US4878025A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Trouble finder for testing an electrical system of a vehicle for short-circuiting
Assignee: Individual
•
Filing: 1987-02-09
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Granted: 1989-10-31
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Expires: 2007-02-09
Abstract
Abstract A device for tracing preferably short-circuiting in electric systems. When tracing short-circuiting it is desirable that voltage and current will have normal values immediately after elimination thereof, for instance by contact. This object has been achieved in that an oscillator (23) limits the current at the output (19) to near 0 A as long as short-circuiting remains. When the short-circuiting ceases this is detected by a unit of sensitivity (24) and, as a result of this, the oscillation stops and preset current and voltage levels are entered immediately and automatically.
Inventors
- 👤 Peter Persson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:37
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/005; G01R31/006; B; B60; B60Q; B60Q11/00; G01R31/50; G01R31/52
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
208 words
A trouble finder for testing an electrical system, comprising: a transformer having an input adapted to be coupled to a power source; a rectifier, coupled to an output of said transformer; an oscillator unit coupled so as to receive power from said rectifier; a regulator coupled to said rectifier so as to receive power therefrom; means for coupling an output of said oscillator to an input of said regulator; first and second output terminals for connection to said electrical system to be tested; an ammeter coupling said voltage regulator to said first output terminal; a voltmeter coupling said first and second output terminals; a protection unit coupled to said regulator; a sensitivity unit, connected to said first and second output terminals and arranged to enable sensing of a voltage across said output terminals, the output voltage deviating from zero upon connection of said trouble finder to an electrical system being tested; a potentiometer, coupled to said sensitivity unit, for balancing the sensed voltage to zero level; and wherein said oscillator unit is intended for limiting the output current of the regulator unit at an occurrence of a short-circuit in the electrical system, said oscillator unit being activated by a balanced 0-zero voltage level detected by the sensitivity unit.
Claim 2
Dependent Claim
208 words
A trouble finder for testing an electrical system, comprising: a transformer having an input adapted to be coupled to a power source; a rectifier, coupled to an output of said transformer; an oscillator unit coupled so as to receive power from said rectifier; a regulator coupled to said rectifier so as to receive power therefrom; means for coupling an output of said oscillator to an input of said regulator; first and second output terminals for connection to said electrical system to be tested; an ammeter coupling said voltage regulator to said first output terminal; a voltmeter coupling said first and second output terminals; a protection unit coupled to said regulator; a sensitivity unit, connected to said first and second output terminals and arranged to enable sensing of a voltage across said output terminals, the output voltage deviating from zero upon connection of said trouble finder to an electrical system being tested; a potentiometer, coupled to said sensitivity unit, for balancing the sensed voltage to zero level; and wherein said oscillator unit is intended for limiting the output current of the regulator unit at an occurrence of a short-circuit in the electrical system, said oscillator unit being activated by a balanced 0-zero voltage level detected by the sensitivity unit.
Claim 3
Dependent Claim
32 words
A trouble finder according to claim 1, wherein said means for coupling an output of said oscillator to said regulator comprises a manually operable switch coupled between said oscillator and said regulator.
Claim 4
Dependent Claim
31 words
A trouble finder according to claim 2 wherein further comprising means, coupled to said protection unit for protecting against overheating, said protecting means being activated by a resistance sensitive to temperature.
Claim 5
Dependent Claim
37 words
A trouble finder according to claim 3 further comprising a first light-emitting diode connected to said sensitivity unit so as to be activated when a voltage deviating from 0 appears across said first and second output terminals.
Claim 6
Dependent Claim
22 words
A trouble finder according to claim 4 further comprising a second light-emitting diode connected said protection unit for indicating an overheating condition.
Claim 7
Dependent Claim
22 words
A trouble finder according to claim 3 further comprising a second light-emitting diode connected said protection unit for indicating an overheating condition.
Claim 8
Dependent Claim
37 words
A trouble finder according to claim 2 further comprising a first light-emitting diode connected to said sensitivity unit so as to be activated when a voltage deviating from 0 appears across said first and second output terminals.
Claim 9
Dependent Claim
22 words
A trouble finder according to claim 7 further comprising a second light-emitting diode connected said protection unit for indicating an overheating condition.
Claim 10
Dependent Claim
22 words
A trouble finder according to claim 2 further comprising a second light-emitting diode connecting said protection unit for indicating an overheating condition.
Claim 11
Dependent Claim
37 words
A trouble finder according to claim 1 further comprising a first light-emitting diode connected to said sensitivity unit so as to be activated when a voltage deviating from 0 appears across said first and second output terminals.
Claim 12
Dependent Claim
22 words
A trouble finder according to claim 10 further comprising a second light-emitting diode connected said protection unit for indicating an overheating condition.
Claim 13
Dependent Claim
22 words
A trouble finder according to claim 1 further comprising a second light-emitting diode connected said protection unit for indicating an overheating condition.
References Cited (Backward Citations)
US4187504A
Cited
US4243934A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-10-30 | 1993-05-01 | 1993-10-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-10-30 | 1997-05-01 | 1997-10-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-10-30 | 2001-05-01 | 2001-10-31 | $7700.00 | Window Closed / Lapsed |