摘要 |
A coin discriminator system for use in an electronic parking meter. A deposited coin is inserted in the electronic parking meter and a chute guides the deposited coin past an inductor. The deposited coin causes a momentary change in the value of inductance of the inductor. A phase lock loop electronic circuit has an input connected to the inductor and the phase lock loop electronic circuit. The correction signal compensates for the change in the value of inductance of the inductor and has a wave shape unique to the deposited coin. A microprocessor receives the correction signal waveform for comparison to a plurality of predetermined wave shapes of a plurality of known coins to thereby identify the deposited coin. The plurality of predetermined wave shapes are stored in a memory connected to the microprocessor.
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