Relay is an electrical control device. It is an electrical appliance that causes the controlled quantity to undergo a predetermined step change in the electrical output circuit when the input quantity (excitation quantity) changes to meet the specified requirements. It has an interactive relationship between the control system (also called the input loop) and the controlled system (also called the output loop). Usually used in automated control circuits, it is actually an "automatic switch" that uses a small current to control the operation of a large current. Therefore, it plays the role of automatic adjustment, safety protection, and conversion circuit in the circuit.

Relay is an automatic switching element with isolation function. It is widely used in remote control, telemetry, communication, automatic control, mechatronics and power electronic equipment. It is one of the most important control elements.

 

 

Relays generally have an induction mechanism (input part) that can reflect certain input variables (such as current, voltage, power, impedance, frequency, temperature, pressure, speed, light, etc.); The actuator (output part) of "off" control; between the input part and the output part of the relay, there is also an intermediate mechanism (drive part) for coupling and isolating the input, functional processing and driving the output part.

Main product technical parameters of relay

Rated working voltage: refers to the voltage required by the coil when the relay is working normally. Depending on the type of relay, it can be AC ​​voltage or DC voltage.

DC resistance: refers to the DC resistance of the coil in the relay, which can be measured with a multimeter.

 

Pull-in current: refers to the minimum current that the relay can produce a pull-in action. In normal use, the given current must be slightly larger than the pull-in current, so that the relay can work stably. As for the working voltage applied to the coil, generally do not exceed 1.5 times the rated working voltage, otherwise it will produce a larger current and burn the coil.

 

Release current: Refers to the maximum current that the relay generates to release the action. When the current in the pull-in state of the relay is reduced to a certain level, the relay will return to the unpowered release state, and the current at this time is much smaller than the pull-in current.

 

Contact switching voltage and current: refers to the voltage and current that the relay allows to load. It determines the magnitude of the voltage and current that the relay can control, and this value cannot be exceeded during use, otherwise it is easy to damage the contacts of the relay.