Bob Could Stop On A Dime

Unfortuneately, others could not. Tired of rear-end repairs, Bob designed an automatic flasher that uses a pressure sensor in the brake line to measure the pressure applied to the brake pedal. The sensor output controls the rate of a 555 multivibrator chip, which in turn drives a high-power MOSFET in series with the brake lights. The harder Bob brakes, the faster his brake lights flash, and hopefully the harder the people behind him brake.

For Bob Walter's complete instructions on how to build a brake warning system, go to http://www.designnews.com/contents/pdf/gadget102504.pdf.