12V halogen lamp soft starter

[fjpompeo]

I need a 12V halogen lamp PWM soft starter for my car. Every time a turn on the motor after a 5s delay the low light bean turns on using a PWM soft start method so the life of the bulbs will be very long. I think that the only way to monitor the engine is using an alternator signal picked-up in the terminal W, see a test here, https://www.youtube.com/watch?v=O61SbhHgZBo, a zener voltage limiter in the PIC12F629 input will do the job.

Regards,

Fernando

 

[BradtheRad]

A simple way to make PWM with growing duty cycle, is to apply a rising voltage to the CTL pin of a 555 pulse generator.

The capacitor at left charges gradually, creating the rising voltage over a period of several seconds.



Is this for your headlamp? Homemade circuitry controlling your headlamp is risky. A malfunction could disable your headlamp just when you need it.

And it's a good idea to install a relay, closing it at the end of your soft start, so the lamp runs on 100 pct duty cycle.