Design of Infrared Digital Tachometer
This paper introduces the design of the non-contact method to measure the rotational speed. Compared with the traditional mechanical method and magnetic method, more convenient and efficient for future speed measurement is of great significance with measure the rotational speed of the object with a photoelectric. The design circuit includes photoelectric conversion circuit, 1 s pulse generation circuit, 60 s frequency multiplication circuit, counting latch circuit and decoding display circuit. Pulse waveforms is produced by photoelectric conversion circuit, after a Schmitt trigger wave shaping, the pulse waveform excite latch working, by the circuit latch, decoding, display, finally the mechanical speed will dynamic display on the common cathode 7-segment digital tube.
KeywordsPhotoelectric conversion 1 s Pulse generating circuit 60 s Timing and latching circuit Decoding and displaying circuit
This research was supported by the Tianjin natural science fund (13JCYBJC15800).
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