US3978390A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dc-ac inverter for supplying a discharge lamp
Assignee: US Philips Corp
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Filing: 1975-06-24
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Granted: 1976-08-31
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Expires: 1995-06-24
Abstract
Abstract A relaxation circuit effects the drive of a blocking invertor for supplying a discharge lamp, thus enabling this invertor to operate in a wide range of the electric input voltage while the whole arrangement has a high efficiency.
Inventors
- 👤 Michel Remery
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 14:07
CPC Classifications
H; H02; H02M; H02M7/00; H02M7/42; H02M7/44; H02M7/48; H02M7/53; H02M7/537; H05; H05B; H05B41/00; H05B41/14; H05B41/26; H05B41/28; H05B41/282; H05B41/285; H05B41/2851; H05B41/2855
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
141 words
A DC-AC invertor for supplying a discharge tube comprising, a first transistor connected to a transformer having at least a primary winding, a secondary winding and a coupling winding, means connecting the base electrode of the first transistor via a first threshold element to the junction of a resistor and a capacitor which are connected in a series circuit having a small time constant, means connecting said series circuit between DC supply conductors of the invertor, means connecting the collector of the first transistor via a second threshold element to a control electrode of a bistable auxiliary circuit having an output electrode connected via an auxiliary transistor to the base of the first transistor, means connecting a second capacitor between said control electrode of the auxiliary circuit and a conductor which connects the emitters of two transistors of said auxiliary circuit.
Claim 2
Dependent Claim
141 words
A DC-AC invertor for supplying a discharge tube comprising, a first transistor connected to a transformer having at least a primary winding, a secondary winding and a coupling winding, means connecting the base electrode of the first transistor via a first threshold element to the junction of a resistor and a capacitor which are connected in a series circuit having a small time constant, means connecting said series circuit between DC supply conductors of the invertor, means connecting the collector of the first transistor via a second threshold element to a control electrode of a bistable auxiliary circuit having an output electrode connected via an auxiliary transistor to the base of the first transistor, means connecting a second capacitor between said control electrode of the auxiliary circuit and a conductor which connects the emitters of two transistors of said auxiliary circuit.
Claim 3
Dependent Claim
18 words
An invertor as claimed in claim 1, characterized in that the second threshold element comprises a Zener diode.
Claim 4
Dependent Claim
38 words
An invertor as claimed in claim 2 comprising means connecting one of the electrodes of the Zener diode to a voltage divider which is formed by resistors connected between the collector and the emitter of the first transistor.
Claim 5
Dependent Claim
68 words
An invertor as claimed in claim 1 further comprising, means connecting the collector of said first transistor to one of said DC supply conductors via said primary winding and the emitter of the first transistor to the other one of said DC supply conductors, means connecting the coupling winding between the base and emitter of the first transistor, and means connecting the secondary winding to the discharge tube.
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) | 1979-08-31 | 1980-03-01 | 1980-08-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-08-31 | 1984-03-01 | 1984-08-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-08-31 | 1988-03-01 | 1988-08-31 | $7700.00 | Window Closed / Lapsed |