A circuit converts an AC or DC electrical input applied between first and second input leads into a DC output applied to a load via first and second output leads. Four thyristors have their anodes respectively connected to one of the first and second input leads or one of the first and second output leads. Cathodes of two thyristors are connected to the first and second output leads while cathodes of two other thyristors are connected to the first and second input leads. Gates of each thyristor are connected to respective unidirectional switches that open and close at the same time. When closed, the unidirectional switches polarize the gates. Thyristors having a positive voltage on their anodes apply this voltage to the first output lead to power the load. Thyristors having a negative voltage on their cathodes transmit return current from the load to the first or second input lead.

A circuit for controlling current in an inductive load is provided. The circuit includes a driver circuit for driving a load current in the inductive load. The driver circuit includes a switch, which is switched on to increase the load current and a recirculation diode, which re-circulates the load current when the switch is off. The circuit includes a control module that generates a control signal to switch on and off the switch. The control module includes a PWM current controller comprising a negative feedback closed loop implementing at least a proportional control and an integral control. The PWM current controller receives a target current value and an estimated current flowing in the load during a measurement PWM cycle. The PWM current controller generates the control signal for a control input of the switch based on an error between the target current and the estimated current.

A relay device may include an armature that moves between a first position that electrically couples the armature to a first contact and a second position that electrically couples the armature to a second contact. The relay device may also include a relay coil that receives a voltage to magnetize the relay coil, thereby causing the armature to move from the first position to the second position. The relay device also includes an additional coil that couples in series with the relay coil via a switch. The relay device also includes a drive circuit that causes the switch to couple the additional coil to the relay coil in response to receiving a signal indicative of the relay coil energizing.

The electromagnetic coupler uses a coil to induce voltage onto a transistor. By controlling the amount of current that flows through the coil, one is able to can control the strength of the magnetic field emitted by the inductor. And by the controlling the q-point of the transistor, the amount voltage and current induced onto the transistor it can then potentially be used as a switch or an amplifier without any electrical/electronic connection to the internal coil. The use of a transistor enables high speed switching and the potential amplification of communication signals.

Disclosures of the present invention describe a switch device has a controlling and processing unit comprising a first zero point detector, a second zero point detector, an arc detector, and a microcontroller. According to zero crossing point of input voltage signal, zero crossing point of output voltage signal, relay's delay time, and arc-spark-induced signal, the microcontroller is capable of adaptively generating a relay controlling signal to control the relay, such that the relay achieves a short-circuit switching at the zero cross point of output voltage signal for making the output voltage signal be transmitted to at least one load device. Moreover, the microcontroller is also able to control the relay to finish a short-circuit switching at the zero cross point of input voltage signal, so as to stop the output voltage signal from being transmitted to the load device.

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

A control device for an electromagnetic drive of a switchgear includes: a power supply unit for generating a pick-up and a holding DC voltage for the electromagnetic drive of the switchgear, depending on a control signal; and a control unit for generating the control signal, which unit is designed to generate a second control signal for actuating a switch for joining or disconnecting the drive to or from the pick-up or holding DC voltage generated by the power supply unit. The power supply unit includes a switched-mode power supply unit that is designed for an input voltage range matched to an operating voltage range of the switchgear, the input voltage range being approximately 48 volts to approximately 240 volts, approximately 110 volts to approximately 240 volts, or approximately 24 volts to approximately 240 volts. The control unit is designed to generate the second control signal depending on a measuring voltage.

A control circuit and method for a single coil magnetic latching relay is provided in the present disclosure. The circuit includes: a first control circuit (21) and a first single coil magnetic latching relay coil (22). The first control circuit (21) includes: a first transistor (211), a first diode (212), a second diode (213), a first capacitor (214), a second capacitor (215), a first resistor (216) and a second resistor (217) and the first control circuit (21) is configured to control the first single coil magnetic latching relay coil (22) to enter a preset state and/or maintain the preset state.

The present invention relates to a technology that monitors a normal operation state through whether the flow of minute current is maintained in real time when a latch relay is turned on and allows the latch relay to be forcibly turned off through current prestored in a supercapacitor when an off operation of the latch relay is not normally performed.

The electromagnetic relay includes a fixed terminal, a fixed contact connected to the fixed terminal, a movable contact piece moving in an opening direction and a closing direction with respect to the fixed terminal, a movable contact connected to the movable contact piece and being arranged to face the fixed contact, a coil generating an electromagnetic force to move the movable contact piece, and a drive circuit controlling a current to the coil. The drive circuit increases the current at a first increase rate in a first period that includes a period from a start time when the current starts to flow in the coil to before a contact time point at which the movable contact contacts the fixed contact. The drive circuit increases the current at a second increase rate larger than the first increase rate in the second period that includes a period after the contact time point.