Abstract: Replenishing coins in a coin store associated with a coin handling device includes feeding a batch of coins from a bulk coin store to a receptacle near the coin handling device, delivering coins from the receptacle to the coin handling device and routing at least some of those coins from the coin handling device to the coin store associated with the coin handling device.

Abstract: A coin sensor performs time-domain eddy-current testing using an inductance in one arm of a Maxwell bridge which is driven by a bipolar square wave having randomly-selected intervals between transitions, the output of the bridge being sampled at a high frequency. A processor stores a model which receives the drive signal and adjusts coefficients of the model so that the output matches the sampled measurements. Acceptance criteria are applied to the adjusted coefficients for coin classification purposes.

Abstract: Replenishing coins in a coin store associated with a coin handling device includes feeding a batch of coins from a bulk coin store to a receptacle near the coin handling device, delivering coins from the receptacle to the coin handling device and routing at least some of those coins from the coin handling device to the coin store associated with the coin handling device.

Abstract: An electrical discharge produces an acoustic impulse, and a reflection of the impulse from the upper coin in a coin stack is sensed so that the level of the coin stack can be determined from the time taken for the reflection to be received. Alternatively, or additionally, the acoustic impulse can be used to detect coin jams, the presence and/or width of a coin store, the state of a coin routing gate or the quantity of a vendible product.

Abstract: A coin sensor performs time-domain eddy-current testing using an inductance in one arm of a Maxwell bridge which is driven by a bipolar square wave having randomly-selected intervals between transitions, the output of the bridge being sampled at a high frequency. A processor stores a model which receives the drive signal and adjusts coefficients of the model so that the output matches the sampled measurements. Acceptance criteria are applied to the adjusted coefficients for coin classification purposes.

Abstract: A coin validator tests a coin using a pair of coils coupled in an oscillator circuit which is arranged to drive both the coils concurrently at two separate frequencies without interference therebetween, each frequency signal being influenced by the presence of a coin. Preferably, the coils are connected in series in a feedback loop to form a first oscillator, and the second oscillator is coupled to the interconnection between the coils the other ends of which are effectively short circuited at the frequency of the second oscillator.

Abstract: An electrical discharge produces an acoustic impulse, and a reflection of the impulse from the upper coin in a coin stack is sensed so that the level of the coin stack can be determined from the time taken for the reflection to be received. Alternatively, or additionally, the acoustic impulse can be used to detect coin jams, the presence and/or width of a coin store, the state of a coin routing gate or the quantity of a vendible product.

Abstract: A device for validating a coin comprises an electro-magnetic sensor, means for monitoring a first signal generated by the sensor and means for deriving a measurement from a second signal generated by the sensor. The event of the first signal taking a predetermined threshold value is used to derive a measurement from the second signal.

Abstract: A coin diameter measuring circuit uses a pair of coils coupled in the feedback path of an oscillator so that the oscillator frequency depends on the inductances of the coils and the mutual inductance therebetween. The coils are switched between aiding and opposing configurations when the coin passes between them, the oscillator frequency in each configuration is measured, and the difference between the frequencies is determined to provide an indication of the mutual indictance of the coils and, thus, the diameter of the coin. Preferably, the diameter is determined by the difference between the measured mutual inductance with the coin present and the coin absent.

Abstract: An apparatus and method of validating coins involves taking two independent measurements of the tested item, and determining whether both measurements lie within respective ranges for a particular coin type, the range for at least one of the measurements being dependent upon at least one other measurement.

Abstract: Apparatus for validating items of value is described. The apparatus includes a measurement circuit including an inductor, the complex impedance of which varies in accordance with the interaction between a test item of value and a magnetic field within which the inductor is located. Circuitry is provided for extracting first and second periodic signals from the measurement circuit, and a circuit is provided for timing the interval between corresponding portions of the first and second periodic signals. A processing element then determines the value of a parameter related to at least one of the real and imaginary parts of said complex impedance, as a measure of the validity of said test item, from the outputs of the timing circuit.