Coin acceptor/rejector

Claim 2

A coin testing device comprising: an oscillator producing a signal of a particular frequency at a relatively high Q and of a narrow band; a resonating sensing circuit including at least one coil disposed, so that a coin to be tested will particularly change and determine the resonance frequency of the sensing circuit, when having a particular disposition with respect to the coil; the sensing circuit being connected electrically to be energized by the oscillator without inductive coupling through said coil; the sensing circuit having a narrow response characteristic band about said resonance frequency, when sensing a coin, the oscillation frequency being in said band; the sensing circuit having a frequency response band remote from said oscillation frequency band when no coin is in its sensing range; and circuit means connected to said sensing circuit for detecting the response of the circuit to the oscillations in the presence or absence of a coin.

Claim 3

A coin testing device as in claim 1, wherein the circuit means includes an amplitude detector/discriminator for detecting whether the voltage of the sensing circuit has a particular amplitude within a narrow range in representation of a particular type of coin to be detected.

Claim 4

A coin testing device as in claim 1, wherein the sensing circuit is a tank circuit, the circuit means connected to be responsive to the amplitude of the voltage across the tank circuit.

Claim 5

A coin testing device as in claim 2, the circuit means including comparator means defining a detection band for response to said amplitude.

Claim 6

A coin testing device as in claim 1, wherein the oscillation frequency equals the resonance frequency of the sensing circuit when a coin is adjacent thereto.

Claim 7

A coin testing device as in claim 1, wherein the oscillation frequency is slightly higher than the peak frequency of the resonance band of the sensing circuit when a coin is adjacent thereto.

Claim 8

A coin testing device as in claim 1, the sensing means including at least one flat spiral coil having outer diameter about equal to the diameter of a coin to be detected, the particular disposition being a concentric one as between the coin and the coil.

Claim 9

A coin testing device comprising: an oscillator including a first tuned circuit with at least one coil for producing an oscillator signal at a relatively high Q and having the frequency of the resonance frequency of the tuNed circuit; a second tuned circuit including at least one coil and connected to be energized by the oscillator so that a sensing voltage is derivable from the second tuned circuit whose amplitude depends on the frequency of the oscillator; the respective resonance frequences of said first and second tuned circuit having a particular difference when no coin is in the vicinity of the coil of either of the tuned circuits; a particular type of coin when in particular juxtaposed disposition to one of the coils causing a change in the resonance frequency of the tuned circuit to which the coil pertains, the change being operative to diminish said difference so that said amplitude assumes increased value; and circuit means providing for a particular amplitude detection band and connected to the second tuned circuit to determine whether or not said increased amplitude falls into said detection band.

Claim 10

A coin testing device comprising: an oscillator including a first tuned circuit with at least one coil for producing an oscillator signal at a relatively high Q and having the frequency of the resonance frequency of the tuNed circuit; a second tuned circuit including at least one coil and connected to be energized by the oscillator so that a sensing voltage is derivable from the second tuned circuit whose amplitude depends on the frequency of the oscillator; the respective resonance frequences of said first and second tuned circuit having a particular difference when no coin is in the vicinity of the coil of either of the tuned circuits; a particular type of coin when in particular juxtaposed disposition to one of the coils causing a change in the resonance frequency of the tuned circuit to which the coil pertains, the change being operative to diminish said difference so that said amplitude assumes increased value; and circuit means providing for a particular amplitude detection band and connected to the second tuned circuit to determine whether or not said increased amplitude falls into said detection band.

Claim 11

A coin testing device as in claim 8 wherein the other one of said coils has disposition so that the coin may pass in its vicinity where upon said difference is increased.

Claim 12

A coin testing device as in claim 9, wherein the coils of the first and second circuits are located along a path for a coin, in close proximity to each other but in magnetically decoupled relationship.

Claim 13

A coin testing device as in claim 8, wherein the oscillator includes two emitter - coupled transistors with a common current source, and a feedback circuit from the collector of one of the transistors to the base of the other one of the transistors, the oscillator further including a first tank circuit in the collector circuit of one of the transistors as the first tuned circuit second tuned, while the circuit is a second tank circuit connected to the collector of the respective other one of the transistors.

Claim 14

A coin testing device as in claim 10, including a temperature-dependent bias for the transistors, the circuit means including means for tracking the temperature dependency of the oscillator and of the bias.

Claim 15

A coin detector as in claim 11, wherein the circuit means includes means for amplitude tracking of the detection band.

Claim 16

A coin detector, comprising: an oscillator producing a signal of a particular frequency; sensing means connected to the oscillator including at least one circular flat spiral coil having at least approximately the same diameter as the coin to be detected, and being disposed so that the coin will pass the coil coaxially, whereupon the coil as coupled to the coin assumes a particular inductivity; and circuit means connected to be responsive to the voltage across the coil for detecting the coin.

Claim 17

A coin detector, comprising: an oscillator producing a signal of a particular frequency; sensing means connected to the oscillator including at least one circular flat spiral coil having at least approximately the same diameter as the coin to be detected, and being disposed so that the coin will pass the coil coaxially, whereupon the coil as coupled to the coin assumes a particular inductivity; and circuit means connected to be responsive to the voltage across the coil for detecting the coin.

Claim 18

A coin detector as in claim 14, wherein the oscillator includes also at least one spiral coil, the spiral coils being mounted along a travel path for the coin to be subjected to similar environmental conditions, the coil of the sensing means and the coil of the oscillator being decoupled electromagnetically.

Claim 19

A coin detector as in claim 14, wherein the sensing means includes at least two coils, each being of spiral configuration and of similar diameter and coaxially disposed to each other, so that the coin passes between them.

Claim 20

A coin detector as in claim 14, wherein the circuit means includes a capacitor connected to the coil and completely therewith a resonance circuit, whose resonance band includes the oscillation frequency.

Claim 21

A coin detecting device comprising: an amplifier with double-ended output, and an input; a first tuned circuit connected to one of said outputs, a feedback circuit between said one output and said input for establishing an oscillator, whose frequency is determined by the first tuned circuit; a second tuned circuit connected to the other one of said outputs, one of said first and second tuned circuits located so that a coin to be detected and when in particular disposition to the one tuned circuit materially determines its tuned frequency, being the same or approximately tHe same frequency as the frequency of the other one of the tuned circuits; and circuit means connected to the second tuned circuit for detecting the amplitude of a signal developed by the second tuned circuit upon oscillation of the oscillator.

Claim 22

A coin detecting device comprising: an amplifier with double-ended output, and an input; a first tuned circuit connected to one of said outputs, a feedback circuit between said one output and said input for establishing an oscillator, whose frequency is determined by the first tuned circuit; a second tuned circuit connected to the other one of said outputs, one of said first and second tuned circuits located so that a coin to be detected and when in particular disposition to the one tuned circuit materially determines its tuned frequency, being the same or approximately tHe same frequency as the frequency of the other one of the tuned circuits; and circuit means connected to the second tuned circuit for detecting the amplitude of a signal developed by the second tuned circuit upon oscillation of the oscillator.

Claim 23

A coin detector as in claim 18, wherein the circuit means includes an amplitude band detector means, the amplitude of the signal developed by the second tuned circuit, when sensing a proper coin falling into that band.

Claim 24

A coin detector as in claim 18, wherein the second tuned circuit is tuned to a frequency relative to the oscillation frequency, so that the amplitude of the signal varies significantly for small differences in one of the parameters of the second tuned circuits.

Claim 25

A coin detector as in claim 18, the circuit means including a pair of comparators biased for slightly different changes of state to establish an amplitude detection band, the bias being provided through circuitry from a voltage source, being the same source operating said amplifier to obtain mutual tracking of the band and of the signal.

Claim 26

A coin detector as in claim 18, wherein the resonance frequency of the first tuned circuit is higher than the resonance frequency of the second tuned circuit with no coin influencing either tuned circuit, the particular disposition of a proper coin being in the vicinity of the second tuned circuit chaning the resonance frequency of the second tuned circuit to a value close to the resonance of the first tuned circuit.

Claim 27

A coin detector as in claim 18, wherein the resonance frequency of the second tuned circuit is higher than the resonance frequency of the first tuned circuit with no coin influencing either tuned circuit, the particular disposition of a proper coin being in the vicinity of the first tuned circuit changing the resonance frequency of the first tuned circuit to a value close to the resonance of the second tuned circuit, so that the oscillator frequency is altered accordingly.

Claim 28

A coin testing device comprising: an oscillator including a first tuned circuit with at least one coil for producing an oscillator signal at a relatively high Q and having the frequency of the resonance frequency of the tuned circuit; a second tuned circuit including at least one coil and connected galvanically to the oscillator to be energized therefrom, while the coils of the two tuned circuits are spaced apart to be magnetically decoupled; each of said two circuits having a particular resonance frequency band, said bands being spaced apart when no coin is in the vicinity of either coil of the tuned circuits; a particular type of coin when in particular juxtaposed disposition to one of the coils causing the frequency bands to be shifted into at least partially overlapping disposition; first circuit means connected to said second tuned circuit to derive therefrom a sensing voltage whose amplitude depends on the relative disposition of said bands, increasing with increasing overlap; and second circuit means connected to the first circuit means and providing for a particular amplitude detection band to determine whether or not said amplitude as derived falls into said detection band.

Claim 29

A coin testing device comprising: an oscillator including a first tuned circuit with at least one coil for producing an oscillator signal at a relatively high Q and having the frequency of the resonance frequency of the tuned circuit; a second tuned circuit including at least one coil and connected galvanically to the oscillator to be energized therefrom, while the coils of the two tuned circuits are spaced apart to be magnetically decoupled; each of said two circuits having a particular resonance frequency band, said bands being spaced apart when no coin is in the vicinity of either coil of the tuned circuits; a particular type of coin when in particular juxtaposed disposition to one of the coils causing the frequency bands to be shifted into at least partially overlapping disposition; first circuit means connected to said second tuned circuit to derive therefrom a sensing voltage whose amplitude depends on the relative disposition of said bands, increasing with increasing overlap; and second circuit means connected to the first circuit means and providing for a particular amplitude detection band to determine whether or not said amplitude as derived falls into said detection band.

Claim 30

A testing device as in claim 24, wherein the bands overlap with coinciding centers when a particular type of coin is adjacent to the one coil.

Claim 31

A testing device as in claim 24, wherein the peak frequency of the oscillation band is slightly higher than the peak frequency of the band of the second tuned circuit when a particular type of coin is adjacent to the one coil.

Claim 32

A testing device as in claim 24, the coils including at least one flat spiral coil having outer diameter about equal to the diameter of a coin to be detected, the particular disposition being a concentric one as between the coin and the coil.

Claim 33

A testing device as in claim 24, wherein the oscillator includes two emitter - coupled transistors with a common current source, and a feedback circUit from the collector of one of the transistors to the base of the other one of the transistors, the oscillator further including a tank circuit as the first tuned circuit and connected in the collector circuit of one of the transistors, while the second tuned circuit is a second tank circuit connected to the collector of the respective other one of the transistors.