US3976849A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Telephone wiring tester
Assignee: TELZON Inc 14408 NE 20TH STREET BELLEVUE WASHINGTON 98007 A CORP OF WASHINGTON
•
Filing: 1975-08-01
•
Granted: 1976-08-24
•
Expires: 1995-08-01
Abstract
Abstract A test unit for testing the wiring connections in modular telephone installations. The unit consists of a housing with an input jack to receive the standard plug used to connect the telephone wiring to a handset. The jack has four terminals, one pair corresponding to the green and red(tip-ring) line wires, and the other pair corresponding to the yellow and black (ground and lamp a.c.) line wires. The tip-ring terminals are connected in the housing through a first diode, a Zener diode and a resistor to a "tip-ring" L.E.D. The a.c. terminals are connected in the housing to a "lamp" L.E.D. through a diode and a transistor, controlled by a network including a blocking capacitor. When the telephone line plug is inserted in the test unit jack, the "tip-ring" L.E.D. will light only if the "tip-ring" line voltage is correct in magnitude and polarity, and the tip ring line conductors have not been interchanged with the a.c. line conductors. The "lamp" L.E.D. will light to indicate proper a.c. voltage on the a.c. line conductors. If the a.c. voltage is too low the "lamp" L.E.D. will be dim. The "lamp" L.E.D. will not light if the a.c. line conductors carry d.c. voltage.
Inventors
- 👤 Louis W. Champan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 23:06
CPC Classifications
H; H04; H04M; H04M3/00; H04M3/22; H04M3/26; H04M3/28; H04M3/30; H04M1/00; H04M1/24
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
158 words
In combination with a four-terminal plug for connection of a telephone handset employing d.c. tip-ring voltage and a.c. lamp voltage coupled over d.c. and a.c. lines respectively, a telephone line testing device for assuring proper connections of said voltages to said lines comprising a support provided with a four-contact jack adapted to receive the four-terminal handset plug connected to said d.c. and a.c. lines, said jack having two d.c. contacts and two a.c. contacts, a series circuit branch on said support including a first rectifier and a first electrical light-emitting device, circuit means connecting said series circuit branch to the two d.c. contacts, a second circuit branch on said support comprising an a.c. amplifier including a d.c.-blocking input capacitor, a second electrical light-emitting device connected to the output of the amplifier, and a second rectifier connected in series with the input of the amplifier, and circuit means connecting said second circuit branch to the two a.c. jack contacts.
Claim 2
Dependent Claim
158 words
In combination with a four-terminal plug for connection of a telephone handset employing d.c. tip-ring voltage and a.c. lamp voltage coupled over d.c. and a.c. lines respectively, a telephone line testing device for assuring proper connections of said voltages to said lines comprising a support provided with a four-contact jack adapted to receive the four-terminal handset plug connected to said d.c. and a.c. lines, said jack having two d.c. contacts and two a.c. contacts, a series circuit branch on said support including a first rectifier and a first electrical light-emitting device, circuit means connecting said series circuit branch to the two d.c. contacts, a second circuit branch on said support comprising an a.c. amplifier including a d.c.-blocking input capacitor, a second electrical light-emitting device connected to the output of the amplifier, and a second rectifier connected in series with the input of the amplifier, and circuit means connecting said second circuit branch to the two a.c. jack contacts.
Claim 3
Dependent Claim
18 words
The telephone line testing device of claim 1, and a zener diode connected in said series circuit branch.
Claim 4
Dependent Claim
21 words
The telephone line testing device of claim 2, and wherein said zener diode has a conduction voltage of approximately 15 volts.
Claim 5
Dependent Claim
25 words
The telephone line testing device of claim 2, and wherein said zener diode is connected between said first rectifier and said first electrical light-emitting device.
Claim 6
Dependent Claim
166 words
A telephone line testing device comprising a support provided with a four-contact jack adapted to receive a four-terminal handset plug connected to the telephone lines, said jack having two d.c. contacts and two a.c. contacts, a series circuit branch on said support including a first rectifier and a first electrical light-emitting device, circuit means connecting said series circuit branch to the two d.c. contacts, a second circuit branch on said support comprising an a.c. amplifier including a d.c.-blocking input capacitor, a second electrical light-emitting device connected to the output of the amplifier, and a second rectifier connected in series with the input of the amplifier, and circuit means connecting said second circuit branch to the two a.c. jack contacts, and wherein said amplifier comprises a transistor, the output of said second rectifier being connected through said blocking capacitor to the base of the transistor and to the collector of the transistor, the second electrical light emitting device being connected in the emitter circuit of the transistor.
Claim 7
Dependent Claim
166 words
A telephone line testing device comprising a support provided with a four-contact jack adapted to receive a four-terminal handset plug connected to the telephone lines, said jack having two d.c. contacts and two a.c. contacts, a series circuit branch on said support including a first rectifier and a first electrical light-emitting device, circuit means connecting said series circuit branch to the two d.c. contacts, a second circuit branch on said support comprising an a.c. amplifier including a d.c.-blocking input capacitor, a second electrical light-emitting device connected to the output of the amplifier, and a second rectifier connected in series with the input of the amplifier, and circuit means connecting said second circuit branch to the two a.c. jack contacts, and wherein said amplifier comprises a transistor, the output of said second rectifier being connected through said blocking capacitor to the base of the transistor and to the collector of the transistor, the second electrical light emitting device being connected in the emitter circuit of the transistor.
Claim 8
Dependent Claim
28 words
The telephone line testing device of claim 5, and wherein said series branch includes a zener diode connected between said first rectifier and said first electrical light-emitting device.
Claim 9
Dependent Claim
21 words
The telephone line testing device of claim 6, and wherein said zener diode has a conduction voltage of approximately 15 volts.
Claim 10
Dependent Claim
17 words
The telephone line testing device of claim 7, and wherein said electrical light-emitting devices comprise light-emitting diodes.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-08-24 | 1980-02-23 | 1980-08-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-08-24 | 1984-02-23 | 1984-08-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-08-24 | 1988-02-23 | 1988-08-24 | $7700.00 | Window Closed / Lapsed |