Patent US3882358A successfully refreshed from Google Patents.
US3882358A
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US
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Anti-holdover charging circuit for flash lamp
Assignee: International Business Machines Corp
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Filing: 1973-06-26
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Granted: 1975-05-06
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Expires: 1993-06-26
Abstract
Abstract Charging circuit for a flash lamp in which flash holdover is prevented by establishing a high impedance charging circuit for a predetermined time after flash initiation to allow deionization of the lamp plasma and, after a predetermined time, establishing a low impedance charging circuit to provide a fast charging rate for the energy storage device. Impedance levels are changed in the circuit by gating a silicon controlled rectifier (SCR) with a control signal a predetermined time after flash initiation so as to bypass a high impedance circuit path in parallel therewith. As the energy storage device becomes fully charged, the SCR returns to its blocking condition, the control signal terminates and the lamp can be fired again.
Inventors
- 👤 Stephen Deskevich
- 👤 James C Peacock
- 👤 Richard F Tynan
- 👤 Alan D Wilson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 10:57
CPC Classifications
H; H05; H05B; H05B41/00; H05B41/14; H05B41/30
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
151 words
A circuit for permitting high frequency repetition of a flash lamp comprising: an energy storage circuit connected to said lamp; direct current charging means connected to said storage circuit, said charging means including a first constant impedance path and a second path with switch means having an on-state and an off-state in parallel with said first path to vary the rate of energy supplied to said storage circuit, said second path switch states being selectable in response to a control signal; trigger pulse means for initiating flashing of said lamp and discharge of said storage circuit; and circuit means including a delay circuit therein, said circuit means being connected to said trigger pulse means and responsive thereto for producing a said control signal at said charging means a predetermined time after said trigger pulse for selecting one of said switch states of said second path and changing said energy supply rate.
Claim 2
Dependent Claim
151 words
A circuit for permitting high frequency repetition of a flash lamp comprising: an energy storage circuit connected to said lamp; direct current charging means connected to said storage circuit, said charging means including a first constant impedance path and a second path with switch means having an on-state and an off-state in parallel with said first path to vary the rate of energy supplied to said storage circuit, said second path switch states being selectable in response to a control signal; trigger pulse means for initiating flashing of said lamp and discharge of said storage circuit; and circuit means including a delay circuit therein, said circuit means being connected to said trigger pulse means and responsive thereto for producing a said control signal at said charging means a predetermined time after said trigger pulse for selecting one of said switch states of said second path and changing said energy supply rate.
Claim 3
Dependent Claim
38 words
Apparatus as described in claim 1 wherein the impedance of said first path is of a value limiting energy flow to said storage means at a rate less than that required to sustain flash holdover in said lamp.
Claim 4
Dependent Claim
27 words
Apparatus as described in claim 1 further including means for terminating said control signal a predetermined time after said switch means has been selected to said on-state.
Claim 5
Dependent Claim
15 words
Apparatus as described in claim 1 wherein said switch means is a gate-controlled semiconductor device.
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) | 1978-05-05 | 1978-11-04 | 1979-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-05 | 1982-11-04 | 1983-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-05 | 1986-11-04 | 1987-05-06 | $7700.00 | Window Closed / Lapsed |