Automotive

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.
Read More Source:
http://www.next.gr/view-link4.php?id=4355

This was one of my first designs: it is an ultrasonic parking sonar.
Based on an ultrasonic amplifier from an article seen on a 1982 magazine, it was once installed on the rear bumper of my Volvo Station Wagon. It served very well for many years. Connecting it to the reverse gear lights, it switches on [...]