Telephone pay station providing limited coin-free calls

Abstract From the Canadian patent

A circuit for providing coin-free dialing of a predetermined number of digits is provided for use with a telephone pay station. A signal generator to provide a pulse in response to each telephone number dialed is included. The signal after counting a predetermined number of pulses. A phantom coin circuit is connected to the counter and to the telephone central office for simulating the existence of a coin to the central office to cause the central office to accept the dialing signals. Another circuit is provided for prevention of fraudulent pushbutton chain-dailing. This fraud prevention circuit includes a timing circuit and a latch which effectively shunts the pushbutton dial if …