Patent US3792309A successfully refreshed from Google Patents.
US3792309A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Strobe light intensity control
Assignee: Multi Electric Mfg Inc
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Filing: 1972-08-30
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Granted: 1974-02-12
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Expires: 1992-08-30
Abstract
Abstract A strobe light circuit in which the light intensity of the strobe lamp is varied by adding or removing selected flash capacitors in circuit with the lamp to increase or decrease surge current through the lamp. The circuit connection between each of the flash capacitors and the strobe lamp is controlled by a double-pole, double-throw relay with a normally open relay contact in series with the flash capacitor to enable it to charge and discharge and a normally closed contact across the flash capacitor to discharge it when it is not being used to provide a portion of the surge current. Both contacts are connected at the low side of the power line to minimize electrical arcing and are mechanically linked together such that the conducting set of contacts always breaks contact before the nonconducting set of contacts closes. Intensity control switches are provided to energize the relay coils for the selected capacitors. One flash capacitor is always connected across the strobe lamp to maintain a minimum light intensity, and this capacitor is discharged through a normally closed relay contact when power for the entire circuit is interrupted.
Inventors
- 👤 C Mcdonald
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 14:41
CPC Classifications
H; H05; H05B; H05B41/00; H05B41/14; H05B41/30; H05B41/34
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
283 words
In a strobe light circuit having a source of power, a strobe lamp connected across said source of power, and means for repetitively firing said lamp, said lamp flashing when fired with a light intensity directly related to the magnitude of surge current therethrough, intensity control means for varying the light intensity of said lamp, comprising: capacitor means connected with the source of power and said lamp for providing at least a portion of said surge current; and switching means including first switch means connected in series with the capacitor means across the lamp and source of power switchable between nonconductive and conductive states, said first switch means when in its conductive state providing a charging path from the power supply to charge the capacitor and also providing a discharge path from the capacitor to the lamp when the lamp is fired to provide a portion of said surge current thereto, said first switch means when in its nonconductive state removing said charging and discharging paths to prevent the capacitor from applying a portion of said surge current to the lamp; second switch menas connected across said capacitor means and switchable between non-conductive and conductive states, to enable said capacitor to charge from said source of power when in the non-conductive state and to dissipate any charge on said capacitor when in the conductive state, said second switch means being normally in a state opposite to that of said first switch means; and means for actuating said switch means between states, the conductive one of said first and second switch means switching to its non-conductive state prior to the non-conductive one of said first and second switch means switching to its conductive state.
Claim 2
Dependent Claim
283 words
In a strobe light circuit having a source of power, a strobe lamp connected across said source of power, and means for repetitively firing said lamp, said lamp flashing when fired with a light intensity directly related to the magnitude of surge current therethrough, intensity control means for varying the light intensity of said lamp, comprising: capacitor means connected with the source of power and said lamp for providing at least a portion of said surge current; and switching means including first switch means connected in series with the capacitor means across the lamp and source of power switchable between nonconductive and conductive states, said first switch means when in its conductive state providing a charging path from the power supply to charge the capacitor and also providing a discharge path from the capacitor to the lamp when the lamp is fired to provide a portion of said surge current thereto, said first switch means when in its nonconductive state removing said charging and discharging paths to prevent the capacitor from applying a portion of said surge current to the lamp; second switch menas connected across said capacitor means and switchable between non-conductive and conductive states, to enable said capacitor to charge from said source of power when in the non-conductive state and to dissipate any charge on said capacitor when in the conductive state, said second switch means being normally in a state opposite to that of said first switch means; and means for actuating said switch means between states, the conductive one of said first and second switch means switching to its non-conductive state prior to the non-conductive one of said first and second switch means switching to its conductive state.
Claim 3
Dependent Claim
18 words
The light intensity control means of claim 1, including means providing a switch signal for said switch means.
Claim 4
Dependent Claim
28 words
The light intensity control means of claim 2, in which both of said switch means are controlled by relay coil means connected with said switch signal providing means.
Claim 5
Dependent Claim
25 words
The light intensity control of claim 3, in which said relay coil means comprises a single relay coil for controlling both of said switch means.
Claim 6
Dependent Claim
42 words
The light intensity control means of claim 1, in which said first and second switch means comprise mechanical switch contacts, none of the contacts of either of said switch means being common to the contacts of the other of said switch means.
Claim 7
Dependent Claim
83 words
The light intensity control means of claim 1, in which said capacitor Means comprises a plurality of capacitors connected in parallel with each other, and said switching means comprises a corresponding plurality of pairs of first and second switches connected with said plurality of capacitors, respectively, each of said plurality of pairs of first and second switches selectively controlling the connection between said lamp and the capacitor to which it is connected, whereby the light intensity of said lamp may be selectively varied.
Claim 8
Dependent Claim
52 words
The light intensity control means of claim 1, in which said power source has a low voltage terminal at a reference potential and a high voltage terminal at other than said reference potential, and said first switch means is connected between said low voltage terminal and one side of said capacitor means.
Claim 9
Dependent Claim
72 words
The light intensity control means of claim 7, in which said second switch means is connected at one side thereof to the junction between the capacitor and the first switch means and connected at the other side thereof through an impedance means to the other side of the capacitor, both said other side of the capacitor and said impedance means being connected to the high voltage terminal of said source of power.
Claim 10
Dependent Claim
35 words
The light intensity control of claim 1 including a bleeder resistor in series with said second switch means for dissipating any charge on said capacitor when said second switch means is in its conductive state.
References Cited (Backward Citations)
US3267328A
Cited
US3414765A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-11 | 1977-08-13 | 1978-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-11 | 1981-08-13 | 1982-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-11 | 1985-08-13 | 1986-02-12 | $7700.00 | Window Closed / Lapsed |