US4005335A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High frequency power source for fluorescent lamps and the like
Assignee: CLARK ENGINEERING INC
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Filing: 1975-07-15
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Granted: 1977-01-25
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Expires: 1995-07-15
Abstract
Abstract A power source for operating gas discharge lamps and other loads at high frequency, typically utilizing a 115 volt ac source rectified to provide a 150 volt dc input and providing a 20,000 hertz output. An inverter with a transistor current control for protection against transistor damage under open circuit, starting and no-load conditions, with low power consumption under no-load and with dimming capability. An inverter with a detector circuit connected across the feedback winding or an additional control winding for developing a control signal varying as a function of the feedback winding output, and a zener diode or other device for connecting the control signal to the base of the transistor in current controlling relation when the control signal exceeds a predetermined value.
Inventors
- 👤 Lloyd J. Perper
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 13:30
CPC Classifications
H; H02; H02M; H02M7/00; H02M7/42; H02M7/44; H02M7/48; H02M7/53; H02M7/537; H02M7/5383; H02M7/53846; H02M7/53862; H02M5/00; H02M5/40; H02M5/42; H02M5/44; H02M5/453; H02M5/458; H02M7/53838; H05; H05B; H05B41/00; H05B41/14; H05B41/26; H05B41/28; H05B41/282; H05B41/285; H05B41/2851; H05B41/2855; Y; Y10; Y10S; Y10S315/00; Y10S315/07
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
160 words
In a high frequency power source for a load such as gas discharge lamps, and having an inverter with oscillator circuit and transformer, said transformer having primary, secondary and feedback windings, said oscillator circuit including a transistor having emitter and collector electrodes connected in series with said primary winding across a pair of dc input terminals and having the base and one of said electrodes connected across said feedback winding, the improvement comprising: a detector circuit connected across the transistor output developed at a winding of said transformer for developing a control signal varying as a function of said transistor output; and first means for connecting said control signal to the base of said transistor in parallel with the output of said feedback winding in current controlling relation when said control signal exceeds a predetermined value, said first means including a zener diode and a second diode connected in series in opposing polarity between said detector circuit and transistor base.
Claim 2
Dependent Claim
160 words
In a high frequency power source for a load such as gas discharge lamps, and having an inverter with oscillator circuit and transformer, said transformer having primary, secondary and feedback windings, said oscillator circuit including a transistor having emitter and collector electrodes connected in series with said primary winding across a pair of dc input terminals and having the base and one of said electrodes connected across said feedback winding, the improvement comprising: a detector circuit connected across the transistor output developed at a winding of said transformer for developing a control signal varying as a function of said transistor output; and first means for connecting said control signal to the base of said transistor in parallel with the output of said feedback winding in current controlling relation when said control signal exceeds a predetermined value, said first means including a zener diode and a second diode connected in series in opposing polarity between said detector circuit and transistor base.
Claim 3
Dependent Claim
25 words
A power source as defined in claim 1 wherein said detector circuit includes a rectifier and filter connected across said winding developing said transistor output.
Claim 4
Dependent Claim
31 words
A power source as defined in claim 1 wherein said detector circuit includes a third diode in series with a resistor and capacitor connected across said winding developing said transistor output.
Claim 5
Dependent Claim
18 words
A power source as defined in claim 3 including an additional resistor connected in parallel with said capacitor.
Claim 6
Dependent Claim
19 words
A power source as defined in claim 1 wherein said first means includes means for varying said predetermined value.
Claim 7
Dependent Claim
24 words
A power source as defined in claim 1 wherein said first means includes a dc supply connected between said detector circuit and said base.
Claim 8
Dependent Claim
19 words
A power source as defined in claim 1 including a variable resistor connected in parallel with said zener diode.
Claim 9
Dependent Claim
38 words
A power source as defined in claim 1 wherein said first means includes two zener diodes connected in series between said detector circuit and said base, with a variable resistor connected in parallel with one of said diodes.
Claim 10
Dependent Claim
139 words
In a high frequency power source for a load such as gas discharge lamps, and having an inverter with oscillator circuit and transformer, said transformer having primary, secondary and feedback windings, said oscillator circuit including a transistor having emitter and collector electrodes connected in series with said primary winding across a pair of dc input terminals and having the base and one of said electrodes connected across said feedback winding, the improvement comprising: a control winding on said transformer; a detector circuit connected across said control winding for developing an unaveraged control signal varying as an instantaneous function of the control winding output, said detector circuit including a zener diode and a second diode connected in series in opposing polarity between said control winding and transistor base in current controlling relation when said control signal exceeds a predetermined value.
Claim 11
Dependent Claim
139 words
In a high frequency power source for a load such as gas discharge lamps, and having an inverter with oscillator circuit and transformer, said transformer having primary, secondary and feedback windings, said oscillator circuit including a transistor having emitter and collector electrodes connected in series with said primary winding across a pair of dc input terminals and having the base and one of said electrodes connected across said feedback winding, the improvement comprising: a control winding on said transformer; a detector circuit connected across said control winding for developing an unaveraged control signal varying as an instantaneous function of the control winding output, said detector circuit including a zener diode and a second diode connected in series in opposing polarity between said control winding and transistor base in current controlling relation when said control signal exceeds a predetermined value.
Claim 12
Dependent Claim
18 words
A power source as defined in claim 9 including a resistance connected in parallel with said zener diode.
Claim 13
Dependent Claim
18 words
A power source as defined in claim 9 wherein said resistance is variable for varying the light output.
Claim 14
Dependent Claim
21 words
A power source as defined in claim 9 wherein said resistance includes first and second resistors in series with said diodes.
Claim 15
Dependent Claim
28 words
A power source as defined in claim 9 including a clamping circuit connected across said control winding, and second means for connecting the clamped voltage to said transistor.
Claim 16
Dependent Claim
35 words
A power source as defined in claim 13 wherein said clamping circuit includes a capacitor and a third diode connected at a junction, and said second means includes a zener diode connected at said junction.
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) | 1980-01-25 | 1980-07-26 | 1981-01-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-01-25 | 1984-07-26 | 1985-01-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-01-25 | 1988-07-26 | 1989-01-25 | $7700.00 | Window Closed / Lapsed |