Coin discrimination system
First Claim
1. A coin-sensing apparatus 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 incorporating the sensor coils to output an oscillating sensor signal at a frequency dependent on the impedance of the sensor coils, and including counter means for measuring 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 improvement comprising first means in said circuit for outputting a lower frequency oscillating sensor signal, and second means in said circuit for outputting a higher frequency oscillating sensor signal, switch means in said circuit and means for operating said switch means for switching from one of said first and second means to the other of said first and second means after the deposited coin encounters a first sensor coil and before the deposited coin encounters a second sensor coil.
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Accused Products
Abstract
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.
118 Citations
9 Claims
- 1. A coin-sensing apparatus 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 incorporating the sensor coils to output an oscillating sensor signal at a frequency dependent on the impedance of the sensor coils, and including counter means for measuring 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 improvement comprising first means in said circuit for outputting a lower frequency oscillating sensor signal, and second means in said circuit for outputting a higher frequency oscillating sensor signal, switch means in said circuit and means for operating said switch means for switching from one of said first and second means to the other of said first and second means after the deposited coin encounters a first sensor coil and before the deposited coin encounters a second sensor coil.
- 7. A method for sensing coins to discriminate between valid and invalid coins wherein at least two sensor coils are electrically connected in series, arranging the coils so that a coin passes sequentially through each sensor coil and thereby changes the impedance of the respective coils, providing a sensor oscillator circuit incorporating the sensor coils for outputting an oscillating sensor signal at a frequency dependent on the impedance of the sensor coils, counting the frequency of the sensor signal to obtain a frequency signature for the coin, comparing that frequency signature with frequency signatures of valid coins, providing a first means in said circuit for outputting a lower frequency oscillating sensor signal, providing a second means in said circuit for outputting a higher frequency oscillating sensor signal, and switching from one of said first and second means to the other of said first and second means after the deposited coin encounters a first sensor coil and before the deposited coin encounters a second sensor coil whereby the signature measurements of the respective coils are taken at different frequencies.
Specification