Zero speed sensing capability is offered by the HE615300 geartooth speed sensor module. The unit, which comes complete with integral connector, uses a single, solid-state, Hall-effect sensor coupled to self-calibrating, peak-to-peak detection circuitry to give precise switch point accuracy. The module is designed to sense rotational speed of ferrous gear-type targets such as web speed gears, power transmission gears, conveyor speed and position, and other similar gear-based shaft encoders. No external electronics are required to further process the signal. An open-collector output is capable of sinking 20 mA and driving signals over wire lengths of up to 50 feet. The device operates from 4.5 to 24 vdc.