A Latching Relay is a unique type of relay that stands out from regular relays due to its ability to “latch” or hold its state after being activated. Unlike conventional relays that require continuous power to maintain their position, a latching relay only requires power momentarily to switch between two states and will stay in the last activated state until a different signal is applied. This key feature makes the latching relay highly suitable for energy-efficient applications and systems that require memory or the ability to hold a state without constant power.
How Latching Relays Work At the core of the latching relay’s function is its dual-state mechanism, often referred to as a “bistable” or “dual-stable” operation. A latching relay has two stable positions： one in which the switch is closed (ON), and the other in which it is open (OFF). When a signal is applied, the relay switches to the opposite state and remains there without needing continuous power. To switch the relay back to its original state, a different signal is required. This switching mechanism is typically achieved through electromagnetic forces. A magnetic latch system is used to keep the relay in the chosen state. In a typical setup, the relay uses two coils or electromagnets, each corresponding to one of the stable states. Applying a current to one coil will switch the relay to one state, while applying current to the other will switch it back. Once the relay has moved to its new state, no additional power is required to maintain that position.