TALKING CONTROL SYSTEM IN PUBLIC TELEPHONE SET

摘要

PURPOSE:To attain ease of discrimination of mis-operation and incorrect operation by disabling transmission if a dial number is an inhibited number, cutting off a DC loop circuit when incorrect number to disable reception and transmitting an audible tone to a receiver. CONSTITUTION:A control section CNT judges the presence of a deposited coin in response to the detection output of a coin detection circuit CCD and when it is judged to be an inhibited number, restoration control is applied to a block relay TS only, a contact ts1 by-passes a transmitter T to disable the transmission. Further, when it is judged as an incorrect number, a switch SW is controlled to open a DC loop circuit forcibly for a prescribed time, the restoration control to the by-pass relay SS is attained, the transmission/reception by a contact (ss) is disabled, an oscillator OSC is controlled, an audible tone signal corresponding to a busy tone is generated and transmfitted to a receiver R of a talking circuit TKC. Thus, when the inhibited number is dialed, the transmission is disabled, and when an incorrect number is transmitted or a coin is stored incorrectly, an audible tone is listened to.