US3826977A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Test set for tracing and checking the continuity of electrical circuits
Assignee: Individual
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Filing: 1973-05-24
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Granted: 1974-07-30
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Expires: 1993-05-24
Abstract
Abstract Apparatus is disclosed for locating and tracing an electrical path through electrical conductors. A signal generator producing a multi-harmonic signal is connected to an electrical conductor under test. The signal includes amplitude modulated harmonics in the AM broadcast band whereby standard AM radio receivers can be used to detect the conductor transmitting the signal. Selectively energized additional circuitry provides a visual indication of a continuity check performed on the electrical conductor.
Inventors
- 👤 C Woodworth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 18:32
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/50; G01R31/54; G01R31/52; G01R31/58
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
285 words
An electrical circuit test set for tracing an electrical path through an electrical conductor, said set comprising in combination: a. a first circuit for testing the electrical continuity of the electrical conductors, said first circuit including a current limiting resistor in series with a light emitting diode; b. a second circuit for generating a tone, said second circuit including: 1. a voltage divider network for establishing a reference voltage; 2. a current charging network; 3. a first semiconductor having a base electrode, an emitter electrode and a collector electrode, said base electrode of said first semiconductor being connected to said voltage divider network and said emitter electrode of said first semiconductor being connected to said current charging network; 4. a second semiconductor having a base electrode, an emitter electrode and a collector electrode, said base electrode of said second semiconductor being connected to said collector electrode of said first semiconductor, said collector electrode of said second semiconductor being connected to said base electrode of said first semiconductor; 5. a current limiting resistor connected intermediate said emitter electrode of said second semiconductor and ground; c. a d-c power source having a positive terminal and a negative grounded terminal; d. a switch for selectively connecting the positive terminal of said power source to said first or second circuit; and e. a pair of test probes, one of said probes being connected to the negative terminal of said power source and another of said probes being connected in series with each of said first and second circuits; whereby, said pair of probes are common to both said first and second circuits and the selection of said first or second circuit to be employed is controlled by said switch.
Claim 2
Dependent Claim
285 words
An electrical circuit test set for tracing an electrical path through an electrical conductor, said set comprising in combination: a. a first circuit for testing the electrical continuity of the electrical conductors, said first circuit including a current limiting resistor in series with a light emitting diode; b. a second circuit for generating a tone, said second circuit including: 1. a voltage divider network for establishing a reference voltage; 2. a current charging network; 3. a first semiconductor having a base electrode, an emitter electrode and a collector electrode, said base electrode of said first semiconductor being connected to said voltage divider network and said emitter electrode of said first semiconductor being connected to said current charging network; 4. a second semiconductor having a base electrode, an emitter electrode and a collector electrode, said base electrode of said second semiconductor being connected to said collector electrode of said first semiconductor, said collector electrode of said second semiconductor being connected to said base electrode of said first semiconductor; 5. a current limiting resistor connected intermediate said emitter electrode of said second semiconductor and ground; c. a d-c power source having a positive terminal and a negative grounded terminal; d. a switch for selectively connecting the positive terminal of said power source to said first or second circuit; and e. a pair of test probes, one of said probes being connected to the negative terminal of said power source and another of said probes being connected in series with each of said first and second circuits; whereby, said pair of probes are common to both said first and second circuits and the selection of said first or second circuit to be employed is controlled by said switch.
Claim 3
Dependent Claim
20 words
The combination as set forth in claim 1 wherein said first and second semiconductors comprise PNP and NPN transistors, respectively.
Claim 4
Dependent Claim
4 words
a current charging network;
Claim 5
Dependent Claim
4 words
a current charging network;
Claim 6
Dependent Claim
43 words
a first semiconductor having a base electrode, an emitter electrode and a collector electrode, said base electrode of said first semiconductor being connected to said voltage divider network and said emitter electrode of said first semiconductor being connected to said current charging network;
Claim 7
Dependent Claim
43 words
a first semiconductor having a base electrode, an emitter electrode and a collector electrode, said base electrode of said first semiconductor being connected to said voltage divider network and said emitter electrode of said first semiconductor being connected to said current charging network;
Claim 8
Dependent Claim
18 words
The combination as set forth in claim 2 wherein said other probe is grounded through a Zener diode.
Claim 9
Dependent Claim
48 words
a second semiconductor having a base electrode, an emitter electrode and a collector electrode, said base electrode of said second semiconductor being connected to said collector electrode of said first semiconductor, said collector electrode of said second semiconductor being connected to said base electrode of said first semiconductor;
Claim 10
Dependent Claim
48 words
a second semiconductor having a base electrode, an emitter electrode and a collector electrode, said base electrode of said second semiconductor being connected to said collector electrode of said first semiconductor, said collector electrode of said second semiconductor being connected to said base electrode of said first semiconductor;
Claim 11
Dependent Claim
26 words
The combination as set forth in claim 3 including a d-c blocking capacitor disposed intermediate said emitter electrode of said NPN transistor and said other probe.
Claim 12
Dependent Claim
32 words
The combination as set forth in claim 1 including a diode across said resistor and said light emitting diode of said first circuit to prevent reverse bias of said light emitting diode.
Claim 13
Dependent Claim
117 words
a current limiting resistor connected intermediate said emitter electrode of said second semiconductor and ground; c. a d-c power source having a positive terminal and a negative grounded terminal; d. a switch for selectively connecting the positive terminal of said power source to said first or second circuit; and e. a pair of test probes, one of said probes being connected to the negative terminal of said power source and another of said probes being connected in series with each of said first and second circuits; whereby, said pair of probes are common to both said first and second circuits and the selection of said first or second circuit to be employed is controlled by said switch.
Claim 14
Dependent Claim
117 words
a current limiting resistor connected intermediate said emitter electrode of said second semiconductor and ground; c. a d-c power source having a positive terminal and a negative grounded terminal; d. a switch for selectively connecting the positive terminal of said power source to said first or second circuit; and e. a pair of test probes, one of said probes being connected to the negative terminal of said power source and another of said probes being connected in series with each of said first and second circuits; whereby, said pair of probes are common to both said first and second circuits and the selection of said first or second circuit to be employed is controlled by said switch.
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) | 1977-07-29 | 1978-01-28 | 1978-07-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-29 | 1982-01-28 | 1982-07-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-29 | 1986-01-28 | 1986-07-30 | $7700.00 | Window Closed / Lapsed |