Best Motion Sensor Light Switch Circuit Diagram

Use 5v To 12V DC to operate this circuit But Make sure that Sensor is Required only 5v dc so use a 5v voltage regulator LM7805.

• The Vcc pin of Sensor Is Connected with 5v Dc, Ground Pin Is connected With Negative DC Supply And Output Of Sensor Is Connected With  BASE Of NPN Transistor (Here BC547 Is used).

• Use a Relay According to Input Voltage For connecting any Light

• If There is No Any Movement Or Motion Occur, Then Sensor Give LOW output And Transistor Is Turned Off Because There is No Any Input Of BASE terminal. When any Motion/Movement Occur, Then It Detects by Sensor And Its Output Is High. Because The Output Is HIGH, The Transistor Gets High input at the BASE and it Turns ON and Relay is activated. As Relay is activated the Light connected with this will Switched ON.

• The Output Of Sensor Is Automatic LOW After a Time Duration Set By User. So the Alarm Or Light Which Is connected is Automatically Switched Of After Some Time.

• If You Want To Use Only Alarm, Then No need to Relay And Alarm is Directly Connected With Collector Of transistor And Power Supply. But That time uses only 5v directly, no need to use any regulator.

• This Circuit of Security Alarm Using the PIR sensor is Also Works At Night in Dark. So This is very useful for Security   Alarm And Security Light Uses. 

• PIR Sensor has 2 preset, one is Adjustment of Sensitivity of its and second is The Adjustment Of Time Delay Which Remain High at Output For A Duration.