Features:1. Turn on the power relay to pull in and off at a fixed cycle of 1-10s. Specifically: after the relay is supplied with 12v power, the relay will not immediately sink. The state of the relay output is: normally open and common conduction, normally closed and public disconnected; wait until the delay is 1-10s (can be adjusted), the relay Released, at this time, the state of the relay output is: normally open and common open, normally closed and common conduction; as long as the module is continuously powered, this state will remain closed and released at a fixed cycle of 1-10s.2. Delay time is adjustable, (0~10 seconds).3. Increase the potentiometer to increase the delay time.4. Increase the capacitance C1 to increase the delay time.5. With input power indicator.6. With relay pull-in indicator.7. Can control AC 220V/10A equipment. (Maximum control device 2000W).8. With relay freewheeling protection.9. Delay time formula: T = 1.1RC. For example: Capacitance 100uf resistance 100K T = 1.1 * 100000 * 0.0001 = 11 seconds.Specification:Main chip: NE555Working voltage: DC 5 voltsSize: approx. 6 * 1.7cm / 2.4 * 0.7inWeight: approx. 34gPackage list:2 * Relay Module