| 摘要 |
<p>PURPOSE:To enable confirm and select the channel set at present by a remote control signal, by calling out the device where a set value is set to each of a plurality of channels, such as a telephone automatic transfer device, by means of a telephone set located at a remote distance. CONSTITUTION:The number transferred is set to each channel, 1-4, of a telephone number selection switch circuit 5 of a telephone automatic transfer device, normally the number set to the channel 1 is used, and a telephone set A incoming to a telephone set B can be made communicationable with other telepnone set D via a telephone set C via transformers LT1, 2. When the possessor calls out the telephone set C from the location of visit, the call out signal is detected at a line 8, a timer 15 is started via a photodetector CdS, a relay Y3 is driven to release the reset of a counter IC2. Multivibrators G7, 8 turn on for one second, the signal tone in 1kHz is transmitted from an oscillation circuit 14 to the line for the time, this is counted by the counter IC2 to be at ''1''. In this case, if the channel set to the counter IC1 is ''1'', the signal transmission is latched and the number of channel can be identified.</p> |
