Motion sensor for security light

[garv]

hi to all,
i am working on motion sensor project and in need of help now.....here i am attaching the circuit, plz lemme knw the connection of coil and diode in circuit coz i could not understand wat is it and why it is done for??....plz help me out and also tel me whether it is possible to make this circuit work with dc supply if yes than plz help me with simplified circuit to work with dc supply...thank u...

 

[kapilp]

@ garv ... the 'coil' in your circuit is actually a part of the relay (look above the coil for specs) alongwith the 2 switches. The diode is used as a 'freewheel diode'. The relay 'turns on' the triac and the CFL ... study the individual parts .... will help a lot as this is a very simple circuit.
This circuit is made to run on your domestic supply so that u can use it at your home (the 'core' is dc based though)
For the DC model, replace the input and rectifier section with a dc supply, and you will need a comparator acting as the switch ... as i said earlier ... refer datasheets