Analysis of Operating Principle of Relay Drive Circuit

Analysis of working principle of relay drive circuit:

There is a set of coils inside the relay. Before the relay is powered off, the direction of the current flowing through the relay coil L1 is from top to bottom. After the power is turned off, the coil generates a counter electromotive force to hinder this current change, that is, a flow from top to bottom occurs. Current.

Relay drive circuit analysis details explain:

The details of the analysis of the above-mentioned diode simple DC voltage regulator circuit are described below.

(1) In the circuit analysis, the unidirectional conductivity of the diode can be used to know that the diode is in a conducting state, but it does not explain what specific effects these several diodes have on the circuit after conduction. Therefore, only one-way conductive characteristics are not used. Can correctly analyze the working principle of the circuit.

(2) Among the many characteristics of diodes, only the characteristics of the voltage drop of the tube after conduction is basically the same can explain the function of this circuit most reasonably. Therefore, based on this point, this circuit can be determined to stabilize the direct current at point A in the circuit. Operating Voltage.

(3) When there are many components in the circuit, it is necessary to find out the main components that realize the circuit function, and then carry out analysis around it. The main features of the component are used in the analysis to provide a reasonable explanation.

The internal circuit of the relay drive circuit has a coil structure, so it will generate a large voltage back electromotive force when it is powered off, and will break down the driving triode of the relay. To this end, a diode protection circuit is provided in the relay drive circuit to protect the relay drive. tube.