Duncan Industries Parking Control Systems Corp.

Daniel P Kasuba

Ralph H Carmen

Joseph H Sutton

A coin-sensing system wherein at least two sensor coils are electrically connected in series and physically arranged so that a coin deposited into the apparatus may pass sequentially through each sensor coil and thereby change the impedance of the coil. A sensor oscillator circuit incorporates the sensor coils to output an oscillating sensor signal at a frequency dependent on the impedance of the sensor coils. Counters measure the frequency of the sensor signal to obtain a frequency signature for the deposited coin which can be compared with frequency signatures of valid coins. The oscillator circuit may produce a lower frequency oscillating sensor signal or a higher frequency oscillating sensor signal and electronic switches are included in the circuit for switching from one of the frequency levels to the other after the deposited coin encounters a first sensor coil and before the deposited coin encounters a second sensor coil.

Growing community of inventors

Harrison, AK, United States of America

Daniel P Kasuba