Telephony distribution system

• US 20060029210A1
• Filed: 07/19/2005
• Published: 02/09/2006
• Est. Priority Date: 07/19/2004
• Status: Active Grant

• Current Assignee: Legrand France SA (Legrand SA)
• Original Assignee: Legrand France SA (Legrand SA)
• Inventors: Feugere, Pierre
• Granted Patent: US 7,920,695 B2
• Time in Patent Office: Days
• US Class Current: 379/383
• CPC Class Codes: H04M 3/005 Interface circuits for subscriber lines current supply H04M19/00 and subgroups; supervisory, monitoring or testing arrangements H04M3/22 and subgroups; in key telephone systems H04M9/006
• CPC Class Codes: H04M 3/12 Marking faulty circuits "busy"; Enabling equipment to disengage itself from faulty circuits ; Using redundant circuits; Response of a circuit, apparatus or system to an error
• CPC Class Codes: H04M 3/18 with means for reducing interference or noise; with means for reducing effects due to line faults with means for protecting lines
• CPC Class Codes: H04Q 11/0421 Circuit arrangements therefor
• CPC Class Codes: H04Q 2213/13003 Constructional details of switching devices
• CPC Class Codes: H04Q 2213/13076 Distributing frame, MDF, cross-connect switch
• CPC Class Codes: H04Q 2213/1308 Power supply
• CPC Class Codes: H04Q 2213/13162 Fault indication and localisation
• CPC Class Codes: H04Q 2213/13166 Fault prevention
• CPC Class Codes: H04Q 2213/13305 Transistors, semiconductors in general
• CPC Class Codes: H04Q 2213/1332 Logic circuits
• CPC Class Codes: H04Q 2213/13389 LAN, internet

Abstract

A telephony distribution system includes a plurality of terminals with two connection points (16A), each for one pair of conductors (17A) forming part of a telephony distribution installation, and, for each of those terminals (16A), a short-circuit manager (25) including a substitution current source (26), a switch (27) and control means (28-31) for causing the switch (27) normally to assume a position in which its output terminal (34) is connected to an input terminal (32) itself connected to a pair of conductors (13, 15) providing a telephone line and to cause the switch (27). In the event of a short-circuit between the two connection points of the terminal (16A) concerned, to assume a second position in which that terminal is connected to the auxiliary current source (26).

Claims

1. Telephony distribution system comprising at least one first terminal (12;

14) with two connection points for a pair of conductors (13;

15) providing a telephone line and a plurality of second terminals with two connection points (16A-16H) for a pair of conductors (17A-17H) forming part of a telephony distribution installation, with each connection point of each of said second terminals (16A-16H) connected or connectable to a respective connection point of said first terminal (12;

14), which system is characterized in that it comprises, for each of said second terminals (16A-16H), a short circuit manager (25) including;

a substitution current source (26);

a switch (27) having a first input terminal (32) Connected or connectable to said first terminal (12;

14), a second input terminal (33) connected to said substitution current source (26), and an output terminal (34) connected to this second terminal (16A-16H), without being connected to another second terminal (16A-16H), said switch (27) assuming a first position in which it connects the output terminal (34) to the first input terminal (32) and isolates the output terminal (34) and the second input terminal (33) from each other and a second position in which it connects the output terminal (34) and the second input terminal (33) to each other and isolates the output terminal (34) and the first input terminal (32) from each other; and

Control means (28-31) for controlling said switch (27) to cause it normally to assume said first position and to cause it to assume said second position in the event of a short-circuit between the two connection points of this second terminal (16A-16H).

2. System according to claim 1, characterized in that said control means (28-31) are adapted to detect if a first predetermined current and/or voltage condition representative of an absence of a short-circuit between the two connection points of the second terminal (16A-16H) concerned is satisfied or not, adapted to detect if a second predetermined current and/or voltage condition representative of a short-circuit between the two connection points of that second terminal (16A-16H) is satisfied or not, said second condition being other than the opposite of said first condition, and adapted to cause said switch (27) to assume said first position if said first condition is satisfied, to cause said switch (27) to assume said second position if said second condition is satisfied, and otherwise to cause said switch (27) to remain in said first position or in said second position.

3. System according to claim 2, characterized in that said first condition is the absence of current consumption at the second terminal (16A-16H) concerned and said second condition is the combined presence of consumption of current and presence of an under voltage at the second terminal (16A-16H) concerned.

4. System according to claim 3, characterized in that said control means (28-31) include an under voltage detector (28) for determining if the voltage at the second terminal (16A-16H) concerned is below a predetermined threshold or not, a unit (29) for detecting consumption of current to determine if the current at the second terminal (16A-16H) concerned is above a predetermined threshold or not, a logic unit (30) connected to said under voltage detector (28) and to said current consumption detector circuit (29), and a control unit (31) of said switch (27), said logic unit (30) being adapted to cause said control unit (31) to cause said switch (27) to assume said first position if said current consumption detector (29) does not detect a current consumption higher than said predetermined current threshold at the second terminal (16A-16H) concerned, to cause said switch (27) to assume said second position if said under voltage detector (28) determines that the voltage at the second terminal (16A-16H) concerned is below said predetermined threshold and that said current consumption detector (29) determines at the same time that the current consumption at said second terminal (16A-16H) concerned is above said predetermined current threshold and to cause said switch to remain in said first position or in said second position if said under voltage detector (28) determines that the voltage at said second terminal (16A-16H) concerned is above said predetermined voltage threshold and that the current consumption detector (29) determines that the current at said second terminal (16A-16H) concerned is above said predetermined current threshold.

5. System according to claim 4, characterized in that said predetermined current threshold is from 0.1 to 1.5 mA.

6. System according to claim 4, characterized in that said predetermined voltage threshold is from 2 to 10 V.

7. System according to claim 1, characterized in that said control means include an under voltage detector (28) including a comparator (61) for determining if the voltage at said second terminal (16A-16H) concerned is below a predetermined voltage threshold or not.

8. System according to claim 7, characterized in that said under voltage detector (28) includes a full-wave rectifier diode bridge (50) whose input connection points (51, 52) are connected to input connection points (36, 37) of said under voltage detector (28).

9. System according to claim 1, characterized in that said control means (28-31) include an under voltage detector (28) whose input connection points (36, 37) are connected in parallel with said first input terminal (32) of said switch (27).

10. System according to claim 1, characterized in that said control means (28-31) include a current consumption detector including an optocoupler (47) for detecting if the current at said second terminal (16A-16H) concerned is above a predetermined threshold or not.

11. System according to claim 10, Characterized in that said optocoupler (47) is provided with a set (48) of two photodiodes disposed in antiparallel.

12. System according to claim 1, characterized in that said control means (28-31) include a current consumption detector (29) two input connection points (39, 40) of which are disposed in series between one of the connection points of said output terminal (34) of the switch (27) and one of the connection points of the second terminal (16A-16H) concerned.

13. System according to claim 1, characterized in that said control means (28-31) include a logic unit (30) including a bistable (75).

14. System according to claim 1, characterized in that said control means (28-31) include a control unit (31) including a solenoid (80) and a direct current source having a ground pole (55) and a positive pole (56) with each connection point (81, 82) of said solenoid connected to each pole (55, 56) of said direct current source via a transistor (84, 86, 88, 90) whereof a control electrode is connected to a connection point (45) of said control unit (31) via a bias resistor (91, 92) or via a logic signal inverter (95) an via a bias resistor (93, 94), so that when said connection point (45) is at the same potential as said ground pole (55), a first (84) of said transistors, disposed between said positive pole (56) and a first connection point (81) of said solenoid (80), is turned on whereas a second (90) of said transistors, disposed between a second (82) of said connection points of the solenoid (80) and said ground pole (55), is turned on and the other two transistors (86, 88) are turned off, and so that when said connection point (45) of the control unit (31) is at the same potential as said positive pole (56), a third (88) of said transistors, situated between said positive pole (56) and said second connection point (82) of said solenoid (80), is turned on and the fourth transistor (86), disposed between the first connection pint (81) if said solenoid (80) and said ground pole (55), is turned on and the first transistor (84) and the second transistor (90) are turned off.

15. System according to claim 1, characterized in that said auxiliary current source (26) has two power supply poles and a current limiter resistor (35) disposed between one of said power supply poles and one of the connection points of said second input terminal (33).

16. System according to claim 1, characterized in that it includes two of said first terminals (12, 14) and, for each of said second terminals (16A-16H), a switch (19) having a first input terminal (22) connected to one of said first terminals (12), a second input terminal (23) connected to the other of said first terminals (14) and an output terminal (24) connected to said second terminal (16A-16H) concerned via said short-circuit manager (25), wherein said switch (19) assumes a first position in which it connects the output terminal (24) to the first input terminal (22) and it isolates the output terminal (24) and the second input terminal (23) from each other and assumes a second position in which it connects the output terminal (24) and the second input terminal (23) to each other and it isolates the output terminal (24) and the first input terminal (22) from each other.