| 摘要 |
PURPOSE:To realize both the generation and transmission of an optional interrupted pattern from a sound source and then transmit various types of ringing tones, by unifying various sound sources classified by the interrupted pattern into a single pattern and then installing a transmission pattern setting circuit. CONSTITUTION:A call of incoming connection is generated when the telephone TEL is under the ON-HOOK state, and thus the call signal transmission request information is applied to the terminal P. Then the type of call signal and the switch driving information are written into the pattern selection memory MEM, and one of the signal patterns T1-T4 is selected by the pattern selection circuit SEL. The selected signal is delayed by the delay circuit DH. Then a logic is obtained between the signal delayed by the circuit DH and the signal selected by the circuit SEL, and a control is given to the switch circuit SW1 and SW2 that interrupt the signals supplied from the CR signal tone source CRG. Then the signal from the source CRG is transmitted to the ring trip circuit DET in the form of a call signal. At the same time the circuits SW1 and SW2 are broken for the period from the changing point of the output of the circuit SEL to the charging point of the delay output to transmit various types of call signals. |
