A relay impulse, also known as an impulse relay or bistable relay, is a type of relay that changes its contact position with each pulse it receives.
Understanding Impulse Relays
Unlike traditional relays that require continuous power to maintain a specific state, impulse relays "latch" into their last position. This means they retain their state even after the pulse signal is removed, making them energy-efficient for applications requiring state memory.
How Impulse Relays Work
Many impulse relays combine a magnetic latching relay with a solid-state steering circuit. The steering circuit analyzes the relay's current position upon receiving power. It then energizes the appropriate coil to switch the contacts to the opposite state. This switching happens with each incoming pulse.
Key Features
- Latching Action: Retains its state (on or off) after the control signal is removed.
- Pulsed Operation: Switches state with each incoming pulse signal.
- Energy Efficiency: Consumes power only during switching.
- State Memory: Remembers the last state.
Applications
Impulse relays are commonly used in:
- Lighting Control: Switching lights on and off from multiple locations using momentary switches.
- Remote Control Systems: Controlling devices remotely with pulse signals.
- Building Automation: Managing various building systems such as HVAC and security.
- Industrial Automation: Controlling machines and processes.
- Staircase Lighting: Controlling lights on staircases with momentary push buttons.
Example Scenario
Imagine a hallway light controlled by two switches at either end. Using an impulse relay, pressing either switch (a momentary switch providing a pulse) will toggle the light on or off, regardless of the state of the other switch. This eliminates the need for complex wiring and maintains the desired state even if a power outage occurs.
