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US4023101A Expired / Lapsed US ⏱️ 0.0 years remaining

Multiple function electrical measuring and indicating apparatus

Assignee: Individual
•
Filing: 1975-08-20
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Granted: 1977-05-10
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Expires: 1995-08-20
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Abstract

Abstract For measuring and indicating phase voltage, phase sequence and other electrical values in a three-phase power system, and electrical values in single-phase and DC systems, a unitary instrument or apparatus includes a meter movement and three phase-resistors of equal value which are connected to a common juncture defining a neutral point, with a first phase-resistor connected in series with the meter. The three phases of the external circuit to be tested are connected respectively to the three phase-resistors through a three-pole three-position selector switch for selecting the three different phase to "phase-resistor" relationships. A switch connected between a third phase-resistor and the common juncture performs the alternative functions of opening or closing this circuit. A phase-component of different impedance, resistance or reactance value than the phase-resistors is connected through a switch to the common juncture for connecting this phase-resistor to said common juncture in lieu of the third phase-resistor. Phase voltage can be measured when the three phase-resistors are connected to the common juncture; and phase sequence can be indicated when the phase-component is connected in the circuit for one phase in place of a phase-resistor. An amperage measuring circuit is connected to the meter. A third selector switch separates the voltage measuring and amperage measuring functions; and selects shunt resistors for connection across the meter for different voltage or amperage ranges.

Inventors

  • 👤 Virgil F. Christoffer

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 19:18
CPC Classifications
G; G01; G01R; G01R15/00; G01R15/12; G01R15/002; G01R15/08; G01R29/00; G01R29/18

Claims Analysis

Total Claims: 11
Claim 1
Independent Claim 143 words
In apparatus for measuring electrical values of a circuit to be tested a meter for indicating the flow of alternating current, and associated apparatus circuitry comprising three phase-resistors; three phase-conductors for connecting the three phases of an external circuit to the measuring apparatus circuit; a selector switch for connecting said three phase-conductors to said phase-resistors, and for selecting each of three connective relationships between said three phase-conductors and said three phase-resistors; means connecting said three phase-resistors to a common juncture; said meter being connected in series with a first one of said phase-resistors; switch means for selectively connecting and disconnecting a third one of said phase-resistors to and from said common juncture; a phase-component connected with said third phase-resistor to a common terminal of said selector switch; and switch means for selectively connecting and disconnecting said phase-component to and from said common juncture.
Claim 2
Dependent Claim 143 words
In apparatus for measuring electrical values of a circuit to be tested a meter for indicating the flow of alternating current, and associated apparatus circuitry comprising three phase-resistors; three phase-conductors for connecting the three phases of an external circuit to the measuring apparatus circuit; a selector switch for connecting said three phase-conductors to said phase-resistors, and for selecting each of three connective relationships between said three phase-conductors and said three phase-resistors; means connecting said three phase-resistors to a common juncture; said meter being connected in series with a first one of said phase-resistors; switch means for selectively connecting and disconnecting a third one of said phase-resistors to and from said common juncture; a phase-component connected with said third phase-resistor to a common terminal of said selector switch; and switch means for selectively connecting and disconnecting said phase-component to and from said common juncture.
Claim 3
Dependent Claim 51 words
Apparatus as set forth in claim 1 said three phase-resistors and said common juncture defining a basic wye circuit, with said three phase-resistors having equal impedance values; and said phase-component being alternatively connected in said basic wye circuit, with said phase-component having an impedance value different from that of a phase-resistor.
Claim 4
Dependent Claim 20 words
Apparatus as set forth in claim 1 a second selector switch for alternatively connecting selected shunt resistors across said meter.
Claim 5
Dependent Claim 31 words
Apparatus as set forth in claim 1 a ground detection component; a ground conductor for connecting said common juncture to an external ground, and including said ground detection component in series.
Claim 6
Dependent Claim 21 words
Apparatus as set forth in claim 4 said ground detection component having an impedance value higher than that of said phase-resistors.
Claim 7
Dependent Claim 51 words
Apparatus as set forth in claim 1 an amperage measuring circuit comprising a transformer having a split core member for selectively enclosing a test conductor, and a coil associated with said core defining a transformer secondary; and means connecting said coil in series with said meter and with isolation switch means.
Claim 8
Dependent Claim 32 words
Apparatus as set forth in claim 3 an amperage measuring circuit connected in series with said meter; isolation switch means for selectively isolating said amperage measuring circuit and the voltage measuring circuit.
Claim 9
Dependent Claim 54 words
Apparatus as set forth in claim 7 selector switch means for alternatively connecting selected shunt resistors across said meter; said selector switch means being operatively associated with said isolation switch means, for connecting first selected shunt resistors in said amperage measuring circuit, and for connecting second selected shunt resistors in said voltage measuring circuit.
Claim 10
Dependent Claim 54 words
Apparatus as set forth in claim 1 a resistance measuring circuit comprising means connecting a DC battery, a variable resistor, and isolation switch means in series with said meter; means connecting a shunt resistor across said meter; and means for isolating said shunt resistor from said meter circuit, for other functions of said apparatus.
Claim 11
Dependent Claim 44 words
Apparatus as set forth in claim 9 shunt resistor isolating means comprising a split-element jack normally opening said shunt resistor circuit; and said shunt resistor circuit being closed by a coacting connector plug for connecting said resistance circuit to the external circuit being tested.

References Cited (Backward Citations)

GB161167A Cited
US1684056A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1980-05-09 1980-11-08 1981-05-10 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1984-05-09 1984-11-08 1985-05-10 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1988-05-09 1988-11-08 1989-05-10 $7700.00 Window Closed / Lapsed

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