Use of LDR sensor with concept of voltage divider in headlights of vehicle.

[Ishwanku]

I want to use LDR as sensor in headlights of the car which on falling of light on it in high beam take the high beam to low beam and as the falling of light on it stopped it automatically get back to high beam.and if the light is on low beam nothing occurs.How will it be possible to perform this only with high beam please reply asap?

 

[chuckey]

Some where in the car there will be a relay that changes the hi/lo beam when the switch is pressed. Take the wire off the hi beam contact and feed it into another relay, which feeds the hi beam supply out to the original hi beam wiring. When this second relay is energised the live hi beam wire is now taken to the lo beam wiring. This can be tested before your install your auto dipper.
Frank

 

[Ishwanku]

Bt how it will be connected with LDR and how will LDr have to be used so that as light strikes LDR it automatically gets to low beam and then to hi beam

 

[chuckey]

you need a transistor to drive the relay. So to make the relay work you have to inject current into the transistors base, so wire up the LDR with some extra resistors to do this. A diode needs to be put across the relay coil to protect the driving transistor.
Frank

 

[Ishwanku]

it all about making it autosensor detection of light