| 摘要 |
<p>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.</p> |
