Patent US4251753A successfully refreshed from Google Patents.
US4251753A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Power supply circuit for strobo unit
Assignee: Olympus Corp
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Filing: 1979-04-05
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Granted: 1981-02-17
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Expires: 1999-04-05
Abstract
Abstract A power supply circuit for strobo unit includes a DC-DC converter which steps up a low voltage from a d.c. source to a higher voltage. The converter comprises an oscillation transformer, a PNP transistor and an NPN transistor, both of which are used to form an oscillation circuit. The circuit arrangement provides a stabilized oscillation and eliminates the likelihood of producing an electric shock.
Inventors
- 👤 Isao Kondo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 05:35
CPC Classifications
H; H02; H02M; H02M3/00; H02M3/22; H02M3/24; H02M3/28; H02M3/325; H02M3/335; H02M3/338; H02M3/3381; H05; H05B; H05B41/00; H05B41/14; H05B41/30; H05B41/32
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
92 words
A power supply circuit for strobo unit comprising a low voltage d.c. source, an oscillation transformer having a primary winding, a step-up secondary winding and a feedback winding, an NPN transistor connected in series across the source and the primary winding of the oscillation transformer, a PNP transistor having its base connected with one end of the feedback winding and its collector connected with the base of the NPN transistor, and a rectifier element for rectifying a high voltage which is induced across the secondary winding to feed a flash discharge circuit.
Claim 2
Dependent Claim
92 words
A power supply circuit for strobo unit comprising a low voltage d.c. source, an oscillation transformer having a primary winding, a step-up secondary winding and a feedback winding, an NPN transistor connected in series across the source and the primary winding of the oscillation transformer, a PNP transistor having its base connected with one end of the feedback winding and its collector connected with the base of the NPN transistor, and a rectifier element for rectifying a high voltage which is induced across the secondary winding to feed a flash discharge circuit.
Claim 3
Dependent Claim
52 words
A power supply circuit according to claim 1 in which the NPN transistor has its base connected with the collector of the PNP transistor through a resistor, its collector connected with one end of the primary winding, and its emitter connected with the negative terminal of the source through a power switch.
Claim 4
Dependent Claim
49 words
A power supply circuit according to claim 1 in which the PNP transistor has its base connected with one end of the feedback winding, its collector connected with the base of the NPN transistor through a resistor, and its emitter connected with the positive terminal of the d.c. source.
Claim 5
Dependent Claim
96 words
A power supply circuit according to claim 1 in which the primary winding has its one end connected with the collector of the NPN transistor and its other end connected with the positive terminal of the d.c source and wherein the secondary winding has its one end connected with the rectifier element and its other end connected with the base of the PNP transistor together with one end of the feedback winding, the other end of the feedback winding being connected with the negative terminal of the d.c. source through a resistor and a power switch.
Claim 6
Dependent Claim
97 words
A power source circuit according to claim 1 in which the primary winding has its one end connected with the collector of the NPN transistor and its other end connected with the positive terminal of the d.c source while the secondary winding has its one end connected with the rectifier element and its other end connected with one end of the feedback winding and also connected with the negative terminal of the d.c. source through a resistor and a power switch, the other end of the feedback winding being connected with the base of the PNP transistor.
Claim 7
Dependent Claim
16 words
A power supply circuit according to claim 1 in which the rectifier element comprises a diode.
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) | 1984-02-17 | 1984-08-18 | 1985-02-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-02-17 | 1988-08-18 | 1989-02-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-02-17 | 1992-08-18 | 1993-02-17 | $7700.00 | Window Closed / Lapsed |