What Is A Time Delay Relay?

The time delay relay is a time control instrument used to establish or interrupt a connection after or before a preset time. Its working principle is that after receiving the input signal, it does not change its output state immediately, but waits for a preset time interval before changing the output. Time relays are widely used in various industrial automation and control applications to achieve the following functions:

1. Delayed operation: In some control logic, it is necessary to delay a certain operation after receiving a trigger signal.
2. Sequential control: In a system where multiple operations need to be performed in a specific order, a time relay can ensure the time interval between operations.
3. Pulse delay: In a pulse control system, a time relay can be used to delay the output of a pulse signal.
4. Safety protection: In some safety-related applications, a time relay can be used to delay the action of a circuit breaker or contactor.
5. Fault detection: A time relay can be used to detect whether a device responds within a specified time. If not, it may indicate a fault.

Time Delay Relay Types

1. On-delay time relay: The on-delay relay will not work immediately after being energized, but will wait for the preset time to elapse before starting to operate.This type of relay is widely used to sequentially connect the power supply of different components in the control system.
2. Off-delay time relay: Off-delay time relay is just a reverse to the on-delay time relay, after the power is removed, it will work for a short time as scheduled. This relay can be found in gas water heater fan control, projector temperature control, etc.
3. Flicker timer relay: The flicker timer relay is a on/off circular time relay, after presenting the relay, it will work on and off circularly.
4. Interval timer relay: This relay will work for a setting time after power on, then turn off, Once power it on again, it will work the same again.
5. One shot timer relay: This relay will turn on or off a load for a time after detecting an external trigger signal, we can usually find it in lighting control with human body sensors, motion detectors etc.