Embodiments of the present disclosure relate to a control circuit for a contactor and a control method thereof. The control circuit comprises: a pulse converter configured to convert a turn-on control signal into a continuous pulse signal; a first controller configured to generate a first breaking control signal at a first time in response to detection of the disappearance of the continuous pulse signal received from the pulse converter; a second controller configured to generate a second breaking control signal at a second time in response to detection of the disappearance of the continuous pulse signal received from the pulse converter, wherein the first time is earlier than the second time; and a coil driver configured to turn off a current of the excitation coil according to the received first breaking control signal, and if the current is not turned off according to the first breaking control signal, to further turn off the current of the excitation coil according to the second breaking control signal, thereby realizing the breaking of the main contact.

A safety switching device for fail-safely disconnecting an electrical load has an input part for receiving a safety-relevant input signal, a logic part for processing the at least one safety-relevant input signal, and an output part. The output part has a relay coil and four relay contacts. The first and second relay contacts are arranged electrically in series with one another. The third and fourth relay contacts are also arranged electrically in series with one another. The first and the third relay contacts are mechanically coupled to each other and form a first group of positively driven relay contacts. The second and the fourth relay contacts are mechanically coupled to each other and form a second group of positively driven relay contacts. The logic part redundantly controls the first and the second groups of positively driven relay contacts to selectively allow, or to interrupt in a fail-safe manner, a current flow to the electrical load, depending on the safety-relevant input signal. The relay coil is electromagnetically coupled to the first and second groups of positively driven relay contacts so that the logic part can control the relay contacts together via a single relay coil.

In order to specify a method, which is improved in comparison to the prior art, for monitoring an electrical switching arrangement having at least two channels, which each electrically conductively connect an electrical source supplying the respective channel, forming an electrical supply quantity, to an output of the respective channel, the switching arrangement is fed not only an external safety signal, from which an internal safety signal is respectively generated for the at least two channels in order to therewith control a voltage interrupter connected in series in the respective channel, but also a pulsed diagnostic signal, which is superimposed on the internal safety signals in order to alternately open and close again the voltage interrupters connected in the respective channels and to thus respectively alternately interrupt the supply quantities appearing in the respective channels.

A battery safety device for a vehicle and a method of detecting failure thereof is installed between a high-voltage battery mounted on the vehicle and a power line. The device includes a first main relay connected to a positive terminal of the battery in series, and a second main relay connected to a negative terminal of the battery in series. A capacitor is connected in parallel to the first main relay and connected to the positive terminal of the battery.

The invention relates to a safety switching device (10) comprising a control side (40) with at least one single-error tolerance, having a first and second control unit (12, 14), each formed on an actuation side (50) for emitting a switch command (20) to at least two switching elements (52, 54, 56), and comprising a monitoring unit (30, 30.1, 30.2, 30.3) having a first and a second connection element (31, 36), and which monitoring unit (30, 30.1, 30.2, 30.3) is designed to emit the switch command (20) to at least one switching element (52, 54, 56) of a load circuit (23), characterised in that the at least two switching elements (52, 54, 56) are each designed as standard components that are free from a forced guidance of the contacts (62) thereof, and the first connection element (31) is directly connected to the second control unit (14) via a first feedback channel (42) and the second connection element (36) is directly connected to the first control unit (12) via a second feedback channel (44).

A protected switch includes first and second electromechanical relays with guided contacts, each including an electromagnet and electrical contacts. A first contact of the first relay and a first contact of the second relay are connected in series in order to form a switching circuit. The switch further includes an interconnection circuit which connects at least a portion of the other electrical contacts of the first and second relays. The excitation of the first electromagnet is conditional on the state of the second relay and the excitation of the second electromagnet is conditional on the state of the first relay.

An image forming system comprises a first housing, a second housing and a third housing. The second housing may comprise a motor, a first door and a first switch. The first switch is provided on an electrical path connecting a power supply and the motor, for switching between a first state and a second state and for switching from the first state to the second state. The third housing may comprise a load. When the first door is opened in a state where the first switch is in the first state, the first switch switches from the first state to the second state to cause supply of electric power to the load to be cut off.

An image forming system comprises a first housing, a second housing and a third housing. The second housing may comprise a motor, a first door and a first switch. The first switch is provided on an electrical path connecting a power supply and the motor, for switching between a first state and a second state and for switching from the first state to the second state. The third housing may comprise a load. When the first door is opened in a state where the first switch is in the first state, the first switch switches from the first state to the second state to cause supply of electric power to the load to be cut off.

A charging control device including: a first and second electrode supply path; a voltage measurement circuit configured to measure a voltage between the first and second electrode side supply paths; a first and second electrode side relays on the first and second electrode side supply paths which are located closer to the battery than the voltage measurement circuit; a series circuit of a resistor and a resistance regulation relay, the series circuit being connected in parallel to the voltage measurement circuit; and a controller configured to control opening and closing the first electrode side relay, the second electrode side relay and the resistance regulation relay, wherein the controller is configured to control the resistance regulation relay to be closed when performing welding determination of the first electrode side relay and/or the second electrode side relay.

A relay control apparatus for a relay including a contact connected between a positive electrode of a battery and a load, and a coil connected between a relay power terminal and a ground in which the contact moves to a closed position when the coil is energized. The relay control apparatus includes a coil control switch which is turned on in response to a first switching signal having a voltage level that is equal to or higher than a first threshold voltage in response to a relay on-command, and a relay holding circuit configured to store emergency power using power supplied from the battery.