Patent US3694749A successfully refreshed from Google Patents.
US3694749A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ac line voltage drop indicator plug
Assignee: Individual
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Filing: 1970-11-25
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Granted: 1972-09-26
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Expires: 1990-11-25
Abstract
Abstract An AC line voltage-drop indicator plug comprises a small hollow body, from the rear of which project the plug prongs for insertion into a wall outlet. Within the body is contained an electrical circuit consisting of a silicon rectifier and a neon lamp blinker circuit having a variable resistor with a rotatable terminal. The front face of the body has a transparent portion through which the blinking of the neon lamp may be observed, and a rotatable shaft projecting through this face, which is connected to the variable resistor for varying the voltage. To the outer end of the shaft is connected an indicator knob intended to designate, on a scale on the front face, the minimum voltage at which the lamp begins to blink, which is calibrated to be the true voltage in the line.
Inventors
- 👤 Joseph Woroble
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:09
CPC Classifications
G; G01; G01R; G01R19/00; G01R19/165; G01R19/16533; G01R19/16561
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
291 words
An AC line voltage-drop indicator plug, comprising: a small hollow body made of insulating material and having a rear plate and a front plate, said front plate having a window, a pair of spaced plug prongs extending from within said rear plate, through said latter plate and projecting outwardly sufficiently to enable plugging thereof into an electrical line outlet receptacle, an electrical circuit disposed within said body and connected across said prongs, and incorporating: a voltage rectifier connected at one terminal to the rear of one prong, a first fixed resistance connected at one end to the other terminal of said rectifier, a variable resistance having a rotatable terminal and a fixed terminal, the latter being connected to the other end of said first resistance, a second fixed resistance having one end connected to the rotatable terminal of the variable resistance, a third resistance having its one end connected to the rear of the other prong, and its other end connected to the other end of the second fixed resistance, a neon lamp disposed in viewable relation with said window and having one terminal connected to the other terminal of said rectifier, and its other terminal connected between the second and third fixed resistances, and a capacitor connected across the terminals of said lamp, a rotatable shaft connected at one end to the rotatable terminal of said variable resistor for varying the DC voltage passing through said circuit, and having an end projecting outwardly through said front plate, an indicator knob attached to the other end of said shaft, and a scale disposed on the outer surface of said first plate around said shaft and designed to indicate the minimum voltage at an indicator position when said lamp begins to blink.
Claim 2
Dependent Claim
291 words
An AC line voltage-drop indicator plug, comprising: a small hollow body made of insulating material and having a rear plate and a front plate, said front plate having a window, a pair of spaced plug prongs extending from within said rear plate, through said latter plate and projecting outwardly sufficiently to enable plugging thereof into an electrical line outlet receptacle, an electrical circuit disposed within said body and connected across said prongs, and incorporating: a voltage rectifier connected at one terminal to the rear of one prong, a first fixed resistance connected at one end to the other terminal of said rectifier, a variable resistance having a rotatable terminal and a fixed terminal, the latter being connected to the other end of said first resistance, a second fixed resistance having one end connected to the rotatable terminal of the variable resistance, a third resistance having its one end connected to the rear of the other prong, and its other end connected to the other end of the second fixed resistance, a neon lamp disposed in viewable relation with said window and having one terminal connected to the other terminal of said rectifier, and its other terminal connected between the second and third fixed resistances, and a capacitor connected across the terminals of said lamp, a rotatable shaft connected at one end to the rotatable terminal of said variable resistor for varying the DC voltage passing through said circuit, and having an end projecting outwardly through said front plate, an indicator knob attached to the other end of said shaft, and a scale disposed on the outer surface of said first plate around said shaft and designed to indicate the minimum voltage at an indicator position when said lamp begins to blink.
Claim 3
Dependent Claim
146 words
An AC line voltage drop indicator plug, according to claim 1, wherein the electrical circuit comprises: a first fixed resistance having one end connected to the rear of a first prong, a variable resistance having a fixed end connected to the other end of said first resistance, and having a movable terminal, a second fixed resistance having one end connected to the movable terminal of said variable resistance, a rectifier having its first terminal connected to the other end of said second resistance, a third fixed resistance having one end connected to the rear of the other prong and its other end connected to the other terminal of said rectifier, a neon lamp having one terminal connected to the rear of said first prong, and its other terminal connected to said first terminal of said rectifier, and a capacitor connected across the terminals of said lamp.
Claim 4
Dependent Claim
28 words
An AC line voltage drop indicator plug, according to claim 1, in which a fixed resistance is inserted between the rear of the first-named prong and the rectifier.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-09-26 | 1976-03-27 | 1976-09-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-26 | 1980-03-27 | 1980-09-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-26 | 1984-03-27 | 1984-09-26 | $7700.00 | Window Closed / Lapsed |