Electronic pulse counter and indicator for agricultural machinery - has programmable counter driven from wheel mounted magnetic switch

摘要

The electronic pulse counter and indicator can be used on agricultural vehicles such as tractors and harvesters to calculate ground areas worked for hiring and other costings. A sealed permanent magnet is attached to a wheel of the vehicle and a magnetic switch on the axle housing operates a counter. The pusher (4) is connected to an encapsulated reed relay whose contact provides a pulse for an integrated circuit counter (9). A voltage stabilisation circuit comprising a zener diode, resistors and a capacitor connects the vehicle battery to the counter. The counter is programmable via push-buttons so that constants such as the circumference of the wheel, can be entered. An eight-digit display (17) comprising seven-segment indicators, is housed in a shock resistant plastics case.