INSPECTION DEVICE OF REMOTE TELEPHONE SET

摘要

PURPOSE:To inspect automatically a talking function of a telephone set installed remotely through the use of a talking line by providing respectively a speaker and a microphone near a handset of another telephone set. CONSTITUTION:An exchange 1 transmits a signal of a frequency A to a channel 4 by closing a switch 2. A telephone set 5 receiving the signal supplied the sound wave of a receiver 6 to a detector 8 via a microphone 7. Then the detector 8 closes a switch 9 when the frequency and a voltage level are in compliance with the standards. Then a signal of a frequency B is transmitted to a channel 4 via a speaker 12 and a transmitter 11. Then a detector 13 of the exchange 1 checks whether or not the frequency and the voltage level of the received signal of the frequency B match with the standards. The talking function of a telephone set installed at a remote location is checked automatically by using a talking line in the way.