| 摘要 |
PURPOSE:To miniaturize a telephone set by executing any one of closing/opening of a telephone line and the sending of a dial pulse signal by a photocoupler. CONSTITUTION:Any one of the opening/closing of the telephone line and of a dial pulse signal is executed by the photocoupler. For instance, a signal from a mobile set is received by a transmitting/receiving antenna 15 and a high frequency receiving circuit 13 and outputted to a control means 12 through a detecting/low frequency amplifier circuit 10 and the control means 12 turns on a telephone line closing photocoupler 7 through a transistor(TR) 9, closes the telephone line and sets up a speaking enable state. Since the closing/opening of the telephone line is executed through the photocoupler without using a relay, insulation can be secured and the whole telephone set can be miniaturized because the photocoupler is compact and lightweight as a part. |
