Feature: 12V trigger delay normally open relaymodule, 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 largercapacitance or potentiometer. Power supply terminal has anti-reversediode for protection. Trigger signal can be high level or lowlevel signals, suitable for industrial control, the module can be triggeredrepeatedly. 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()*C(f); e.g.if capacitor is 47uf, resistor is 500K, 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 relayis energized immediately. N.O. terminal is connected to COM terminal. 2. Relay is dis-energized after 0 to 25seconds. N.C. terminal is connected to COM terminal. 3. Relay keeps dis-energized until there isan external trigger signal. 4. If there is always trigger signal, relaywill keep energized until trigger signal disappears, then dis-energized after 0to 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..