US3764849A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronic flash charging and triggering circuitry
Assignee: Minolta Co Ltd
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Filing: 1972-03-24
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Granted: 1973-10-09
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Expires: 1992-03-24
Abstract
Abstract A charging and triggering circuit for an electronic flash device of the type in which a voltage for triggering the flash is stored by a condenser comprises structure for generating a feedback signal in response to the triggering of the flash tube to actuate an oscillating circuit for charging the condenser with the rectified oscillatory output. A circuit disables the oscillator when the condenser has reached a voltage sufficient to actuate the flash tube thereby reducing the power consumed from a battery which energizes the circuitry.
Inventors
- 👤 Y Ohta
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:23
CPC Classifications
H; H05; H05B; H05B41/00; H05B41/14; H05B41/30; H05B41/32
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
145 words
A charging and triggering circuit for an electronic flash device comprising: an electric power source; a transformer connected to said power source and including a winding for generating an oscillatory output; means for rectifying said oscillatory output; a flash circuit including means for storing the rectified output of said rectifying means, a flash tube, said transformer including primary and secondary windings for triggering said flash tube, and said transformer further including an additional winding for generating a feedback signal in response to the triggering of said flash tube; and means for controlling said oscillating means including an SCR having its gate connected to said additional winding to be made conductive by said feedback signal to oscillate said oscillating means, and said SCR is made non-conductive with said means for storing at a voltage sufficient to actuate said flash tube whereby said oscillating means are de-actuated.
Claim 2
Dependent Claim
145 words
A charging and triggering circuit for an electronic flash device comprising: an electric power source; a transformer connected to said power source and including a winding for generating an oscillatory output; means for rectifying said oscillatory output; a flash circuit including means for storing the rectified output of said rectifying means, a flash tube, said transformer including primary and secondary windings for triggering said flash tube, and said transformer further including an additional winding for generating a feedback signal in response to the triggering of said flash tube; and means for controlling said oscillating means including an SCR having its gate connected to said additional winding to be made conductive by said feedback signal to oscillate said oscillating means, and said SCR is made non-conductive with said means for storing at a voltage sufficient to actuate said flash tube whereby said oscillating means are de-actuated.
Claim 3
Dependent Claim
21 words
A circuit as in claim 1 further comprising means for initiating the operation of said transformer for generating an oscillatory output.
Claim 4
Dependent Claim
28 words
A circuit as in claim 2 further comprising means for maintaining said SCR conductive at all operating frequencies of said transformer during charging of said means for storing.
Claim 5
Dependent Claim
61 words
A circuit as in claim 2 wherein said flash circuit further includes means for indicating the condition of said means for storing and means interconnecting said indicating means with said SCR, whereby said SCR is inoperative to actuate said transfoRmer with the actuation of said means for indicating and are operative with said means for indicating non-conductive to actuate said transformer.
Claim 6
Dependent Claim
25 words
A circuit as in claim 3 wherein said means for maintaining conduction of said SCR at all frequencies is a capacitor connected across said SCR.
Claim 7
Dependent Claim
26 words
A circuit as in claim 1 further comprising means for indicating that said means for storing is at a voltage sufficient to actuate said flash tube.
Claim 8
Dependent Claim
53 words
A circuit as in claim 4 wherein said means for indicating is parallelly connected with said transformer, said means for initiating operation of said transformer comprising a manually operated switch interconnecting the gate of said SCR to said power source, and further comprising a circuit interconnecting said gate with said means for indicating.
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) | 1976-10-08 | 1977-04-09 | 1977-10-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-08 | 1981-04-09 | 1981-10-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-08 | 1985-04-09 | 1985-10-09 | $7700.00 | Window Closed / Lapsed |