US3697872A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit for measuring the power consumption of three phase loads
Assignee: Robert Bosch GmbH
•
Filing: 1971-01-28
•
Granted: 1972-10-10
•
Expires: 1991-01-28
Abstract
Abstract Two of the three phases are connected in series with the primary of a respective current transformer, the secondary of each transformer being connected to a respective current divider that separates the secondary current into an in-phase component and into an out of phase component, the in-phase component of one current divider and the out of phase component of the other current divider being connected to one end of the current path of a watt meter, the other end being connected to the out of phase component of the one current divider and the in-phase component of the other current divider. The voltage path of the watt meter is connected across the load.
Inventors
- 👤 Jurgen Schulz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 11:55
CPC Classifications
G; G01; G01R; G01R21/00; G01R11/00; G01R11/36; G01R11/40
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
165 words
A circuit for measuring the power input from a three phase system to a three phase load, such as a three phase motor, comprising, in combination, first and second current transformer means each comprising a primary winding for connection in series with one of the three phases connected to the load, and a secondary winding; first and second current divider means respectively connected with the secondary windings of said first and second transformer means for dividing the secondary currents associated with said secondary windings into in-phase and out-ofphase current components, each of said current divider means comprising in-phase and out-of-phase branches respectively carrying the in-phase and out-of-phase current components; a single-phase wattmeter including a wattmeter current path connected with said in-phase branches, whereby to carry the resultant of said in-phase current components; and return-flow current path means connected with said out-of-phase branches and with said secondary windings and providing a return-flow path for said out-of-phase current components from said out-of-phase branches to said secondary windings.
Claim 2
Dependent Claim
165 words
A circuit for measuring the power input from a three phase system to a three phase load, such as a three phase motor, comprising, in combination, first and second current transformer means each comprising a primary winding for connection in series with one of the three phases connected to the load, and a secondary winding; first and second current divider means respectively connected with the secondary windings of said first and second transformer means for dividing the secondary currents associated with said secondary windings into in-phase and out-ofphase current components, each of said current divider means comprising in-phase and out-of-phase branches respectively carrying the in-phase and out-of-phase current components; a single-phase wattmeter including a wattmeter current path connected with said in-phase branches, whereby to carry the resultant of said in-phase current components; and return-flow current path means connected with said out-of-phase branches and with said secondary windings and providing a return-flow path for said out-of-phase current components from said out-of-phase branches to said secondary windings.
Claim 3
Dependent Claim
27 words
A circuit as defined in claim 1, wherein each of said current dividers includes reactive and resistive means to obtain said in-phase and out of phase components.
Claim 4
Dependent Claim
25 words
A circuit as defined in claim 2, wherein each of said current dividers includes a branch with resistive means and a branch with resistive-reactive means.
Claim 5
Dependent Claim
19 words
A circuit as defined in claim 3, wherein said resistive-reactive means includes a resistive means and an inductive means.
Claim 6
Dependent Claim
13 words
A circuit as defined in claim 4, wherein said inductive means is adjustable.
Claim 7
Dependent Claim
30 words
A circuit as defined in claim 1, said current path of said single-phase wattmeter having one end connected with said in-phase branches and another end connected with said out-of-phase branches.
Claim 8
Dependent Claim
39 words
A circuit as defined in claim 1, wherein said watt meter has a voltage path, and further including a Y connection for the three phase system, the common junction of said Y connection being connected to said voltage path.
Claim 9
Dependent Claim
16 words
A circuit as defined in claim 7, wherein said voltage path is connected across the load.
Claim 10
Dependent Claim
62 words
A circuit as defined in claim 1, wherein said wattmeter has a voltage path, and including a Y connection for the three phase system, the common junction of said Y connection being connected to one end of said voltage path; and a voltage divider having resistive and reactive means connecting the other end of said voltage path to the three phase system.
Claim 11
Dependent Claim
95 words
A circuit as defined in claim 9, wherein said Y connection includes said voltage path and also includes first and second resistors, each of said first and second resistors connected to a different one of the three phases, and said voltage path includes a third resistor and a first capacitor, each connected to a different one of the three phases, said third resistor and first capacitor being connected to said other end of said voltage path, all three phases being connected to at least one of said first, second, and third resistors and first capacitor.
Claim 12
Dependent Claim
37 words
A circuit as defined in claim 10, further including a second capacitor shunted across said voltage path for correcting phase errors introduced by the loading of both said voltage divider and any inductance in said voltage path.
Claim 13
Dependent Claim
18 words
A circuit as defined in claim 1, including means for correcting phase errors caused by said current path.
Claim 14
Dependent Claim
30 words
A circuit as defined in claim 12, wherein said means for correcting phase errors caused by said current path is an adjustable inductor connected in series with said current path.
References Cited (Backward Citations)
US3497804A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-10 | 1976-04-10 | 1976-10-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-10 | 1980-04-10 | 1980-10-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-10 | 1984-04-10 | 1984-10-10 | $7700.00 | Window Closed / Lapsed |