Coin detection and validation means

Means to distinguish genuine coins from other coins comprising:

• means forming a coin path along which a coin to be distinguished moves,
• first and second coils positioned adjacent to the coin path in position to have mutual inductance therebetween and their fields when energized affected by the presence of a coin moving along the coin path adjacent thereto, means connecting the first and second coils in series,
• first and second capacitors connected respectively across the first and second coils to form respective first and second tank circuits therewith, the resonant frequencies of the respective first and second tank circuits being a function of the inductance and capacitance associated therewith,
• means to simultaneously establish a charge on the first and second tank circuit, means to simultaneously disconnect the means to establish a charge when a coin is positioned in the fields thereof to thereby produce a damped wave output signal, and
• output means connected to at least one of the tank circuits where the output signal is produced, the output signal having characteristics that are representative of the coin in the fields of the first and second tank circuits when the charging means are disconnected therefrom.

Means for determining the genuineness of a coin comprising a control circuit including first and second tank circuits each having an inductor and a capacitor, the inductors being positioned to have mutual inductance therebetween when a signal si applied thereacross, said first and second tank circuits having an output, means to apply an electric charging pulse across the first and second tank circuits whereby a charge is established on the tank circuits which charge ceases when the pulse ends thereby producing a damped wave output signal on the output of the tank circuits, means in the control circuit for establishing a reference voltage level, other means in the control circuit for selecting a predetermined portion of the damped wave output signal for evaluation including a pair of comparator circuits each having a first input connected to the reference voltage level and each having a second input, the comparator circuits establishing a voltage level for the selected predetermined portion of the damped wave output, first and second digital potentiometers each having a first connection to a respective second input of one of the comparator circuits and a control connection, a microprocessor having a first output for producing the charging pulse for applying to the first and second tank circuits to produce the damped wave output signal and second and third outputs connected respectively to the control connections of the respective first and second digital potentiometers, the first and second digital potentiometers establishing predetermined relationships between voltage levels of the two selected predetermined portions of the damped wave output signal to compare to the reference voltage level.

A method of determining the acceptability of a coin in a coin testing device comprising the steps of:

• establishing a circuit that includes at least two series connected tank circuits each having an inductor and a capacitor, the inductors being positioned to have mutual inductance therebetween,
• applying a charging pulse with fixed characteristics across at least one tank circuit to produce a damped wave driving signal upon removal of said charging pulse;
• providing a path for coins to be tested through the resultant magnetic field of said damped wave driving signal to cause changes therein;
• detecting said damped wave driving signal;
• preselecting at least one proportion of the changed driving signal;
• comparing said preselected proportion of the changed driving signal to at least one fixed reference voltage level;
• and
• determining whether said comparison indicates an acceptable coin.

In a coin testing device for providing and maintaining selectivity of a known population of at least one coin type:

• means for produce a damped wave using at least one tank circuit having an inductor and a capacitor;
• means to apply a pulse to charge said tank circuit, termination of said pulse producing the damped wave;
• means to pass coins to be tested through the magnetic field said inductor when the pulse applied thereto is terminated;
• means to detect a selected portion of the damped wave signal produced by said coins passing through said magnetic field;
• means to select at least one portion of said damped wave signal;
• means to compare the amplitude of the selected portion of said damped wave signal to a reference voltage level;
• means to determine whether said comparison indicates an acceptable coin;
• and
• means to amplify the selected portion of said damped wave signal in a direction to maintain selectivity of at least one coin type.

Means to distinguish genuine coins from others coins comprising:

• means forming a coin path along which a coin to be distinguished moves,
• first and second coils positioned adjacent to the coin path in position to have their fields when energized affected by the presence of a coin moving along the coin path adjacent thereto,
• first and second capacitors connected respectively across the first and second coils to form respective first and second tank circuits therewith, said first and second tanks circuits being connected in series and the first coil being connected in series aiding relationship with the second coil, the resonant frequencies of the respective first and second tank circuits being a function of the inductance and capacitance associated therewith,
• means to establish a charge on the first and second tank circuit, means to disconnect the means to establish a charge when a coin is positioned in the fields thereof to thereby produce a damped wave output signal, and
• output means connected to at least one of the tank circuits where the output signal is produced, the output signal having characteristics that are representative of the coin in the fields of the first and second tank circuits when the charging means are disconnected therefrom.

Means to distinguish genuine coins from others coins comprising:

• means forming a coin path along which a coin to be distinguished moves,
• first and second coils positioned adjacent to the coin path in position to have their fields when energized affected by the presence of a coin moving along the coin path adjacent thereto,
• first and second capacitors connected respectively across the first and second coils to form respective first and second tank circuits therewith, the resonant frequencies of the respective first and second tank circuits being a function of the inductance and capacitance associated therewith, the first coil of the first tank circuit being positioned on one side of the coin path and the second coil of the second tank circuit being positioned on the opposite side of the coin path from the first coil such that the fields of the first and second coils overlap in the coin path,
• means to establish a charge on the first and second tank circuits, means to disconnect the means to establish the charge when a coin is positioned in the fields thereof to thereby produce a damped wave output signal, the means to disconnect the charging means being connected to the first tank circuit, and
• output means connected to the second tank circuit where the output signal is produced, the output signal having characteristics that are representative of the coin in the fields of the first and second tank circuits when the charging means are disconnected therefrom.