US3553525A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cathode heater arrangement for vacuum type display devices
Assignee: Cooper Industries LLC
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Filing: 1969-05-28
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Granted: 1971-01-05
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Expires: 1989-05-28
Abstract
Abstract A control circuit for controlling the symbols displayed by a plurality of lamp indicators, each having a cathode and a plurality of phosphor-coated anodes. The control circuit is adapted to control the showing of symbols when similar anodes in all the display devices are connected to a common supply conductor. During the showing of any symbol, the electronemitting cathode is temporarily disconnected from its power supply by a series transistor. This type of control circuit is particularly adapted to the showing of digital information provided by a computer circuit. The circuit does not employ resistors which produce excessive heat and power consumption.
Inventors
- 👤 Francis A Mcguirk Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 06:28
CPC Classifications
H; H03; H03K; H03K21/00; H03K21/08
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
179 words
A control circuit for repetitively energizing a plurality of indicator lamps in sequence, said lamps each comprising an electron-emissive cathode filament and a plurality of phosphorescent anodes, said control circuit comprising: a. first circuit means including switching means for sequentially and repetitively applying a predetermined potential to selected groups of anodes in each lamp; b. second circuit means operative to control the flow of filament current and the filament potential, and including: 1. a first semiconductor switching means which normally passes current to the lamp filament to render it electron-emissive and to maintain the filament at a potential substantially equal to the potential of the anode, and 2. second semiconductor switching means operative to control the cathode-to-anodes potential of each indicator lamp; and c. signal control circuit means coupled to both the first and second circuit means and operative to render said first semiconductor switching means nonconductive and simultaneously render said second semiconductor switching means conductive, thereby cutting off the filament current and establishing an electric field between the selected anodes and the filament to create an electron flow.
Claim 2
Dependent Claim
179 words
A control circuit for repetitively energizing a plurality of indicator lamps in sequence, said lamps each comprising an electron-emissive cathode filament and a plurality of phosphorescent anodes, said control circuit comprising: a. first circuit means including switching means for sequentially and repetitively applying a predetermined potential to selected groups of anodes in each lamp; b. second circuit means operative to control the flow of filament current and the filament potential, and including: 1. a first semiconductor switching means which normally passes current to the lamp filament to render it electron-emissive and to maintain the filament at a potential substantially equal to the potential of the anode, and 2. second semiconductor switching means operative to control the cathode-to-anodes potential of each indicator lamp; and c. signal control circuit means coupled to both the first and second circuit means and operative to render said first semiconductor switching means nonconductive and simultaneously render said second semiconductor switching means conductive, thereby cutting off the filament current and establishing an electric field between the selected anodes and the filament to create an electron flow.
Claim 3
Dependent Claim
71 words
second semiconductor switching means operative to control the cathode-to-anodes potential of each indicator lamp; and c. signal control circuit means coupled to both the first and second circuit means and operative to render said first semiconductor switching means nonconductive and simultaneously render said second semiconductor switching means conductive, thereby cutting off the filament current and establishing an electric field between the selected anodes and the filament to create an electron flow.
Claim 4
Dependent Claim
71 words
second semiconductor switching means operative to control the cathode-to-anodes potential of each indicator lamp; and c. signal control circuit means coupled to both the first and second circuit means and operative to render said first semiconductor switching means nonconductive and simultaneously render said second semiconductor switching means conductive, thereby cutting off the filament current and establishing an electric field between the selected anodes and the filament to create an electron flow.
Claim 5
Dependent Claim
32 words
A control circuit according to claim 1 wherein said second circuit means includes a third semiconDuctor switching means and biasing circuitry associated therewith, coupled between said first and second semiconductor switching means.
Claim 6
Dependent Claim
18 words
A control circuit according to claim 2 wherein said first, second and third semiconductor switching means are transistors.
Claim 7
Dependent Claim
48 words
A control circuit according to claim 1 wherein the load terminals of said first semiconductor switching means are connected in series with one side of the filament and the load terminals of said second semiconductor switching means are connected in series with the other side of the filament
Claim 8
Dependent Claim
52 words
A control circuit according to claim 1 wherein said first circuit means, when connected to a source of electrical power, simultaneously energizes identical combinations of anodes in all of said lamps and said second circuit means places an electron-accelerating potential between the filament and the combination of anodes of the selected lamps.
Claim 9
Dependent Claim
40 words
A control circuit according to claim 1 in combination with a plurality of indicator lamps, each lamp comprising an electron-emissive filament and seven phosphor-coated anodes arranged in a figure eight pattern for forming the digits from 0 to 9, inclusive.
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) | 1974-01-04 | 1974-07-06 | 1975-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-04 | 1978-07-06 | 1979-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-04 | 1982-07-06 | 1983-01-05 | $7700.00 | Window Closed / Lapsed |