Line circuit for use with a key telephone system
AssigneeAkzona Incorporated
InventorsGerald J. Yachabach, Regis B. Mellon
Life of this patent
Estimating the term…
Abstract
There is provided a line circuit for connection to a key telephone system for indicating an incoming call, a call placed on hold, and an answered call. There is further provided a means for automatically indicating that the incoming call has been placed on hold for a predetermined time period. There is further provided a solid state device which switches telephone instrument lamp current for visual indication of the various line circuit operations.
Claims18
A line circuit for use with a key telephone system comprising:
- first and second input terminals adapted to be respectively connected to tip and ring conductors;
- a hold circuit including a hold impedance adapted to be connected across first and second input terminals during the hold condition, said hold circuit including a first switch means for activating said hold circuit;
- a first output terminal adapted to be connected to a indicating means;
- the indicating means adapted to provide a first signal during said hold condition;
- timing means including an analogue circuit for initiating the indicating means at a predetermined time after said hold circuit has been activated;
- the indicating means providing a second signal after said predetermined time.
A line circuit for use with a key telephone system comprising:
- first and second input terminals adapted be connected to associated tip and ring conductors;
- a hold impedance;
- hold switch means connected to said hold impedance for connecting said hold impedance across said first and second input terminals during the hold condition;
- a solid state switch having first and second power electrodes and a control electrode;
- said first power electrode adapted to be connected to a visual indicator;
- said second power electrode adapted to be connected to a source of electrical energy;
- first switch means connected to said control electrode for connecting said control electrode to a first signal source having a characteristic for indicating a ringing signal on the visual indicator;
- second switch means connected to said control electrode for connecting said control electrode to a second signal source for indicating an answered call on the visual indicator;
- a third switch means connected to said control electrode for connecting said control electrode to a third signal source for indicating a call on hold on the visual indicator;
- a fourth switch means connected to said control electrode and to at least one of the first and third signal sources for providing a visual indication of attendant recall at a predetermined time after a call being placed on hold, said visual recall indication being substantially different from the visual indication of ring, answered call, and hold condition.
A line circuit for use with a key telephone system comprising:
- first and second input terminals for connection to first and second telephone conductors;
- a hold impedance;
- a hold switch connected to said hold impedance for connecting said hold impedance across the first and second telephone conductors;
- sensing means connected to said first input terminal for sensing a ringing signal;
- ring switch means connected to said sensing means for energizing a local ringer;
- timing means and means connecting said timing means to said hold switch and said ring switch for turning on said ring switch thus re-ringing the local ringer at a predetermined time after energization of said hold switch.
Dependencies are inferred from the claim text.