US3689825A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Inverter drive circuit
Assignee: Design Elements Inc
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Filing: 1971-09-27
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Granted: 1972-09-05
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Expires: 1991-09-27
Abstract
Abstract In a voltage feedback, one transformer, transistor inverter circuit, an improved drive circuit having a first resistor connected between the center tap of the base circuit winding and the center tap of the collector circuit winding and having a series first bipolar junction transistor and second resistor connected between the center tap of the base winding and the interconnected common emitter terminals of a push-pull connected pair of transistors. The first resistor has a substantially greater resistance than the second resistor and the first transistor is polarized to permit base current to flow around the base circuit loops. The first transistor is switched by a pair of diodes connected between its base and the opposite ends of the base circuit winding. Base current is limited by a series connected pair of diodes connected between the base and said interconnected common emitter terminals of the push-pull transistors.
Inventors
- 👤 Edwin E Mason
- 👤 Ross C Libby
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 16:14
CPC Classifications
H; H02; H02M; H02M3/00; H02M3/22; H02M3/24; H02M3/28; H02M3/325; H02M3/335; H02M3/338; H02M3/3382; H02M3/3384
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
184 words
In an inverter of the type having at least two magnetically coupled, center tapped windings and a pair of push-pull connected active elements connected for free running oscillation, the active elements having their input terminals coupled to opposite sides of an input one of said windings and their output terminals connected to opposite sides of the other of said windings, an improved drive circuit comprising: a. a first resistance connected between the center taps of said windings; b. a series connected second resistance and an electronic switch means connected between the center tap of the input one of said windings and the common terminals of said active elements, said switch means having a control input terminal and being connected in a polarity to permit current flow around an input circuit loop comprising said switch means, said second resistance, said input winding and the input of one of said active elements; and c. a pair of diodes connected between the control input terminal of said switch means and opposite ends of one of said windings, said diodes polarized to permit actuation of said switch means.
Claim 2
Dependent Claim
184 words
In an inverter of the type having at least two magnetically coupled, center tapped windings and a pair of push-pull connected active elements connected for free running oscillation, the active elements having their input terminals coupled to opposite sides of an input one of said windings and their output terminals connected to opposite sides of the other of said windings, an improved drive circuit comprising: a. a first resistance connected between the center taps of said windings; b. a series connected second resistance and an electronic switch means connected between the center tap of the input one of said windings and the common terminals of said active elements, said switch means having a control input terminal and being connected in a polarity to permit current flow around an input circuit loop comprising said switch means, said second resistance, said input winding and the input of one of said active elements; and c. a pair of diodes connected between the control input terminal of said switch means and opposite ends of one of said windings, said diodes polarized to permit actuation of said switch means.
Claim 3
Dependent Claim
45 words
An inverter drive circuit according to claim 1 wherein said switch means is a first bipolar junction transistor connected in a common emitter configuration having its base connected to said diodes and said diodes connected to opposite sides of the input one of said windings.
Claim 4
Dependent Claim
18 words
A circuit according to claim 2 wherein a current limiting resistance is interposed in series with said diodes.
Claim 5
Dependent Claim
47 words
A circuit according to claim 2 wherein a current limiting resistance is interposed in series with said diodes, and wherein a filter capacitance is connected parallel to said series second resistance and switch means and another filter capacitance is connected between said diodes and a ground terminal.
Claim 6
Dependent Claim
17 words
A circuit according to claim 4 wherein said first resistance is substantially greater than said second resistance.
Claim 7
Dependent Claim
46 words
A circuit according to claim 2 wherein said second resistance has one terminal connected to the emitter of said first transistor and a pair of series connected, base current limiting diodes are connected between the other terminal of said resistance, and the base of said transistor.
Claim 8
Dependent Claim
44 words
A circuit according to claim 2 wherein said active elements are second and third bipolar junction transistors and said first transistor is polarized to permit current flow around the input circuit loops of and through the base-emitter junctions of said second and third transistors.
References Cited (Backward Citations)
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US3151287A
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US3305760A
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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) | 1975-09-05 | 1976-03-06 | 1976-09-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-05 | 1980-03-06 | 1980-09-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-05 | 1984-03-06 | 1984-09-05 | $7700.00 | Window Closed / Lapsed |