A switch device includes: a receiving conversion component, configured to receive a wireless signal and convert the received wireless signal into a power supply signal; a first power component, connected to the receiving conversion component, and configured to store electrical energy based on the power supply signal; a control component, connected to the first power component, and configured to enter a working state based on the electrical energy supplied by the first power component, and generate a control signal in the working state; and a first switch component, connected to the control component, and configured to change to be in an on or off state according to the control signal, wherein the first switch component is arranged on a power supply loop of a controlled device to which a second power component is configured to supply electrical energy in the on state.

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.

Systems, devices, and methods including: a relay, the relay comprising: at least one contact; a reflector attached to at least one contact; a sensor, the sensor comprising: an emitter configured to emit a pulse; a detector configured to receive a portion of the emitted pulse; where the reflector may be configured to reflect at least a portion of the emitted pulse to be received by the detector when the at least one contact may be in at least one of: an open position and a closed position

A system includes a current transformer including: a primary coil, and a secondary coil including at least two taps; a tap selection circuit; a current measurement apparatus configured to produce an indication of an amount of current flowing in the secondary coil; a power supply electrically connected to a first one of the taps, the power supply configured to receive electrical power from the first one of the taps; and a controller coupled to the power supply and the current measurement apparatus, the controller configured to receive electrical power from the power supply and to control the tap selection circuit based on the indication of an amount of current in the secondary coil.

A system includes a current transformer including: a primary coil, and a secondary coil including at least two taps; a tap selection circuit; a current measurement apparatus configured to produce an indication of an amount of current flowing in the secondary coil; a power supply electrically connected to a first one of the taps, the power supply configured to receive electrical power from the first one of the taps; and a controller coupled to the power supply and the current measurement apparatus, the controller configured to receive electrical power from the power supply and to control the tap selection circuit based on the indication of an amount of current in the secondary coil.

A control unit includes: an input portion that receives the positional information of a vehicle; a calculation unit that generates a control signal for controlling an electromagnetic relay; and an output portion that outputs the control signal to the electromagnetic relay. The calculation unit determines whether a location region of the electromagnetic relay is a relay-freeze region, the location region being identified by the positional information of the vehicle, and, when the location region of the electromagnetic relay is a relay-freeze region, performs a freeze inhibiting process for preventing the electromagnetic relay from being frozen or defrosting the electromagnetic relay by opening and closing the electromagnetic relay and causing the electromagnetic relay to vibrate.

A boat having an electric motor coupled with an electrical store is disclosed. The electrical store includes a storage element, and positive and negative poles in current-conducting connection with the storage element. An isolating circuit element is operatively connected to a user activatable emergency stop switch. The isolating circuit element is configured to, upon activation of the emergency stop switch, isolate the current-conducting connection between the storage element and at least one of the poles.

A boat having an electric motor coupled with an electrical store is disclosed. The electrical store includes a storage element, and positive and negative poles in current-conducting connection with the storage element. An isolating circuit element is operatively connected to a user activatable emergency stop switch. The isolating circuit element is configured to, upon activation of the emergency stop switch, isolate the current-conducting connection between the storage element and at least one of the poles.

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.

An object is to provide a DC power supply connector that can suppress occurrence of an arc discharge at DC power off with a small-scale configuration without reducing power efficiency during DC power supply and can reduce heat generation.

The connector includes, on at least any of a positive-electrode-side electrode side and a negative-electrode-side electrode side, a movable contact piece (20c) that touches a first contact (25) in a state where a terminal (11) on a power receiving side has been inserted and to touch a second contact (24) in a state where the terminal has not been inserted, and a current limiting circuit (30) including a switching element (T1). The current limiting circuit (30) does not flow a current to the switching element (T1) in the case where the movable contact piece (20c) is touching the first contact (25), and flows a current to the terminal (11) through the movable contact piece (20c) until the movable contact piece (20c) is linked to the second contact (24) after separation from the first contact (25), and gradually decreases the flowing current.