This delay relay module is widely used in robot, automobile lamp, intellectual product development, PLC and electronic development etc.
The delay time can be adjusted through potentiometer, and the default value is 0.1s to 25 seconds. You can greatly extend the timespan by replacing a large capacitor or potentiometer. Protection against power reversal protection diode, better protection module. It can be accessed by a large current load (250V ac 10A or 30V dc 10A).

Specification:
Operating Voltage: DC 12V
Load Capacity: AC 250V 10A; DC 30V 10A
Delay Time: T(S)=1.1*R(Ω)*C(f); e.g. if capacitor is 47uf, resistor is 500KΩ, T=1.1*0.000047*500000=25.85sec.
Size: 52*16mm/2.04*0.62"

Working Principle:
1. Power on the module (12V or 5V) and relay is energized immediately. N.O. terminal is connected to COM terminal.
2. Relay is dis-energized after 0 to 25 seconds. N.C. terminal is connected to COM terminal.
3. Relay keeps dis-energized until there is an external trigger signal.
4. If there is always trigger signal, relay will keep energized until trigger signal disappears, then dis-energized after 0 to 25 seconds. Now N.C. terminal is connected to COM terminal.

Package Includes:
1 x Timer Relay Module