Method and system for providing DC power on local telephone lines

• US 8,787,562 B2
• Filed: 12/18/2006
• Issued: 07/22/2014
• Est. Priority Date: 01/30/2003
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Conversant Intellectual Property Management Inc (MOSAID Technologies Inc. (f/k/a Conversant Intellectual Property Management))
• Inventors: Binder, Yehuda, Hazani, Ami, Kofman, Semion
• Primary Examiner(s): Jamal, Alexander
• Application Number:
  US11/640,300
• Publication Number:
  US 20070127715A1
• Time in Patent Office: 2,773 Days
• Field of Search: 379413-41304
• US Class Current: 379/413
• CPC Class Codes: H04M 19/08 with current supply sources at the substations generating ringing current H04M19/04
• CPC Class Codes: H04M 9/08 Two-way loud-speaking telephone systems with means for conditioning the signal, e.g. for suppressing echoes for one or both directions of traffic

Abstract

A telephone unit device connectable in series between a telephone set and a wire pair coupled to a telephone service and carrying DC power and an AC telephone signal. The device includes: a first connector connectable to the wire pair; a second connector connectable to the telephone set; means connected between the first and second connectors for passing substantially without change the AC telephone signal between the wire pair and the telephone set; and means connected between the first and second connectors for receiving DC power only from the wire pair and converting the DC power to a level suitable for proper telephone operation of the telephone set connected thereto.

Claims

1. A telephone unit device connectable in series between an analog telephone set and a wire pair coupled to a telephone service and carrying DC power and an analog telephone signal, said device comprising:

a first connector connectable to the wire pair;

a second connector connectable to the telephone set;

a signal passing circuit connected between said first and second connectors for passing substantially without change the analog telephone signal between the wire pair and the analog telephone set; and

a DC/DC converter connected in series between said first and second connectors for receiving DC power only from the wire pair and converting the DC power to a level suitable for proper telephone operation of the analog telephone set connected thereto

wherein;

said signal passing circuit comprises a transformer composed of a primary winding and a secondary winding and first and second capacitors, each said capacitor being connected in series with a respective one of said windings; and

said DC\DC converter is connected between said first and second capacitors.

2. The device of claim 1 integrated into one of:

an analog telephone set; and

a telephone outlet.

3. An outlet comprising the telephone unit device of claim 1.

4. The device of claim 1 in combination with:

an off-hook detector couplable to the analog telephone set for detecting an off-hook condition of the analog telephone set;

an off-hook transmitter coupled to said off-hook detector and to the wire pair for supplying an off-hook indication to the wire pair in response to detection of an off-hook condition by said off-hook detector.

5. The device of claim 4, wherein the off-hook indication is a signal composed of one or more tones.

6. The device of claim 4, wherein said off-hook indication is provided by a variable impedance that assumes a selected value to produce the off-hook indication.

7. The device of claim 4, wherein the off-hook indication is a message sent over a data communication network.

8. The device of claim 7, wherein the data communication network uses the wire pair as a communication medium.

9. The device of claim 1, wherein:

each of said primary and secondary windings has a center tap; and

each of said first and second capacitors is connected to the center tap of a respective one of said primary and secondary windings.

10. The device of claim 1, wherein the telephone set is connectable to only said second connector.