.

A semiconductor integrated circuit includes: a first wire through which a signal is transmitted; a second wire that is not used for signal transmission; a switch that creates or breaks an electric connection between the first wire and the second wire; and a control circuit that controls the switch according to an potential of the signal, which is transmitted through the first wire, so that part of charge stored in a first wire capacitor of the first wire moves to a second wire capacitor of the second wire and is stored in the second wire capacitor and the charge stored in the second wire capacitor are drawn to the first wire capacitor to charge the first wire capacitor.