Patent USRE21827E successfully refreshed from Google Patents.
Patent US3872370A successfully refreshed from Google Patents.
US3872370A
Expired / Lapsed
US
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High-voltage D.C. generator, specially for energizing an electrostatic apparatus
Assignee: REDELEC A RESPONSABILITE Ltee Ste
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Filing: 1973-03-02
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Granted: 1975-03-18
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Expires: 1993-03-02
Abstract
Abstract This invention relates to a high-voltage d.c. generator capable of at least a few tens of kilovolts for energizing an electrostatic apparatus of the type comprising a charge electrode, such as paint spraying guns, powdering apparatus, electrostatic filter means. This generator comprises a selfoscillating circuit producing an alternating current having a frequency of at least 20,000 Hz. A single transformer is located in close vicinity of this self-oscillating circuit. Its primary winding is connected to the output of the self-oscillating circuit. An adder-rectifier consisting essentially of miniaturized capacitors of very low values, and of miniaturized solid-state diodes, having very low self-capacities, is incorporated in the electrostatic apparatus, very close to its charge electrode. The output of the adder-rectifier is connected directly to the charge electrode. A flexible coaxial cable of predetermined length is disposed for connecting the secondary winding of the transformer directly to the input of the adderrectifier.
Inventors
- 👤 Alain Regnault
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 21:01
CPC Classifications
H; H02; H02M; H02M3/00; H02M3/22; H02M3/24; H02M3/28; H02M3/325; H02M3/335; H02M3/338; H02M3/3382; H02M3/3384; B; B05; B05B; B05B5/00; B05B5/025; B05B5/053; B05B5/0531; H02M7/00; H02M7/02; H02M7/04; H02M7/06; H02M7/10; H02M7/103; H02M7/106
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
215 words
A high-voltage d.c. generator capable of at least a few tens of kilovolts, for energizing an electrostatic apparatus having a charge electrode, specially an electrostatic paint spraying apparatus, and electrostatic powdering apparatus, an electrostatic filtering apparatus, and the like, said generator comprising a self-oscillating circuit producing an alternating current having a frequency of at least 20,000 Hz, a single transformer located in the vicinity of said self-oscillating circuit and having a primary winding connected to the output of said self-oscillating circuit, and a secondary winding, at least one dielectric plate having deposited on both faces a plurality of conductive layers forming the respective plates of miniaturized capacitors of very low values, another plurality of miniaturized solid-state diodes, having very low self-capacities, said diodes being directly soldered to said capacitor plates to form an adder-rectifier of the type comprising a number of identical stages connected in parallel to one another, which adder-rectifier is embedded in a block of molded resin or resin compound and is incorporated in the electrostatic apparatus in a very close relationship to its charge electrode, the output of said adder-rectifier being connected directly to said charge electrode, and a flexible coaxial cable having a predetermined length, said cable connecting the secondary winding of said transformer directly to the input of said adder-rectifier.
Claim 2
Dependent Claim
215 words
A high-voltage d.c. generator capable of at least a few tens of kilovolts, for energizing an electrostatic apparatus having a charge electrode, specially an electrostatic paint spraying apparatus, and electrostatic powdering apparatus, an electrostatic filtering apparatus, and the like, said generator comprising a self-oscillating circuit producing an alternating current having a frequency of at least 20,000 Hz, a single transformer located in the vicinity of said self-oscillating circuit and having a primary winding connected to the output of said self-oscillating circuit, and a secondary winding, at least one dielectric plate having deposited on both faces a plurality of conductive layers forming the respective plates of miniaturized capacitors of very low values, another plurality of miniaturized solid-state diodes, having very low self-capacities, said diodes being directly soldered to said capacitor plates to form an adder-rectifier of the type comprising a number of identical stages connected in parallel to one another, which adder-rectifier is embedded in a block of molded resin or resin compound and is incorporated in the electrostatic apparatus in a very close relationship to its charge electrode, the output of said adder-rectifier being connected directly to said charge electrode, and a flexible coaxial cable having a predetermined length, said cable connecting the secondary winding of said transformer directly to the input of said adder-rectifier.
Claim 3
Dependent Claim
98 words
A generator as set forth in claim 1, wherein the cable connecting the secondary winding of said transformer to the input of said adder-rectifier is a coaxial cable having a central conductor and a conducting braid surrounding said central conductor, said braid being grounded at the end of said cable which is connected to the secondary winding of said transformer, and being connected to the frame of the electrostatic apparatus at the other end of said cable, one of the input terminals of said adder-rectifier being also connected to said frame of the electrostatic apparatus through a capacitor.
Claim 4
Dependent Claim
74 words
A generator as set forth in claim 2, wherein a self-inductance connected in series with a capacitor is inserted between the ground and the end of the central conductor of said coaxial cable which is connected to the secondary winding of said transformer, the value of said self-inductance being selected to tune the circuit comprising said self-oscillating circuit, said transformer and said coaxial cable at a desired high frequency of at least 20,000 Hz.
Claim 5
Dependent Claim
53 words
A generator as set forth in claim 1, wherein a first resistor is inserted between the ground and one end of the secondary winding of said transformer, and means are provided for regulating the high frequency voltage produced by said self-oscillating circuit from the d.c. component of the voltage across said first resistor.
Claim 6
Dependent Claim
102 words
A generator as set forth in claim 4, wherein said regulating means comprises a differential amplifier having a positive terminal and a negative terminal, a second resistor inserted between said positive terminal and the connecting point of said first resistor and said secoNdary winding of said transformer, an inductance and a capacitor inserted in series with each other between said negative terminal and said connecting point of said first resistor and said secondary winding of said transformer, said inductance and said capacitor having values selected for forming a resonant circuit tuned to the frequency of the current produced by said self-oscillating circuit.
Claim 7
Dependent Claim
48 words
A generator as set forth in claim 1, wherein each stage of said adder-rectifier consists of two half-stages comprising each two capacitors and a diode inserted between said two capacitors, the two half-stages of each stage being interconnected by a resistor having a value of a few megohms.
Claim 8
Dependent Claim
57 words
A generator as set forth in claim 1, wherein said adder-rectifier comprises at least one printed-circuit plate having deposited on one face a conductive layer forming a common first plate for all the capacitors, separate conductive layers being deposited on the other face of said printed circuit plate for forming the respective second plates of said capacitors.
Claim 9
Dependent Claim
83 words
A generator as set forth in claim 7, wherein said adder-rectifier comprises, embedded in a block of molded resin or resin compound, two printed-circuit plates disposed in a parallel and spaced relationship to each other, the common first plates and the separate second plates of said capacitors being disposed respectively on the outer faces and on the inner faces of said printed circuit plates, the resistors and diodes being soldered directly to said second plates and being disposed between said two printed-circuit plates.
Claim 10
Dependent Claim
41 words
A generator as set forth in claim 1, wherein a protecting resistor having a value of 100 to 200 kiloohms per kilovolt of output voltage is inserted between the output of said adder-rectifier and the charge electrode of the electrostatic apparatus.
Claim 11
Dependent Claim
23 words
A generator as set forth in claim 9, wherein at least one diode is inserted between said protecting resistor and said charge electrode.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-17 | 1978-09-16 | 1979-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-17 | 1982-09-16 | 1983-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-17 | 1986-09-16 | 1987-03-18 | $7700.00 | Window Closed / Lapsed |