Key telephone line circuit tone-on-hold arrangement
AssigneeBell Telephone Laboratories, Incorporated
InventorsRonald Joseph Angner, James Volney Lacy
Life of this patent
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Abstract
There is disclosed a circuit for generating tone signals from clocking signals present on each key telephone line circuit. The tone signals are transformer coupled onto the communication leads by an optional plug-in-board arrangement. In present installations music-on-hold is provided by connecting an external music source to each line card. There is also disclosed an arrangement for utilizing the optional plug-in-board to provide either tone-on-hold or music-on-hold by simply reversing a plug-in connector.
Claims11
A line circuit for use in controlling communication services between a telephone switching machine and a telephone station, said line circuit adapted for connection in parallel across the communication conduction pair between said switching machine and said telephone station and adapted for A-lead control from said station, said line circuit including
- hold and ringing control means,
- a source of clock signals,
- means controlled by said clock signals for detecting both A-lead signal changes, and communication lead signal changes and
- for comparing detected A-lead signals with detected communication lead signals, and
- for enabling selected ones of said hold or ringing control means,
- audio coupler means,
- means for generating from said clock signals a signal having a duty cycle, such that when said generated signal is applied to said audio coupler means a distinctive audio tone results, and
- means for optionally coupling said generated audio signal to said communication leads through said audio coupler when said hold means is enabled.
A line circuit for use in controlling communication services between a telephone switching machine and a telephone station, said line circuit adapted for A-lead control from said station, said line circuit means including
- hold and ringing control means,
- means for detecting A-lead signal changes, and
- communication lead signal changes, and operative
- for enabling a selected one of said hold or ringing means,
- means for receiving audio signals,
- means for optionally coupling said received audio signals to said communication leads when said hold means is enabled, said optionally coupling means including
- a first connector having contacts permanently connected to said communication conducting pair, and
- a second connector adapted to mate with said first connector in a first positional relationship when said received signal is to be provided to said communication pair when said hold means is enabled and to mate with said first connector in a second positional relationship when said received signal is not to be provided to said communication pair when said hold means is enabled.
An option board for use in conjunction with a key telephone line circuit board, said line circuit board having a set of terminals which serve to control the provision of first and second audio signals to a Central Office or PBX line connected thereto when the connected line has been placed in the hold mode, said option board comprising a first connector for mating with said set of terminals,
- circuitry for receiving said first and said second audio signals via said first connector and for extending said signals to said line circuit board via said first connector,
- a set of terminals connected electrically with said circuitry and said first connector, said terminals being connected in a manner such that when said terminals are cross-connected in a first manner said first audio signals are provided to said line circuit and when said terminals are cross-connected in a second manner said second audio signals are provided to said line circuit.
Dependencies are inferred from the claim text.