US3778677A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Inverter ballast circuit
Assignee: Navico Inc
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Filing: 1972-08-25
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Granted: 1973-12-11
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Expires: 1992-08-25
Abstract
Abstract This invention describes a circuit for providing high voltage A.C. potential for the initiation of discharge, and for powering a fluorescent lamp, from a low voltage battery. A principal improvement lies in the use of an additional secondary winding to raise both filaments of the fluorescent lamp to a high voltage A.C. above the ground plane of the battery. This induces ionization inside of the lamp tube by capacitive coupling to the ground plane, and permits more prompt initiation of the discharge in the lamp.
Inventors
- 👤 R Kriege
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 03:50
CPC Classifications
H; H05; H05B; H05B41/00; H05B41/14; H05B41/26; H05B41/28; H05B41/295; H02; H02M; H02M7/00; H02M7/42; H02M7/44; H02M7/48; H02M7/53; H02M7/537; H02M7/5383; H02M7/53832; H02M7/53835; Y; Y10; Y10S; Y10S315/00; Y10S315/05
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
144 words
An inverter-transformer system for a low-wattage fluorescent lamp having two isolated filaments, comprising: a. a D.C. voltage supply; b. a transformer comprising 1. a core having square hysteresis effect, providing saturation at low exciting current; 2. two primary windings; 3. first and second secondary windings of substantially equal voltage; 4. a third secondary winding of voltage approximately twice the voltage of each of said first and second windings; c. transistor flip-flop means connected to said D.C. voltage supply and to said primary windings to provide a high frequency A.C. current to said primary windings; d. said first secondary winding connected between one end of each of said filaments; e. said second secondary winding connected through switch means between the second ends of said filaments; and f. said third secondary winding connected between one end of said first secondary winding and said D.C. power supply.
Claim 2
Dependent Claim
144 words
An inverter-transformer system for a low-wattage fluorescent lamp having two isolated filaments, comprising: a. a D.C. voltage supply; b. a transformer comprising 1. a core having square hysteresis effect, providing saturation at low exciting current; 2. two primary windings; 3. first and second secondary windings of substantially equal voltage; 4. a third secondary winding of voltage approximately twice the voltage of each of said first and second windings; c. transistor flip-flop means connected to said D.C. voltage supply and to said primary windings to provide a high frequency A.C. current to said primary windings; d. said first secondary winding connected between one end of each of said filaments; e. said second secondary winding connected through switch means between the second ends of said filaments; and f. said third secondary winding connected between one end of said first secondary winding and said D.C. power supply.
Claim 3
Dependent Claim
3 words
two primary windings;
Claim 4
Dependent Claim
3 words
two primary windings;
Claim 5
Dependent Claim
21 words
The system as in claim 1 including current limiting means in series with each of said first and second secondary windings.
Claim 6
Dependent Claim
14 words
The system as in claim 1 in which said D.C. supply is a battery.
Claim 7
Dependent Claim
9 words
first and second secondary windings of substantially equal voltage;
Claim 8
Dependent Claim
9 words
first and second secondary windings of substantially equal voltage;
Claim 9
Dependent Claim
94 words
a third secondary winding of voltage approximately twice the voltage of each of said first and second windings; c. transistor flip-flop means connected to said D.C. voltage supply and to said primary windings to provide a high frequency A.C. current to said primary windings; d. said first secondary winding connected between one end of each of said filaments; e. said second secondary winding connected through switch means between the second ends of said filaments; and f. said third secondary winding connected between one end of said first secondary winding and said D.C. power supply.
Claim 10
Dependent Claim
94 words
a third secondary winding of voltage approximately twice the voltage of each of said first and second windings; c. transistor flip-flop means connected to said D.C. voltage supply and to said primary windings to provide a high frequency A.C. current to said primary windings; d. said first secondary winding connected between one end of each of said filaments; e. said second secondary winding connected through switch means between the second ends of said filaments; and f. said third secondary winding connected between one end of said first secondary winding and said D.C. power supply.
Claim 11
Dependent Claim
81 words
The system as in claim 3 including a first and a second transistor, their emitters connected to the negative pole of the battery, their collectors connected to the terminals of a first primary winding, the midpoint of said first primary winding connected through a switch to the positive pole of said battery, the bases of said transistors connected through diodes to the terminals of the second primary winding, the midpoint of said second primary connected through potentiometer means to said battery.
References Cited (Backward Citations)
US2964676A
Cited
US3619713A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-10 | 1977-06-11 | 1977-12-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-10 | 1981-06-11 | 1981-12-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-10 | 1985-06-11 | 1985-12-11 | $7700.00 | Window Closed / Lapsed |