摘要 |
A cutting cylinder of a newspaper press assembly has a magnet member mounted thereon. A semiconductor Hall effect pickoff is mounted in proximity to the cutting cylinder such that the magnet passes by this sensor in close proximity thereto once during each rotation of the cylinder. The output of the Hall effect sensor, which is in the form of pulses, is fed both to a non-inverting and an inverting amplifier. The outputs of the amplifiers are fed to a differential detector which provides an output only in accordance with the difference between the inputs fed thereto, thus eliminating common-mode inputs such as noise signals. The output of the differential detector is fed to a digital counter which provides a count of the input pulses representing the number of newspapers or the like detected by the sensor. The output of the digital counter in turn is fed to a readout device which provides a suitable readout of this count which may be in the form of a display.
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