Help! Security Light & Switch with PIR Sensor

Thread Starter


Joined Aug 12, 2013
Im currently working on this project
and using SB00622A-2 PIR Sensor instead of the PIR sensor given in the circuit because the PIR sensor available in our country is just SB00622A-2 and using LMR2-12D relay. Its not working to me and i dont know where to connect the load pins in the SB00622A-2 it is neccesary to connect it?. The led is not turning on and when i remove the no. 3 pin of the PIR on the ground the led is turning on. I dont know whats the problem . Im Using T1 and T2 is BC547B.
D2 is 1n4002.



Joined Jun 5, 2009
I think you could use a 12vdc supply without R1,D1 or C1.

The output current on the SB00622A-2 is 100mA so I think you could use that relay straight to the output + and - ... not forgetting the diode.

Then use a 500ohm current limiting resistor for the white LED assuming its 3.2v 20mA but still feed the spare contact with 12vdc.

I may be wrong so hopefully somebody more experienced will check this :)

Thread Starter


Joined Aug 12, 2013
i followed whats in the thumbnail and use a 12dc 1000ma source because thats the only 12v source i have,
i saw a little white smoke on the pir and i suddenly disconnect the source, thank god the pir sensor is still working.


Joined Aug 7, 2008
Whoops & sorry; relay & LED got reversed when connected to PIR, another senior moment; crowding 90, and it's beginning to show.