US3703662A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High speed quenching arrangement for a flash device
Assignee: Loewe Opta GmbH
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Filing: 1969-12-05
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Granted: 1972-11-21
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Expires: 1989-12-05
Abstract
Abstract A pulsed flash unit is provided with a photoelectrically controlled, interruptible thyristor gate whose transconductive path is connected in shunt with the flash tube for instantaneously quenching the light output from the flash tube when a predetermined quantity of emitted light has been monitored and integrated by the unit. A threshold-regulated transistor coupled to the output of the light integrator supplies a twostate control voltage to the control electrode of the thyristor so that the latter selectively provides a short and an open circuit across the flash tube.
Inventors
- 👤 Rolf Dister Dennewitz
- 👤 Lutz Breitkreuz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:00
CPC Classifications
H; H05; H05B; H05B41/00; H05B41/14; H05B41/30; H05B41/32; H05B41/325
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
225 words
A lightweight compact apparatus for rapidly terminating the output of a pulsed flash tube when a controllable quantity of light energy has been emitted therefrom, which comprises: photosensitive means for generating a control signal proportional to the integrated light energy contained in the emission from the flash tube; a normally disabled interruptable thyristor gate having a transconductive path whose resistance is low relative to the resistance of the flash tube and a control electrode responsive to signals of one state for keeping the gate closed and responsive to signals of the opposite state for opening the gate; resistive means for connecting the transconductive path of the thyristor gate directly across the flash tube to establish a shunting path for the tube, the resistance of the resistive means being sufficiently low so that the resistance of the shunting path is lower than that of the flash tube; normally disabled, threshold-regulated gating means having an input coupled to the output of the generating means, the gating means being triggerable into the one state when enabled and triggerable into the opposite state when subsequently excited by an input signal of a pre-determined value; means for enabling the generating means and the gating means at the start of the flash; and means for directly coupling the output of the gating means to the control electrode of the thyristor gate.
Claim 2
Dependent Claim
225 words
A lightweight compact apparatus for rapidly terminating the output of a pulsed flash tube when a controllable quantity of light energy has been emitted therefrom, which comprises: photosensitive means for generating a control signal proportional to the integrated light energy contained in the emission from the flash tube; a normally disabled interruptable thyristor gate having a transconductive path whose resistance is low relative to the resistance of the flash tube and a control electrode responsive to signals of one state for keeping the gate closed and responsive to signals of the opposite state for opening the gate; resistive means for connecting the transconductive path of the thyristor gate directly across the flash tube to establish a shunting path for the tube, the resistance of the resistive means being sufficiently low so that the resistance of the shunting path is lower than that of the flash tube; normally disabled, threshold-regulated gating means having an input coupled to the output of the generating means, the gating means being triggerable into the one state when enabled and triggerable into the opposite state when subsequently excited by an input signal of a pre-determined value; means for enabling the generating means and the gating means at the start of the flash; and means for directly coupling the output of the gating means to the control electrode of the thyristor gate.
Claim 3
Dependent Claim
225 words
A lightweight compact apparatus for rapidly terminating the output of a pulsed flash tube when a controllable quantity of light energy has been emitted therefrom, which comprises: photosensitive means for generating a control signal proportional to the integrated light energy contained in the emission from the flash tube; a normally disabled interruptable thyristor gate having a transconductive path whose resistance is low relative to the resistance of the flash tube and a control electrode responsive to signals of one state for keeping the gate closed and responsive to signals of the opposite state for opening the gate; resistive means for connecting the transconductive path of the thyristor gate directly across the flash tube to establish a shunting path for the tube, the resistance of the resistive means being sufficiently low so that the resistance of the shunting path is lower than that of the flash tube; normally disabled, threshold-regulated gating means having an input coupled to the output of the generating means, the gating means being triggerable into the one state when enabled and triggerable into the opposite state when subsequently excited by an input signal of a pre-determined value; means for enabling the generating means and the gating means at the start of the flash; and means for directly coupling the output of the gating means to the control electrode of the thyristor gate.
Claim 4
Dependent Claim
225 words
A lightweight compact apparatus for rapidly terminating the output of a pulsed flash tube when a controllable quantity of light energy has been emitted therefrom, which comprises: photosensitive means for generating a control signal proportional to the integrated light energy contained in the emission from the flash tube; a normally disabled interruptable thyristor gate having a transconductive path whose resistance is low relative to the resistance of the flash tube and a control electrode responsive to signals of one state for keeping the gate closed and responsive to signals of the opposite state for opening the gate; resistive means for connecting the transconductive path of the thyristor gate directly across the flash tube to establish a shunting path for the tube, the resistance of the resistive means being sufficiently low so that the resistance of the shunting path is lower than that of the flash tube; normally disabled, threshold-regulated gating means having an input coupled to the output of the generating means, the gating means being triggerable into the one state when enabled and triggerable into the opposite state when subsequently excited by an input signal of a pre-determined value; means for enabling the generating means and the gating means at the start of the flash; and means for directly coupling the output of the gating means to the control electrode of the thyristor gate.
Claim 5
Dependent Claim
117 words
Apparatus as defined in claim 1, in which the gating means comprises a transistor and in which the apparatus further comprises, in combination: a transformer having a primary winding in series with the flash tube and a secondary winding connected across the collector-emitter path of the transistor; rectifying means including a first capacitor connected across the secondary winding; a first voltage divider connected across the first capacitor; a second voltage divider including a photosensitive element connected across the first capacitor; means for coupling a tap of the first voltage divider to the base of the transistor; and a second capacitor connected between the tap of the first voltage divider and a tap of the second voltage divider.
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) | 1975-11-21 | 1976-05-22 | 1976-11-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-11-21 | 1980-05-22 | 1980-11-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-11-21 | 1984-05-22 | 1984-11-21 | $7700.00 | Window Closed / Lapsed |