US3676766A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multiphase alternating current regulation system for transformer-coupled loads
Assignee: Robicon Corp
•
Filing: 1970-12-11
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Granted: 1972-07-11
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Expires: 1990-12-11
Abstract
Abstract In a multiphase alternating current regulating system employing controlled rectifiers operated in accordance with phase commutation techniques, the improvement of circuitry for eliminating direct current components across loads supplied by the three-phase system which would otherwise occur when the loads become unbalanced.
Inventors
- 👤 Ronald C Blackmond
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 16:46
CPC Classifications
H; H02; H02J; H02J3/00; H02J3/26; H02M; H02M1/00; H02M1/08; H02M1/084; Y; Y02; Y02E; Y02E40/00; Y02E40/50
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
165 words
In a current regulating system of the type in which alternating current is supplied through controlled rectifiers to a plurality of loads and wherein each of said rectifiers has an anode terminal and a cathode terminal; the combination of a controllable firing circuit connected to said controlled rectifiers whereby current supplied to the load is controlled by varying the firing angle of said controlled rectifiers, operational amplifier meanS coupled to said controlled rectifiers for comparing the amplitudes of the voltages appearing at corresponding terminals of at least two of said controlled rectifiers, said operational amplifier means being adapted to produce an output signal when the amplitudes of the voltages compared thereby are not the same indicating the existence of a direct current component across a load, and means including saturable magnetic amplifying means coupled to the output of said operational amplifier means and responsive to said output signal for varying the firing angles of said controlled rectifiers until said direct current component no longer exists.
Claim 2
Dependent Claim
165 words
In a current regulating system of the type in which alternating current is supplied through controlled rectifiers to a plurality of loads and wherein each of said rectifiers has an anode terminal and a cathode terminal; the combination of a controllable firing circuit connected to said controlled rectifiers whereby current supplied to the load is controlled by varying the firing angle of said controlled rectifiers, operational amplifier meanS coupled to said controlled rectifiers for comparing the amplitudes of the voltages appearing at corresponding terminals of at least two of said controlled rectifiers, said operational amplifier means being adapted to produce an output signal when the amplitudes of the voltages compared thereby are not the same indicating the existence of a direct current component across a load, and means including saturable magnetic amplifying means coupled to the output of said operational amplifier means and responsive to said output signal for varying the firing angles of said controlled rectifiers until said direct current component no longer exists.
Claim 3
Dependent Claim
56 words
The current regulating system of claim 1 wherein the current is supplied in a three-phase system and wherein said operational amplifier means includes two operational amplifiers one of which compares the amplitudes of a first and second of said phases and the second of which compares the amplitudes of the second and third of said phases.
Claim 4
Dependent Claim
61 words
The current regulating system of claim 2 wherein said saturable magnetic amplifying means includes three separate saturable magnetic amplifiers, two of which are connected to the output of an associated one of said operational amplifiers through respective first impedance elements and the third of which is connected to the outputs of both of said operational amplifiers through respective second impedance elements.
Claim 5
Dependent Claim
22 words
The current regulating system of claim 3 wherein said second impedance elements have impedance values twice those of the first impedance elements.
Claim 6
Dependent Claim
42 words
The current regulating system of claim 3 wherein said first and second magnetic amplifiers act to shift the firing angle of said controlled rectifiers in one direction while said third magnetic amplifier acts to shift said firing angle in the opposite direction.
Claim 7
Dependent Claim
23 words
The current regulating system of claim 1 including transformer means for supplying alternating current from said controlled rectifiers to a plurality of loads.
Claim 8
Dependent Claim
16 words
The current regulating system of claim 1 including diodes connected in shunt with said controlled rectifiers.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-11 | 1976-01-10 | 1976-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-11 | 1980-01-10 | 1980-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-11 | 1984-01-10 | 1984-07-11 | $7700.00 | Window Closed / Lapsed |