FEATURE1. Timing Adjustable relay switches from mili-seconds to hours.
2. Time setting by varies RC value of the 555 Timer.
3. Built-in low dropout voltage regulator LM1086-5 IC.
4. Wide range of DC Power supply: 6-30V
5. Max rating of Relay: 120VAC 1A
Applications: Delay protection for speaker, power supply, etc.
1. Soldering the components according to the schematic and BOM.
2. The timing constant (delay time) is set by the RC time constant, that are the resistors R1, R2, R3, R4, R5, and R6, and C4. The higher the time constant, the longer delay time will be resulted. The relationship between the delay time ranged from micro seconds to few seconds is shown in the below figure. By properly setting the RC value, you can control the delay time of the relay switch.
3. Apply the power supply, you will hear the 'click' sound or LED light up when the relay are switched on after the predefined delay timing.