Single vs. Dual Coil Latching Relays: Understanding Their Differences and Applications

Update:18-10-2023

Latching relays are essential components in various electrical and electronic systems, designed to maintain a specific switch position without requiring a continuous supply of power. They are employed in applications where energy efficiency, space savings, and reliability are crucial. Single and dual coil latching relays are two common variations of these devices, each with its unique characteristics and applications. In this article, we will delve into the differences between single and dual coil latching relays, how they work, and where they find use in the world of electronics and control systems.

Latching Relays: The Basics

Latching relays, also known as bistable relays, are a type of relay that can maintain their switch position with a short pulse of energy. Unlike standard relays that require a continuous coil current to remain activated, latching relays use a clever mechanical or magnetic mechanism to "latch" in either the open or closed position after an initial pulse.

Single Coil Latching Relays

Single coil latching relays, as the name suggests, utilize a single coil to both set (energize) and reset (de-energize) the relay. When a short electrical pulse is applied in one direction, the relay switches to one state (for example, closed), and when a pulse of the opposite polarity is applied, it switches to the other state (open). The single coil design is simple and space-efficient.

Dual Coil Latching Relays

Dual coil latching relays, on the other hand, use two separate coils, each responsible for setting or resetting the relay. When an electrical pulse is applied to one coil, it sets the relay to one position, and when a pulse is applied to the other coil, it resets the relay to the opposite position. Dual coil latching relays are known for their higher sensitivity and ability to operate at lower voltages compared to their single coil counterparts.