Circuit Project Electronic

The intermittent wiper circuit shown above causes the auto’s windshield wipers to wipe
once every several seconds instead of constantly wiping. The circuit may be added to
older cars to provide the intermittent function or it may be used to replace broken wiper
circuits in modern cars.
Read more original source:
http://www.techlib.com/files/wiperkik.pdf

This circuit switch slowly on and off the internal lights in a car. The delaying time can be adjusted changing the values of the 10k, 4M7 resistors and capacitor.
The BUZ74 can handle voltages of 500V, but you can use any power Mosfet transistor that can handle more than 50V.
Related Links
More about automotive
More circuit about [...]

It works on the sonar principle, sending an ultrasound burst and listening for first echo. The burst generated by the oscillator built around U4D (you must set the frequency using TR2 to have 40 kHz or the maximum sensitivity), U4E buffers the output and U4F boost the signal doubling the voltage span across the TX [...]