From the perspective of structure and working principle, the magnetic latching relay is an automatic switch, and it is also a new type of relay developed in recent years. The magnetic latching relay has the function of automatically turning on and off the circuit. Different from electromagnetic relays, the normally closed and normally open states of magnetic latching relays are all dependent on the action of permanent magnets, and the switching of their switching states is accomplished by triggering a pulsed electrical signal of a certain width.
When the input quantity (such as current, voltage, temperature, etc.) reaches a specified value, the controlled output circuit turns on or off the electrical appliance. It can be divided into two categories: electrical quantity (such as frequency, current, power, voltage, etc.) relay and non-electrical quantity (such as temperature, speed, pressure, etc.) relay. It has the advantages of stable work, small size, long life, and fast action. Therefore, it is widely used in automation, remote control, measurement, power protection, sports, and communication devices.
Magnetic Latching Relay Internal Structure
It is divided into upper and lower layers, the upper layer is the electromagnetic system, and the lower layer is the contact system. The electromagnetic system adopts a flat direct-acting magnetic retention magnetic circuit system, which includes a mounting plate. The magnet, magnet, coil, iron core, and armature are arranged in the center of the mounting plate. There are installed coils on both sides of the magnet, and a U-shaped iron core is arranged above the coil, and the armature is located between the iron cores to form a ring structure, and then the magnetic field is used to control the work. Both ends of the mounting plate are located next to the U-shaped bottom of the iron core, and a pure iron plate is also installed to prevent the interference of external magnetic fields.
The working principle of the magnetic latching relay
Generally, the open and closed states of the magnetic latching relay contacts are maintained by the magnetic force generated by the permanent magnet. When the contacts of the relay need to be opened or closed, the coil only needs to be excited by the positive (reverse) DC pulse voltage, and the relay will instantly complete the switching of the opening and closing states. Usually, when the contact is in the holding state, the coil does not need to continue to be energized, and the state of the relay can be maintained by the magnetic force of the permanent magnet.
The operation process of the magnetic latching relay
When the contacts of the relay need to be set, it is only necessary to use the positive DC pulse voltage to excite the coil J2, and the magnetic poles generated by the excitation of the coil J2 interact with the magnetic poles of the permanent magnet, the same polarity repels each other, and the opposite polarity attracts each other, so that the relay The reset to set state transition is completed in an instant. The process of the magnetic latching relay changing from the set state to the reset state is the same.
Advantages of Magnetic Latching Relays
1, safe and reliable, long life
2. Only need pulse excitation, can work with single and double coils
3. Low power consumption and strong load capacity
4. Small size, PCB type installation
From the perspective of environmental protection, the disadvantage of magnetic latching relays is that compared with electromagnetic relays, the only disadvantage is that they consume more materials. In the long run, its environmental performance is better than that of ordinary electromagnetic relays. The seismic performance of ordinary relays is not much different from that of magnetic latching relays.