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US 4,656,659 AGranted
Programmable ring signal generator
AssigneeITT Corporation
InventorRamon C. W. Chea, Jr.
Life of this patent
Estimating the term…
Abstract
A digitally controlled ring signal generator includes a plurality of ring signal generating sources providing a plurality of inputs to each of a plurality of ring circuits. Each input is an a.c. signal superimposed on a d.c. bias that is greater than or equal to the peak voltage of the a.c. signal.
Claims9
A digitally controlled ring signal generator, comprising:
- means for generating a ring signal including a d.c. to d.c. flyback converter for selectively amplifying one of a plurality of low level ringing signals, each of said plurality of ringing signals having a unique frequency whereby immediate ringing is available to one or more subscriber lines;
- means for sensing a loop current connected directly to said d.c. to d.c. flyback converter;
- means, responsive to said sensed loop current, for generating ringing supervisory signals;
- means, responsive to said generating ringing supervisory signals and an external data input, for providing an output control signal;
- and
- a ring signal reference source, said ring signal reference source being responsive to said output control signal, for coupling said ringing signals to said ring signal generating means whereby the characteristics of said ringing signals are selectable in accordance with said external data input and the presence or absence of said generated ringing signals being determined by said ringing supervisory signals, said ring signal reference source having a d.c. voltage source and a sinusoidal voltage source, said d.c. voltage source having a fixed voltage potential, said fixed voltage potential being greater than or equal to the peak amplitude of said sinusoid.
3 more elements
A digitally controlled ring signal generator, comprising:
- a ring signal reference source for generating a plurality of ringing signals each having a unique frequency and provided as a d.c. biased sinusoidal voltage wherein the d.c. bias potential is greater than or equal to the peak amplitude of said sinusoidal voltage;
- means responsive to a digital control signal for selecting one of said ringing signals;
- means responsive to the selected ringing signal for generating a ring signal, said ring signal generating means including a d.c. to d.c. flyback converter for amplifying said d.c. biased sinusoidal ringing signal from a low amplitude to a high amplitude without distorting the sinusoidal characteristic;
- and
- means for coupling said high amplitude sinusoidal ringing signal directly to a ring signal bus, whereby the sinusoidal ringing signal from the ring signal reference source is biased to a selected polarity so that it may pass through the d.c. to d.c. flyback converter without the usual distortion created by a polarity reversal and the amplified signal can be provided directly to the ring signal bus.
2 more elements
A method of providing a ring signal, comprising the steps of:
- generating a sinusoidal ring signal of selected frequency;
- biasing said sinusoidal ring signal with a selected polarity d.c. voltage so that the sinusoidal signal does not reverse polarity;
- amplifying said d.c. biased sinusoidal ring signal using a d.c. to d.c. flyback converter;
- and
- providing said amplified d.c. biased sinusoidal ring signal directly to a ring signal bus.
2 more elements
Dependencies are inferred from the claim text.