The relay time delay and power supply is connected.Specific as follows: for 12 v power supply to the relay, relay not immediately and absorption, relay the output status to: normally open and public disconnect, normally closed and public conduction;Wait for delay 1-10 s (adjustable), relay and absorption, at this point, the relay outputs status to: normally open and public conduction, normally closed and public disconnected;As long as the module power continuously, this state will remain.The delay time is adjustable, (0 ~ 10 seconds)IKncreasing the potentiometer can increase the delay timethe capacitor C1 can increase delay timewith input power lightA relay and indicator lightsControlled ac 220 v / 10 a device.(maximum control equipment 2000 w)Stream with relay protection.The delay time formula: T = 1.1 RC.For example: 100 uf capacitance resistance 100 k T = 1.1 * 100000 * 0.0001 = 11 secondsThe on-board equipment on the time delay, prevent excessive current when the car lighter burned on-board equipment.Need to have order to start the occasion, to prevent multiple devices at the same time starting current is too large burning appliances.The main chip: NE555Working voltage: DC12VColour:red+green+blueMaterial:PC, MetalSize: 6.8 x 2.1cmPackage Contents:5 x NE555 Delay Relay Shield TimerOnly the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.