Active decoupling and power management circuit for line-powered ringing generator

• US 6,690,792 B1
• Filed: 11/19/1999
• Issued: 02/10/2004
• Est. Priority Date: 11/19/1999
• Status: Expired due to Term

• Current Assignee: ADTRAN Incorporated (ADTRAN Holdings, Inc.)
• Original Assignee: ADTRAN Incorporated (ADTRAN Holdings, Inc.)
• Inventors: Taylor, Jeffrey K., Wilkes, John B. Jr., Robinson, Steven M., McGary, John S.
• Primary Examiner(s): BARNIE, REXFORD N
• Application Number:
  US09/442,299
• Time in Patent Office: 1,544 Days
• Field of Search: 379/399.01, 379/412, 379/413, 379/372, 379/324, 379/322, 379/348, 379/350, 379/382, 379/418, 379/413.01, 379/323
• US Class Current: 379/418
• CPC Class Codes: H04M 3/04 the calling signal being supplied from the final selector

Abstract

A ringing voltage power management circuit is configured to extract an isolated high-value intermediate voltage from a central office powered digital subscriber line through a current limiting circuit, and to charge a storage capacitor that serves as an energy reservoir for the ring generator of a subscriber line circuit. The storage capacitor and the current limiting circuit isolate the peak power drawn by the ringing load from the telephone line and translate the ringing signal'"'"'s (20 Hz) ripple to the sub-Hz oscillations of the ringing cadence.

Claims

1. A method of supplying power to a ring generator for a telecommunication device, comprising the steps of:

(a) coupling said telecommunication device to a telecommunication link that conveys telecommunication signals to and from, and is remotely powered by, a telecommunication facility, wherein instantaneous power supplied from said remotely powered telecommunication link is less than a total power requirement of said telecommunication device and said ring generator during operation of said ring generator;

(b) during intervals other than powering of said ring generator, storing electrical energy from said remotely powered telecommunication link; and

(c) during intervals of powering said ring generator, using electrical energy stored in step (b) to augment power supplied from said telecommunication link and realize said total power requirement for ringing operation of said ring generator and operating said telecommunication device without exceeding maximum power available from said telecommunication link.

2. The method according to claim 1, wherein step (b) comprises storing, from said remotely powered telecommunication link, electrical energy that is effective to provide average power required by said ringing generator during a ringing period.

3. The method according to claim 1, wherein step (b) includes decoupling, from said telecommunication link, low frequency ripple noise associated with said operation of said ring generator, so as not to interfere with digital telecommunication signals being conveyed over said telecommunication link during remote powering thereof.

4. The method according to claim 1, wherein step (b) comprises

(b1) generating an isolated high-value voltage from electrical energy derived from said remotely powered telecommunication link, and

(b2) coupling said isolated high-value voltage generated in step (b1) through a current limiting circuit to an electrical storage device so as to store said electrical energy therein.

5. The method according to claim 4, wherein said ring generator comprises a regulating ring generator to which electrical energy stored in said electrical storage device is coupled in step (c).

6. The method according to claim 4, wherein step (c) comprises controllably coupling electrical energy stored in said electrical storage device to said ring generator by way of a ring generator pre-regulator.

7. The method according to claim 6, wherein said electrical storage device comprises a storage capacitor, and wherein said ring generator pre-regulator is operative to convert a voltage across said capacitor into a ringing rail voltage that is coupled to a subscriber line interface circuit which generates a ringing signal for said telecommunication device.

8. The method according to claim 7, wherein said ring generator pre-regulator includes a pulse width modulator that is operative to control the generation of a voltage for powering said ring generator in accordance with an adjustable duty cycle waveform having a frequency higher than the frequency of said ringing signal.

9. The method according to claim 8, wherein said pulse width modulator is operative to monitor the voltage across said storage capacitor and to adjust the duty cycle of said adjustable duty cycle waveform in accordance therewith, so as to maintain a prescribed voltage to said subscriber line interface circuit.

10. A circuit for powering a ring generator for a telecommunication device using power extracted from a telecommunication link that conveys telecommunication signals and is remotely powered by way of a telecommunication facility, wherein instantaneous power supplied from said remotely powered telecommunication link is less than a total power requirement of said telecommunication device and said ring generator during operation of said ring generator, said circuit comprising

an electrical storage device;

and

an interface circuit coupled in circuit with said telecommunication link and said electrical storage device, and with said electrical storage device and said ring generator, and being operative, during intervals other than powering of said ring generator, to store in said electrical storage device electrical energy derived from said remotely powered telecommunication link and, during intervals of powering said ring generator, to use electrical energy stored in said electrical storage device to augment power supplied from said telecommunication link and realize said total power requirement for ringing operation of said ring generator and operating said telecommunication device without exceeding maximum power available from said telecommunication link.

11. The circuit according to claim 10, wherein said interface circuit is operative to extract from said remotely powered telecommunication link for storage in said electrical storage device, electrical energy that is effective to provide average power required by said ringing generator during a ringing period.

12. The circuit according to claim 10, wherein said interface circuit includes a voltage regulator coupled in circuit with said electrical storage device and said ring generator and being operative to generate said ringing voltage for operating said ring generator.

13. The circuit according to claim 12, wherein said electrical storage device comprises a storage capacitor, and wherein said voltage regulator comprises a ring generator pre-regulator that is operative to convert a voltage across said capacitor into a ringing rail voltage that is coupled to a subscriber line interface circuit which generates a ringing signal for said telecommunication device.

14. The circuit according to claim 13, wherein said ring generator pre-regulator includes a pulse width modulator that is operative to control the generation of a voltage for powering said ring generator in accordance with an adjustable duty cycle waveform having a frequency higher than the frequency of said ringing signal.

15. The circuit according to claim 14, wherein said pulse width modulator is operative to monitor the voltage across said storage capacitor and to adjust the duty cycle of said adjustable duty cycle waveform in accordance therewith, so as to maintain a prescribed voltage to said subscriber line interface circuit.

16. The circuit according to claim 12, wherein said interface circuit is configured to generate an isolated high-value voltage from electrical energy derived from said remotely powered telecommunication link, and includes a current limiting circuit through which said isolated high-value voltage is coupled to said electrical storage device.

17. The circuit according to claim 12, wherein said interface circuit is configured to decouple low frequency ripple noise associated with operation of said ring generator from said telecommunication link, so as not to interfere with digital telecommunication signals being conveyed over said telecommunication link during remote powering thereof.

18. The circuit according to claim 12, wherein said ring generator comprises a regulating ring generator.

19. A remote terminal circuit for powering a ring generator for a telecommunication device using power extracted from a telecommunication link that conveys telecommunication signals and is remotely powered by way of a telecommunication facility, wherein instantaneous power supplied from said remotely powered telecommunication link is less than a total power requirement of said telecommunication device and said ring generator during operation of said ring generator, said circuit comprising an electrical storage device, and an interface circuit coupled in circuit with said telecommunication link and said electrical storage device, and in circuit with said electrical storage device and said ring generator, and being operative, during intervals other than powering of said ring generator, to store in said electrical storage device electrical energy derived from said remotely powered telecommunication link and, during intervals of powering said ring generator, to use electrical energy stored in said electrical storage device to augment power supplied from said telecommunication link and realize said total power requirement for ringing operation of said ring generator and operating said telecommunication device without exceeding maximum power available from said telecommunication link, while decoupling low frequency ripple noise associated with operation of said ring generator from said telecommunication link, so as not to interfere with digital telecommunication signals conveyed over said remotely powered telecommunication link.

20. The remote terminal circuit according to claim 19, wherein said interface circuit is configured to generate an isolated high-value voltage from electrical energy derived from said remotely powered telecommunication link, and includes a current limiting circuit through which said isolated high-value voltage is coupled to said electrical storage device.