Abstract: A detector device adapted to be used for detecting coins and other metal objects for various purposes including to distinguish between genuine and non-genuine or counterfeit coins, the subject detector device includes an electric tank circuit having a coil through which, or adjacent to which, an object or coin to be detected moves, apparatus to electrically shock the tank circuit to produce an output representative of the object or coin and represented as a damped wave signal the frequency and shape of which depends on the electrical characteristics associated with the tank circuit and on the physical and electric characteristics of an object or coin being detected, and a detector circuit operatively connected to the tank circuit including circuit elements connected to respond to one or more characteristics of the damped wave output.

Abstract: An apparatus for detecting objects such as coins and the like and for generating signal responses that depend on the metal content or other characteristics of the object or coin, which apparatus includes a detector circuit including an oscillator device having a coil portion for producing a frequency change due to the presence of an object or coin in the field thereof, said detector circuit producing output responses to represent the presence of objects or coins having certain preselected characteristics, and other control circuits including a circuit portion responsive to the output responses of said detector circuit for inhibiting the operation of such control circuits. The present device may also include a coin handling apparatus which prevents return to a customer of an object or coin that has characteristics that are not acceptable for vending, change making, or other functions.

Abstract: A control circuit for a pay phone including a coin unit where money is deposited and validated, an entry circuit having a first input connected to the coin unit for entry of amounts deposited, a second input to the entry circuit for communicating thereto call price information, a control element operable in response to deposits of an amount at least equal to the call price for enabling the customer to dial his call and to enable phone communication with the dialed phone, and apparatus to control payback of excess amounts deposited. The control circuit is preferably powered by a rechargeable energy source that may optionally be connected to the telephone line to derive charging current therefrom to maintain the charge on the energy source. The present control circuit may employ optical or other forms of couplers to establish connections to communicate the dialing mechanism and telephone handset with its associated transmission controls to the telephone line.