• Gem Electronics System

Gear Tooth Sensor

Gem Electronics System manufactures Gear Tooth Sensor, Model 55075. It makes use of the hall element to sense the variation in flux found in the air gap between a magnet and passing ferrous gear tooth. It will detect the first edge of the next tooth immediately after power on. The ability to convert the repetitive passing teeth to an electrical impulse has been sought for many decades. Purely mechanical systems have been used with the attendant issue of wear and failure limiting its use to low speed and low duty cycle applications. Peak detection, peak hold, and level comparison are all done digitally. The maximum and minimum hall signal that corresponds to the last gear tooth and valley is then remembered indefinitely without the drift associated with analogue techniques. The level comparison then adapts to the last peak. This creates true zero speed adaptive speed sensor. .