US3864606A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Compensated sequencing circuit for firing photoflash lamps
Assignee: General Electric Co
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Filing: 1972-10-24
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Granted: 1975-02-04
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Expires: 1992-10-24
Abstract
Abstract A circuit for compensating a photoflash lamp sequencing flashing circuit, with respect to changes in temperature, voltage and current, to insure flashing of a single lamp of a flash lamp array each time a flash picture is taken. A transistorized compensation circuit applies a compensating voltage to a sequencing transistor in each stage of the sequencing circuit.
Inventors
- 👤 Donald L Watrous
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 14:34
CPC Classifications
F; F42; F42D; F42D1/00; F42D1/04; F42D1/045; F42D1/05; F42D1/055; F23; F23Q; F23Q7/00; F23Q7/02
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
204 words
In a circuit for sequentially flashing a plurality of photoflash lamps and comprising a plurality of electrical terminals adapted to be connected respectively to filaments of said flash lamps, a pair of operating voltage terminals, and a sequencing circuit comprising a plurality of semiconductor switch devices connected in circuit paths respectively between said plurality of electrical terminals and one of said operating voltage terminals, said sequencing circuit further comprising a plurality of sequencing circuit stages successively connected from one to another of said semiconductor switch devices, each of said sequencing stages including a semiconductor sequencing device the operating characteristics of which are subject to change with changes in operating temperature and voltage, the improvement comprising a temperature and voltage compensator circuit comprising a transistor amplifier including a current feed means, electrical means connecting said amplifier and its current feed means in series in a circuit across said operating voltage terminals thereby causing a compensating voltage to be produced in said current feed means, and electrical means connecting a point of said current feed means that is between said operating voltage terminals to an electrode of at least one of said semiconductor sequencing devices so as to apply said compensating voltage to said sequencing device.
Claim 2
Dependent Claim
204 words
In a circuit for sequentially flashing a plurality of photoflash lamps and comprising a plurality of electrical terminals adapted to be connected respectively to filaments of said flash lamps, a pair of operating voltage terminals, and a sequencing circuit comprising a plurality of semiconductor switch devices connected in circuit paths respectively between said plurality of electrical terminals and one of said operating voltage terminals, said sequencing circuit further comprising a plurality of sequencing circuit stages successively connected from one to another of said semiconductor switch devices, each of said sequencing stages including a semiconductor sequencing device the operating characteristics of which are subject to change with changes in operating temperature and voltage, the improvement comprising a temperature and voltage compensator circuit comprising a transistor amplifier including a current feed means, electrical means connecting said amplifier and its current feed means in series in a circuit across said operating voltage terminals thereby causing a compensating voltage to be produced in said current feed means, and electrical means connecting a point of said current feed means that is between said operating voltage terminals to an electrode of at least one of said semiconductor sequencing devices so as to apply said compensating voltage to said sequencing device.
Claim 3
Dependent Claim
69 words
A circuit as claimed in claim 1, including a current-sensing element connected in a current path between said flash lamps and a first one of said operating voltage terminals, and electrical means connecting said amplifier and its current feed means in series between the second one of said operating voltage terminals and the end of said current sensing element which is nearest in the circuit to said flash lamps.
Claim 4
Dependent Claim
118 words
A circuit as claimed in claim 1, in which said amplifier comprises means connecting a first end of said current feed means to a first one of said operating voltage terminals, a pair of series-connected resistors connected at one end thereof to the second end of said current feed means, electrical means connecting the other end of said pair of resistors to the second one of said operating voltage terminals, and a transistor having a base electrode connected to the junction of said pair of resistors, a collector electrode connected to said second end of the current feed means and electrical means connecting the emitter electrode of said transistor to said second one of the operating voltage terminals.
Claim 5
Dependent Claim
54 words
A circuit as claimed in claim 3, in which said amplifier comprises a second transistor having a base electrode connected to the emitter electrode of the first transistor, a collector electrode connected to the collector electrode of the first transistor, and an emitter electrode connected to said other end of the pair of transistors.
Claim 6
Dependent Claim
69 words
A circuit as claimed in claim 3, including a current-sensing element connected in a current path between said flash lamps and said first one of the operating voltage terminals, and electrical means connecting said amplifier and its current feed means in series between said second one of the operating voltage terminals and the end of said current sensing element which is nearest in the circuit to said flash lamps.
Claim 7
Dependent Claim
101 words
A circuit as claimed in claim 1, in which each of said semiconductor switch devices is an SCR having anode and cathode current electrodes and in which each of said semiconductor sequencing devices is a transistor, said circuit including electrical means connecting the base electrode of each sequencing transistor to a current electrode of the preceding SCR and electrical means connecting the collector electrode of each sequencing transistor to the gate electrode of the succeeding SCR, and electrical means connecting the emitter electrodes of all of said sequencing transistors to said point of the current feed means in the compensator circuit.
Claim 8
Dependent Claim
68 words
A Circuit as claimed in claim 6, including a current-sensing element connected in a current path between said flash lamps and a first one of said operating voltage terminals, and electrical means connecting said amplifier and its current feed means in series between the second one of said operating voltage terminals and the end of said current-sensing element which is nearest in the circuit to said flash lamps.
Claim 9
Dependent Claim
70 words
A circuit as claimed in claim 6, in which said means connecting the collector electrode of each sequencing transistor to the gate electrode of the succeeding SCR comprises a plurality of gating transistors each having a base electrode connected to the collector electrode of the preceding sequencing transistor, and a collector electrode and an emitter electrode respectively connected to a current electrode and the gate electrode of the succeeding SCR.
Claim 10
Dependent Claim
87 words
A circuit as claimed in claim 8, in which each of said sequencing circuit stages further includes a lock-out transistor having a collector electrode connected to said base electrode of the gating transistor, an emitter electrode connected to a point of reference potential, and a base electrode, said circuit further including means for producing a lock-out signal in response to the flashing of one of said flash lamps, and electrical means connected to apply said lock-out signal to all of said base electrodes of the lock-out transistors.
Claim 11
Dependent Claim
123 words
A circuit as claimed in claim 9, in which said amplifier in the compensator circuit comprises electrical means connecting a first end of said current feed means to a first one of said operating voltage terminals, a pair of series-connected resistors connected at one end thereof to the second end of said current feed means, electrical means connecting the other end of said pair of resistors to the second one of said operating voltage terminals, and a transistor having a base electrode connected to the junction of said pair of resistors, a collector electrode connected to said second end of the current feed means, and electrical means connecting the emitter electrode of said transistor to said second one of the operating voltage terminals.
Claim 12
Dependent Claim
69 words
A circuit as claimed in claim 10, including a current-sensing element connected in a current path between said flash lamps and said first one of the operating voltage terminals, and electrical means connecting said amplifier and its current feed means in series between said second one of the operating voltage terminals and the end of said current sensing element which is nearest in the circuit to said flash lamps.
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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) | 1978-02-03 | 1978-08-05 | 1979-02-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-03 | 1982-08-05 | 1983-02-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-03 | 1986-08-05 | 1987-02-04 | $7700.00 | Window Closed / Lapsed |