| 摘要 |
PURPOSE:To reduce greatly the amount of consumption of a power source for a terminal equipment, by making the power supply of the terminal device only when the signal is produced between the MODEM and the terminal equipment. CONSTITUTION:The input and output are applied to the signal detector 9 provided at the MODEM1 against the terminal equipment 2 of the modulator/demodulator part 8, and the detection output is produced by the carrier wave detection signal supplied from the part 8. This state is kept while the transmission request signal is transmitted from the equipment 2. This detection output drives the relay 15 and then turns on the relay contact 13. As a result, the power supply is made for the equipment 2 regardless of the off state of the switch 10 as long as the switch 12 of the equipment 2 is kept on. Thus the equipment 2 is kept active while the data signal is transmitted and received. The detection output of the detector 9 is extinguished with the end of transmission/reception, and then the relay 15 is released to cut off the power supply of the equipment 2. |
