Coin-validating arrangement
AssigneeCoin Controls Limited
InventorDennis Wood
Life of this patent
Estimating the term…
Abstract
A coin-validating arrangement including a coin guide path and a sensing coil disposed adjacent said path, the coil being part of a tuned circuit coupled into a negative feedback path of an amplifier whereby to produce a phase shift sufficient to result in positive feedback and oscillation in said amplifier in the absence of a correct coin at the region of said path adjacent said coil, the tuned circuit being so arranged that on passage of a correct coin past said region the oscillation is quenched or reduced in amplitude, a circuit being provided for detecting the quenching or amplitude reduction of said oscillation, and a threshold detector provided for responding to said detecting circuit and opening an acceptance gate for the said correct coin.
Claims18
A coin-validating arrangement, comprising
- (a) coin guide means defining a coin guide path (3);
- (b) oscillation circuit means including
- (1) fixed biased amplifier means (11) having input and output terminals;
- (2) tuned circuit means including at least one coil arranged adjacent said coin guide path, said tuned circuit means being connected between said amplifier output and input terminals to define a negative feed back path;
- and
- (3) means including a variable resistor (VR1) for applying to said tuned circuit means a potential normally producing a phase shift sufficient to result in positive feedback in said amplifier means and oscillation of said oscillation circuit means, said oscillation circuit means being operable to a non-oscillating quenched condition when a given coin having predetermined physical characteristics is temporarily positioned adjacent said coil;
- (c) normally closed acceptance gate means (7) arranged in said coin path;
- (d) detecting means for detecting the quenching of the oscillations of said oscillation circuit means by said given coin;
- and
- (e) means operable by said detecting means when said oscillation circuit means is in the quenched condition for opening said acceptance gate means, thereby to permit the passage of the given coin therethrough.
A coin-validating arrangement, comprising
- (a) coin guide means defining a coin guide path (3);
- (b) oscillation circuit means including
- (1) amplifier means (11) having input and output terminals;
- and
- (2) tuned circuit means including at least one coil arranged adjacent said coin guide path, said tuned circuit means being connected between said amplifier output and input terminals to define a negative feedback path, said tuned circuit means being normally operable to produce a phase shift sufficient to effect positive feedback and operation of said oscillation circuit means to an oscillating condition, said tuned circuit means being operable when a coin having given physical characteristics is adjacent said coil for quenching oscillation of said oscillation circuit means;
- (c) normally closed acceptance gate means (7) arranged in said coin path;
- (d) detecting means for detecting the quenching of the oscillations of said oscillation circuit means by said given coin, said detecting means including
- (1) a detector capacitor (C6);
- (2) rectifier circuit means (D3, D4) for charging said detector capacitor, said rectifier circuit means including an input terminal connected with the amplifier output terminal, and an output terminal connected with said detector capacitor;
- and
- (3) threshold detector means (12) connected with said detector capacitor, said threshold detector means being operable between a normal first condition when said oscillation circuit means is in the oscillating condition and said detector capacitor is charged to a given threshold level, and a second condition when said oscillation circuit means is in the quenched condition and the charge on said detector capacitor is less than said threshold level;
- and
- (e) means (6) operable when said threshold detector means is in its second condition for operating said acceptance gate means to the open condition, thereby to pass the given coin through said acceptance gate.
Dependencies are inferred from the claim text.