摘要 |
An encoder for a wheel or other devices with relative movement comprises in the use of a printwheel, a linear Hall-effect sensor and magnet mounted in a non-ferrous metal shaft with a flux conducting spiral ring molded in the printwheel and encircling the shaft. The angular position of the printwheel is absolutely determined by the magnitude of the signal relative to the transition point of the spiral. The values are converted to digital information and stored in non-volatile memory for comparison to the values measured as the wheel is positioned during operation of the wheel. In another embodiment, a second Hall-effect sensor is placed on the shaft opposite the first sensor to provide an enhanced signal. |