Hi guys,
let me begin from the beginning. Sometimes it can be very cold in winter here in Northern Europe, sometimes it can be really cold, up to -25C / -13 F and it would be very nice to have a car warmed up a bit to the moment you get in. So I decided to make my next project a remote starter for my beloved '88 240 B230F, triggered by a cellular phone call.
It would take too long to explain how do I manage filtering incoming calls and making all the communicational stuff work, but the result is going to be a wire going from 0 to +12V after the call is made. It's great for powering ignition, but is veery problematic for starter.
In a normal world, my Volvo cranks from 0.25 to about 4 seconds until engine starts running by itself and I return the key from Start position back to On. My Great Problem is to teach stupid electronics to feel that engine is running on it's own already and starter can be disengaged.
So I ask you for help to find some changing condition (voltage, current, resistance) somewhere that would say that engine doesn't need starter anymore and can continue running. One possibility could be counting RPMs (tacho), but it's too expensive to use electronic components that open/close contacts upon tach pulse limit. I've seen in the internet some aftermarket no-tach remote starters, but have no idea, how they perform that task. Some cheap ones have fixed crank time (like 3sec), but I don't want my starter get burned because of being daily engaged for some time after engine is already running.
Thanks for reading such a long post.
IF
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