Patent ID: 6335970
Filing Date: 2002-01-01
Classification: H04M

Abstract:
An automatic coin collection device for a payphone that is provided with no coin collection signal from a telephone line, comprising:a solenoid for being activated to collect coins so as to start to count time and begin telephone communication; a call tone detector connected to the telephone line for detecting a call tone on the telephone line; a voice detecting circuit connected to the telephone line for detecting a voice signal on the telephone line; a micro-controller for performing an analysis based on the detecting results of the call tone detector and the voice detecting circuit after a user has dialed the payphone to make a phone call, and for activating the solenoid to start to count time and begin telephone communication when a ring back tone on the telephone line disappears and a voice signal appears, or when no ring back tone is detected but a voice signal appears; wherein, the micro-controller determines whether there is a ring back tone or a busy tone appearing on the telephone line by analyzing a duration time of the call tone and activates the solenoid to start to count time and begin telephone communication when the detected ring back tone appearing on the telephone line has a duration time shorter than a predefined first duration time and a voice signal is detected on the telephone line or when there is a ring back tone appearing previously on the telephone line after determining that the detected ring back tone appearing on the telephone line has a duration time shorter than a predefined first duration time and a voice signal is detected in the telephone line; and after detecting that there is a voice signal appearing on the telephone line and if there has been no ring back tone appearing on the telephone line, the micro-controller performs an analysis to determine whether a call tone has appeared on the telephone line with a duration time longer than the first duration time, and if yes, starts to count time and begins telephone communication and activates the solenoid after a predefined first delay time, otherwise, starts to count time and begin telephone communication and activates the solenoid after a predefined second delay time.