The role and operating characteristics of the relay


The function and working characteristics of the relay. […]

The function and working characteristics of the relay. The relay is an electronic control device. It has a control system (also called an input loop) and a controlled system (also called an output loop). It is usually used in automatic control circuits. A kind of "automatic switch" that uses a small current to control a larger current. Therefore, it plays the role of automatic adjustment, safety protection, and conversion circuit in the circuit.

1. Rated working voltage

The voltage required by the coil when the relay is working normally. Depending on the model of the relay, it can be AC ​​voltage or DC voltage.

2. DC resistance
The DC resistance of the coil in the relay can be tested with a multimeter.

3. Pull in current
The relay can generate the minimum current for the 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 the times of the rated working voltage, otherwise it will generate a larger current and burn the coil.

4. Release current
The relay generates the maximum current for the release action. When the current in the pull-in state of the relay decreases to a certain extent, the relay will return to the unpowered release state. The current at this time is much smaller than the pull-in current.

5. Contact switch voltage and current
The voltage and current that the relay allows to load 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.

The main function of the contactor is to connect or disconnect the main circuit. The so-called main circuit refers to whether a circuit works or not is marked by whether the circuit is connected. The main circuit concept corresponds to the control circuit. Generally, the current through the main circuit is larger than that of the control circuit.