Latching – Bi-Stable High-Voltage Relays

Latching relays provide a unique feature that can be used in any basic relay form, SPST, SPDT, or DPDT. Most relays and contactors are considered “fail-safe.” Fail-safe relays require coil power applied continuously to make sure the relay is switched. Once coil power is removed the moveable contact in a fail-safe relay returns to its default position.

Latching relays require a momentary coil pulse to change the position of the moveable contact. Continuous coil power is not required to keep the relay in a particular switched state. When the application circuit needs to switch a latching relay, it sends a pulse to the coil to change the moveable contact position.

Click here for an Industrial High-Voltage Relay Application and Design Guide.