Magnetic latching relays are used to facilitate the remote disconnection and reconnection of power to the consumer premises. A latching relay is a two-position electrically actuated switch. Turning the relay on and off simply requires a momentary application of a trigger pulse current to the relay coil. And we’ll start the production process from the coil winding.

Coil Winding

According to the structure, we have two type of coils, single coil and double coil. After final assembly, we can find there’s two pins or lead wires for single coil latching relay, and three for double coil latching relay.The typical coil voltage is 6V, 9V, 12V, 24V, 48V and so on. After coil winding, there’s usually a process of lead wire assembly.

Coil Latching Assembly

The coil cannot be fixed properly inside the plastic housing without a coil latching. So, we’ll assemble it by automatic vibration feeder.

Coil Riveting

After the assembly of coil latching, we’ll rivet the coil by jigs and fixtures.

Coil Assembly

Then, we’ll put the coil inside the plastic housing and fix it. Usually, the structure of plastic case of single phase latching relay is simple. Sometimes, the EBW manganin shunt is a critical part which should be assembled in the relay case as well.

Cable Riveting

Nearly all latching relays are brazed by accessories, such as shunt, multi strand wires, or copper lugs. So, there’s usually a production process for the accessories.

Spot Welding

After the preparation of accessories, we’ll weld them to the relay base by spot welding machine. For some three phase latching relay, we’ll weld 6 multi strand wires to the relay base. Many customers need latching relays integrated with current transformers, which should be mounted in the copper lugs.

Retain Force Test

The retain force is a very important parameters for a latching relay. Therefore, we’ll test it by force meter and make sure the retain force is within the upper and lower limit.


Then, we’ll inspected other electronic parameters of a latching relay. Any defect ones will be removed from production lines.

Packing & Shipment

After assembly and inspection, the latching relays will be put in small paper boxes properly. Considering shipment, we’ll put these boxes inside cartons and wooden cases to protect them from vibration or damaging.

Latching Relay: Production Process