Principle of Magnetic Latching Relay

Principle Of magnetic latching relay (Detailed Explanation of Magnetic Latching Relay Drive Circuit Diagram and Wiring Method)

There are many classifications of relays, but most of the relays have the same principle. Compared with ordinary electromagnetic relays, magnetic latching relays have the advantage of low power consumption. When the coil is energized, some electrical energy is consumed. After the trigger pulse disappears, the internal permanent magnet keeps the relay in its original state. What Meishuo is going to talk about below is the principle of magnetic latching relay and the driving circuit diagram and wiring method.

Principle of Magnetic Latching Relay

The normally closed or normally open state of the magnetic latching relay is completely dependent on the action of permanent magnets, and the switching state of the relay is triggered by a pulse of a certain width.

Magnetic latching relay ~ generally composed of the iron core, coil, armature, contact reed, etc. As long as a certain voltage is applied to both ends of the coil, a certain current will flow in the coil, which will produce electromagnetic effects. The armature will overcome the pulling force of the return spring and attract the iron core under the working principle and the characteristic electromagnetic force attraction. Thereby driving the movable contact of the armature and the static contact (normally open contact) to attract and close.

When the coil is de-energized, the electromagnetic attraction will also disappear, and the armature will return to the working principle under the reaction force of the spring, characteristic of the original position, and make the moving contact and the original static contact (normally closed contact) attract and close. This pulls in and releases, so as to achieve the purpose of conducting and cutting off in the circuit. For the "normally open and normally closed" contacts of a magnetic latching relay, it can be distinguished as follows: the static contact that is in the off state when the relay coil is not energized is called "normally open contact"; the static contact that is in the on the state The points are called "normally closed contacts".

When the input quantity (such as voltage, current, temperature, etc.) reaches the specified value, the electrical appliance that makes the output circuit controlled by the working principle and characteristic turns on or off. It can be divided into electrical quantity (such as current, voltage, frequency, power, etc.) relays and non-electric quantity (such as temperature, pressure, speed, etc.) magnetic latching relays.

The magnetic latching relay drive circuit shown in the figure above is driven by a special device BL8023, which has a simple circuit and low static power consumption. The recommended operating voltage of BL8023 in the circuit is 5 ~ 25V, the static power consumption is in the μA level, and the drive current can reach 400mA.