Automatic telephony; a comprehensive treatise on automatic and semi-automatic systems (1921)
Smith, Arthur Bessey, b. 1875, Campbell, Wilson Lee · New York : McGraw-Hill · leaf 188
ions. line switch is removed and the private multiple opened between eachconnector bank. Each private contact is now connected through a1200-ohm coil to negative battery. From the foregoing it is evident thatseveral persons (depending upon the number of connectors) can get in online 11 at the same… … #??Z/ Telephone- Test ■t-L ±L To Test-Connector Yale Lock ~L Fig. 164.—Supervisors telephone circuit. 22 and connected to a test connector. This enables the supervisorywatchman to cut in on any line in the plant, even though it is busy.The ringer remains across line 22 at all times, therefore an…
Telephone
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