Coin tester having a pair of induction coils

Claim 2

A coin tester comprising at least one pair of self-induction coils, a pair of oscillators respectively connected to said selfinduction coils, means defining a coin track extending through the fields of said self-induction coils, and means for causing the oscillation of only one of said oscillators to temporarily cease in response to passage of an acceptable coin along said coin track and for causing the oscillations of both of said oscillators to temporarily cease or for causing the oscillations of both of said oscillators to be uninterrupted in response to passage of another object along said coin track.

Claim 3

A coin tester as claimed in claim 1, further comprising rectifiers, each of which is adapted to rectify the oscillations of one of said oscillators and supply a pulse in the event of temporary cessation of said oscillations, and a logic circuit adapted to transmit a coin acceptance pulse only if only one of said rectifiers supplies a pulse to said logic circuit within a predetermined time which is at least equal to the time required by an object to pass through said coin track for traversing the fields of said self-induction coils and is smaller than the time interval between successively inserted coins.

Claim 4

A coin tester as claimed in claim 2, wherein said logic circuit comprises a univibrator a time constant within the limits of said time, a multivibrator, means for resetting said multivibrator, after operation thereof, with a delay which is also within said time limits but which exceeds the time constant of said univibrator, differential circuit means for differentiating the output voltage of said univibrator, an inverter for the output voltage of said differential circuit means, and an AND gate, said AND gate having two inputs, and one of said outputs being connected to the output of said multivibrator and the other being connected to the output of the inverter and having an output which delivers the coin acceptance signal.

Claim 5

A coin tester as claimed in claim 3, fUrther comprising an OR gate, means for connecting each of the two inputs of said OR gate to the output of one of said rectifiers, and means for connecting the output of the OR to the input of said multivibrator and of said univibrator.

Claim 6

A coin tester as claimed in claim 1, wherein one pair of said self-induction coils and of said oscillators is provided for each of a plurality of coin denominations, pairs of self-inductor coils being disposed at a distance from each other along said coin track.