Feature: 12V trigger delay normally open relay module, repeatedly triggering effective. Delay time can be adjusted by potentiometer(clockwise to reduce, anticlockwise to increase), default 0-25 seconds, if you need more time, simply replace a larger capacitance or potentiometer. Power supply terminal has anti-reverse diode for protection. Trigger signal can be high level or low level signals, suitable for industrial control, the module can be triggered repeatedly. It can be used in robotics, car lamp delay, intelligent product development, automation equipment, PLC development, intelligent home, burglar alarm delay, and development of electronic. 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:Approx. 67 x 16mm/2.64 x 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 Note: Please note that the new type and old type of this product will be sent randomly, and make sure you will not mind before ordering. .