US4600810A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Telephone line tester
Assignee: TE Connectivity Corp
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Filing: 1984-09-07
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Granted: 1986-07-15
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Expires: 2004-09-07
Abstract
Abstract A telephone line tester is a self-contained unit which, when plugged into a premise wiring telephone jack, determines whether or not a signal of adequate power is being received. If a satisfactory signal is received, the tester will give a visual indication thereby denoting the operating condition of the telephone normally connected to the jack.
Inventors
- 👤 Steven Feldman
- 👤 David J. Kimmel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 13:36
CPC Classifications
H; H04; H04M; H04M3/00; H04M3/22; H04M3/26; H04M3/28; H04M3/30; H04M1/00; H04M1/24
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
116 words
A hand-held testing device for testing telephone tip and ring signal voltages comprising: a body portion, a test circuit attached to the body portion, the test circuit comprising voltage rectifer means for compensating polarity mismatches of the tip and ring signals as an input voltage, reference voltage means for establishing and holding constant a predetermined voltage, voltage divider means, voltage comparator means for comparing the reference voltage and the voltage across the voltage divider, and sensory means for indicating conditions where the tip and ring signal voltage exceeds the reference voltage, whereby the circuit may be connected to the telephone tip and ring signal thereby isolating faulty electronics in a telephone set or local premises wiring.
Claim 2
Dependent Claim
116 words
A hand-held testing device for testing telephone tip and ring signal voltages comprising: a body portion, a test circuit attached to the body portion, the test circuit comprising voltage rectifer means for compensating polarity mismatches of the tip and ring signals as an input voltage, reference voltage means for establishing and holding constant a predetermined voltage, voltage divider means, voltage comparator means for comparing the reference voltage and the voltage across the voltage divider, and sensory means for indicating conditions where the tip and ring signal voltage exceeds the reference voltage, whereby the circuit may be connected to the telephone tip and ring signal thereby isolating faulty electronics in a telephone set or local premises wiring.
Claim 3
Dependent Claim
23 words
The device of claim 1 further comprising interconnection means for connecting the circuit to the tip and ring signal of the telephone wiring.
Claim 4
Dependent Claim
20 words
The device of claim 2 wherein the interconnection means comprises a modular plug for receipt into a telephone modular jack.
Claim 5
Dependent Claim
24 words
The device of claim 1 wherein the voltage rectifier means, the reference voltage means, and the voltage divider means are in parallel circuit configuration.
Claim 6
Dependent Claim
16 words
The device of claim 4 wherein the voltage rectifier means comprises a full wave bridge rectifier.
Claim 7
Dependent Claim
13 words
The device of claim 5 wherein the bridge is formed by four diodes.
Claim 8
Dependent Claim
20 words
The device of claim 4 wherein the reference voltage means comprises a load resistor in series with a zener diode.
Claim 9
Dependent Claim
16 words
The device of claim 7 wherein the voltage divider means comprises two load resistors in series.
Claim 10
Dependent Claim
27 words
The device of claim 8 wherein the positive input of the voltage comparator is taken between the load resistor and zener diode of the voltage reference means.
Claim 11
Dependent Claim
23 words
The device of claim 9 wherein the negative input of the voltage comparator is taken between the load resistors of the voltage divider.
Claim 12
Dependent Claim
17 words
The device of claim 10 wherein the voltage comparator has switching means to direct the current path.
Claim 13
Dependent Claim
36 words
The device of claim 11 wherein the switching means shunts the current path to ground when the voltage at the negative input to the voltage comparator is less than the reference voltage at the positive input.
Claim 14
Dependent Claim
37 words
The device of claim 11 wherein the switching means diverts the current path through the sensory means when the voltage at the negative input to the voltage comparator exceeds that of the voltage at the positive input.
Claim 15
Dependent Claim
14 words
The device of claim 1 wherein the sensory means is a light emitting diode.
Claim 16
Dependent Claim
33 words
The device according to claim 1 wherein said test circuit further comprises: latching means whereby ambiguous current approaching a threshold between pass and fail conditions will not cause an output oscillation between states.
Claim 17
Dependent Claim
37 words
The device according to claim 1 wherein said test circuit further comprises: unlatching means having a hysteresis such that a test current must fall below a threshold before a fail condition is indicated to prevent output oscillation.
Claim 18
Dependent Claim
29 words
The device according to claim 1 wherein said test circuit further comprises: both latching and unlatching means whereby output oscillation caused by switching at close-to-acceptable levels will be prohibited.
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) | 1989-07-14 | 1990-01-13 | 1990-07-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-07-14 | 1994-01-13 | 1994-07-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-07-14 | 1998-01-13 | 1998-07-15 | $7700.00 | Window Closed / Lapsed |