Is it worth building soemthing based on exisitng speedo ideas? a rotating magnet pulls the needle against a spring.. Why not use the rotating magnet to generate pulses, or to generate an average DC voltage (which could be fed into a PLL VCO) Just batting ideas around. Des >>> Wagner Lipnharski 7/13/99 12:32:07 am >>> Does anyone knows some supplier for "speed transducer" to be installed at the car speedometer cable? My circuit needs to receive a frequency proportional to the car speed, and I need to find out ... well... cheap sensors... :) Thanks Wagner Lipnharski http://www.ustr.net