| 摘要 |
PURPOSE:To connect plural magneto telephone sets in parallel with a 2W magneto telephone line with simple constitution comprising only relays by controlling the ringing of a bell by a transmission line interrupting relay interrupting telephone sets other than a telephone set in transmitting state from a telephone line and an incoming bell stop relay grounding the bell control line of other telephone sets than a telephone set in a incoming state. CONSTITUTION:In detecting a call signal by 2W/5W converters 3a, 3b, a bell of telephone sets 21a, 21b rings. For example, in hooking off a handset of the telephone set 21a, a bell control line 6a is grounded, the bell of the said telephone set 21a is stopped, a relay C10 is activated at the same time, a bell control line 6b of the telephone set 21b is grounded by a relay contact c1, resulting that the bell of the telephone set 21b is also stopped. In hooking off the handset of the telephone set 21a, a hook switch signal line 8a is grounded by the off-hook, a relay A12 is activated and the telephone set 21b is disconnected from 2W magneto system telephone lines 1, 2 by relay contacts a1, a2. As a result, the bell of the telephone set 21b does not ring. |
