nqtraderman
New Member
I have a 50's classic car and I'd like to fit an immobiliser to the ignition circuit (12v) but I need help with its design.
I'm thinking of a circuit that would control a 12v 10amp relay which interupts the 12v supply to the ignition.
As well as flashing a LED at 5 secs intervals when activated I'd like it to have an inbuilt adjustable timer that allowed the car to start but then after the pre set time, eg 30 secs, it operated the relay and open circuits the ignition wire. The timer would stay in this state for 30 secs before restoring the connection to the relay.
My thoughts are this :
1. the flashing LED makes it look like a standard car alarm / immobiliser
2. the timer function gives the impression that the car is OK allowing it to start but then develops problems and after a few cut-outs the thief will give up and move on as this is an open top roadster with no door locks so it is impossible to stop anyone getting into the car.
3. It also has a mechanical fuel pump so its not possible to cut that off electrically either.
If it could be operated by remote then that would be even better but a simple hidden on/off switch would be OK.
Although I used to do electronics many years ago, I'm totally out of it nowadays from a design perspective but I would be able to construct it from a diagram.
So if anyone could design a circuit for me along these lines that would be really helpful.
many thanks
PS
I found this circuit of a flashing LED. Could this be adapted ?
I'm thinking of a circuit that would control a 12v 10amp relay which interupts the 12v supply to the ignition.
As well as flashing a LED at 5 secs intervals when activated I'd like it to have an inbuilt adjustable timer that allowed the car to start but then after the pre set time, eg 30 secs, it operated the relay and open circuits the ignition wire. The timer would stay in this state for 30 secs before restoring the connection to the relay.
My thoughts are this :
1. the flashing LED makes it look like a standard car alarm / immobiliser
2. the timer function gives the impression that the car is OK allowing it to start but then develops problems and after a few cut-outs the thief will give up and move on as this is an open top roadster with no door locks so it is impossible to stop anyone getting into the car.
3. It also has a mechanical fuel pump so its not possible to cut that off electrically either.
If it could be operated by remote then that would be even better but a simple hidden on/off switch would be OK.
Although I used to do electronics many years ago, I'm totally out of it nowadays from a design perspective but I would be able to construct it from a diagram.
So if anyone could design a circuit for me along these lines that would be really helpful.
many thanks
PS
I found this circuit of a flashing LED. Could this be adapted ?