The present disclosure relates to a relay module including a control input for combined control and power supply of the relay module with alternating voltage. A fixed voltage controller of the relay module generates a fixed voltage after rectification of the alternating voltage or a portion of the alternating voltage. A comparator is operated by the fixed voltage and derives a reference voltage from the fixed voltage. The comparator compares a rectified and smoothed portion of the alternating voltage with the reference voltage. A switching step of the relay module operates a relay unit according to the comparison of the comparator, which relay unit is connected on the input side to the switching step and on the output side to switch connections of the relay module.

A control device for power supply time of timers comprises an alternative current (AC) power source input module, a direct current (DC) power source supply module, an AC power source output module electrically connected to a load end, a relay, a central control module, a relay driver circuit, a day/night detecting module, a power supply time backward display light set, a power supply time forward display light set, a power supply time backward selection control button and a power supply time forward selection control button. Herein, by pressing the power supply time backward selection control button or the power supply time forward selection control button, one of the power supply time backward display lights or the power supply time forward display lights can be turned on such that the central control module can, based on the sunset time of the previous day as well as the configured power supply backward setting time or power supply forward setting time, postpone or advance the power supply time for the load end in the next day, and then record the sunset time of the next day so as to control the power supply time for the load end in the further next day.

An apparatus for controlling the electrical connection of an electrical load (2), which is arranged at a distance from the apparatus, to a control voltage source (4) which is associated with said electrical load, wherein control is performed by means of two control lines (6, 8) which bridge the physical distance between the apparatus and the load plus the control voltage source and which are connected to a control output (10, 12) of the apparatus, wherein the apparatus has a transducer (14) which detects the value of a state variable (16) of a fluid, and wherein control of the connection is performed depending on the respectively detected value of the state variable (16) exceeding and/or falling below a selectable threshold value, is characterized in that the transducer is formed by a measurement transducer (14) which converts the value of the respectively detected state variable (16) into an electrical signal (18), in that the apparatus has an electronics device (20) for evaluating said electrical signal (18) and for controlling the connection depending on the evaluation, in that the connection is made by means of a controllable electronic switching device (26), which is connected to the control output (10, 12), of the apparatus at least over a first predefinable time period, and in that the power supply device of the apparatus is fed from the voltage of the control voltage source (4) which is applied to the control output (10, 12) of the apparatus via the control lines (6, 8), depending on the switching state of the electronic switching device (26), at least over a further second time period which lies outside the first time period.

In a circuit breaker arrangement, this disclosure describes a method and circuit design enables a current transformer to be used to detect ground faults in circuit breakers (such as a main-tie-main circuit breakers) that have been designed to receive signals from Rogowski coils.

An abnormality detection circuit includes an AC power source coupled to a load via first and second wiring lines, a first relay contact disposed in the middle of the first wiring line, a second relay contact disposed in the middle of the second wiring line, a comparative voltage detection circuit to which a voltage is applied from the AC power source irrespective of whether the first and second relay contacts are open or closed, a first voltage detection circuit to which a voltage is applied from the AC power source when the first relay contact is closed, a second voltage detection circuit to which a voltage is applied from the AC power source when the second relay contact is closed, and an abnormality detector that detects abnormalities of the first relay contact by comparing the voltage applied to the comparative voltage detection circuit with the voltage applied to the first voltage detection circuit and detects abnormalities of the second relay contact by comparing the voltage applied to the comparative voltage detection circuit with the voltage applied to the second voltage detection circuit.

Exemplary embodiments are disclosed that include multi-voltage contactors, controls, and related methods.

A point-on-wave relay device includes a first contact relay and a second contact relay in series with the first contact relay. A first state of the first contact relay in conjunction with a first state of the second contact relay causes a point-on-wave open operation and second state of the first contact relay in conjunction with a second state of the second contact relay causes a point-on-wave close operation.

A switching apparatus is disclosed for switching a current, formed using a phase conductor and a switch arranged in the phase conductor, for the purpose of switching a transmission of current via the phase conductor. In addition, the switching apparatus includes a circuit for deriving a test current from the phase conductor via a ground conductor; a sensing apparatus for detecting the test current and an evaluation apparatus for evaluating the detected test current. A control apparatus is used to control closing of the switch arranged in the phase conductor. The evaluation apparatus is configured to detect a zero crossing for an alternating current and the control apparatus is set up to prompt closing of the switch arranged in the phase conductor in accordance with the time of the zero crossing. An embodiment reduces abrasion or wear on the switch as a result of short-circuit currents during switching-on.

A power-saving circuit for a contactor includes a coil drive circuit, and further includes a rectification and filtering circuit, a PFC circuit, an auxiliary power supply circuit, and a square wave generation circuit. The square wave generation circuit outputs a first square wave signal to the PFC circuit via a first output end according to a set timing sequence, and outputs a second square wave signal and a third square wave signal to the coil drive circuit via a second output end, so as to respectively control duty cycles of a first switch tube in the PFC circuit and a second switch tube in the coil drive circuit. The auxiliary power supply circuit supplies electric energy to the square wave generation circuit during a holding stage of the contactor. The rectification and filtering circuit is used for rectifying an input AC into a pulsating DC, and filtering an input narrow-pulse current into a smooth current to be outputted to the PFC circuit after eliminating higher harmonic components other than a fundamental frequency component of 50 Hz. The PFC circuit receives rectified and filtered electric energy, enables an effective value of the input current to change along with an input voltage, and outputs the input current to the coil drive circuit and the auxiliary power supply circuit. The coil drive circuit is used for controlling the current of a contactor coil. Wherein during a pull-in stage of the contactor, the PFC circuit does not work and the power-saving circuit provides a large current to the contactor coil to pull in; during a transition stage, the PFC circuit starts to work and the power-saving circuit controls the current of the contactor coil to decrease gradually; and during a holding stage of the contactor, the PFC circuit keeps working and the power-saving circuit controls the current of the contactor coil to be kept as a small current required for holding.

In a circuit breaker arrangement, this disclosure describes a method and circuit design enables a current transformer to be used to detect ground faults in circuit breakers (such as a main-tie-main circuit breakers) that have been designed to receive signals from Rogowski coils.