US3781667A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High voltage resonant testing circuit
Assignee: General Electric Co
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Filing: 1972-03-17
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Granted: 1973-12-25
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Expires: 1992-03-17
Abstract
Abstract A transformer has two secondary windings, a high voltage secondary connected across a capacitive load being tested, and a low voltage secondary connected across a variable reactor which is tuned to resonance with the capacitive load. A voltage regulator in the transformer primary winding circuit is utilized to raise the voltage across the capacitive load to the test value after resonance has been achieved. The variable reactor can be replaced by a fixed reactor and a second voltage regulator.
Inventors
- 👤 C Tuttle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:55
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/40; G01R31/42; G01R31/12; G01R31/1227; G01R31/1263; G01R31/1272; G01R31/14
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
245 words
A high voltage resonant testing circuit for testing the dielectric strength of electric insulation of a reactive load and having the KVA power supplied from the power source being substantially less than the KVA power requirements of the load to be tested, and comprising a single transformer having a low voltage primary winding, a low voltage secondary winding and a very high voltage secondary winding across which is connected a reactive load to be tested for the dielectric strength of its electric insulation, means connected to said low voltage primary winding for supplying an adjustable voltage alternating current power thereto, and means connected in circuit relationship with said low voltage secondary winding for providing a variable reactance of a type opposite to that of the reactive load and adapted to be tuned to resonance with the reactive load and thereby increasing the phase angle between the transformer primary and secondary currents to a maximum so as to substantially reduce the KVA power required from said primary winding during testing of the dielectric strength of the electric insulation of the reactive load, said variable reactance means being low voltage rated as compared to a predetermined very high voltage in the order of 200 kilovolts developed across the reactive load at the condition of resonance during testing of the reactive load, said low voltage rated variable reactance means providing greater ease in obtaining precise variatIon in voltage as compared to a high voltage rated variable reactance means.
Claim 2
Dependent Claim
245 words
A high voltage resonant testing circuit for testing the dielectric strength of electric insulation of a reactive load and having the KVA power supplied from the power source being substantially less than the KVA power requirements of the load to be tested, and comprising a single transformer having a low voltage primary winding, a low voltage secondary winding and a very high voltage secondary winding across which is connected a reactive load to be tested for the dielectric strength of its electric insulation, means connected to said low voltage primary winding for supplying an adjustable voltage alternating current power thereto, and means connected in circuit relationship with said low voltage secondary winding for providing a variable reactance of a type opposite to that of the reactive load and adapted to be tuned to resonance with the reactive load and thereby increasing the phase angle between the transformer primary and secondary currents to a maximum so as to substantially reduce the KVA power required from said primary winding during testing of the dielectric strength of the electric insulation of the reactive load, said variable reactance means being low voltage rated as compared to a predetermined very high voltage in the order of 200 kilovolts developed across the reactive load at the condition of resonance during testing of the reactive load, said low voltage rated variable reactance means providing greater ease in obtaining precise variatIon in voltage as compared to a high voltage rated variable reactance means.
Claim 3
Dependent Claim
30 words
The circuit set forth in claim 1 wherein the reactive load is a capacitive reactance load, and said low voltage rated variable reactance means is a variable inductive reactance means.
Claim 4
Dependent Claim
88 words
The circuit set forth in claim 2 wherein said adjustable voltage alternating power supplying means consists of a source of alternating current voltage of fixed frequency and amplitude, and means connected in circuit relationship between said source and said primary winding for adjusting the alternating current voltage applied thereto, the voltage being increased from zero and maintained at a very low value prior to achieving resonance, and being increased to a low value necessary to develop the predetermined very high voltage across the capacitive load after achieving resonance.
Claim 5
Dependent Claim
46 words
The circuit set forth in claim 3 wherein said primary winding voltage adjusting means is a voltage regulator, and the KVA power rating of said voltage regulator and said transformer primary winding is in the order of 1/20 of the KVA power requirement of the load.
Claim 6
Dependent Claim
19 words
The circuit set forth in claim 3 wherein said primary winding voltage adjusting means is an induction voltage regulator.
Claim 7
Dependent Claim
44 words
The circuit set forth in claim 3 wherein said low voltage rated variable reactance means is a variable inductive reactor having a voltage rating substantially equal to the low voltage rating of said low voltage secondary winding, and connected in series circuit relationship therewith.
Claim 8
Dependent Claim
64 words
The circuit set forth in claim 3 wherein said low voltage rated variable reactance means consists of a fixed inductive reactor, and means connected in circuit relationship between said low voltage secondary winding and said fixed inductive reactor for adjusting the alternating current voltage applied thereto and thereby varying the inductance in said low voltage secondary winding for achieving resonance with the capacitive load.
Claim 9
Dependent Claim
47 words
The circuit set forth in claim 6 wherein the voltage rating of said variable inductive reactor is in the order of 1/200 of the predetermined very high voltage developed across the capacitive load at the condition of resonance whereby said reactor is a relatively simple, inexpensive apparatus.
Claim 10
Dependent Claim
47 words
The circuit set forth in claim 7 wherein the voltage rating of said fixed inductive reactor is in the order of 1/200 of the predetermined very high voltage developed across the capacitive load at the condition of resonance whereby said reactor is a relatively simple, inexpensive apparatus.
Claim 11
Dependent Claim
30 words
The circuit set forth in claim 1 wherein the reactive load is an inductive reactance load, and said low voltage rated variable reactance means is a variable capacitive reactance means.
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) | 1976-12-24 | 1977-06-25 | 1977-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-24 | 1981-06-25 | 1981-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-24 | 1985-06-25 | 1985-12-25 | $7700.00 | Window Closed / Lapsed |