US3700956A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Arc discharge lamp control circuit
Assignee: Verizon Laboratories Inc
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Filing: 1971-01-04
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Granted: 1972-10-24
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Expires: 1991-01-04
Abstract
Abstract A high-frequency, lightweight, solid-state ac ballast for operating arc discharge lamps such as fluorescent lamps. An ac ballast in accordance with the invention includes a single transistor and a storage capacitor interconnected with a lightweight air-gap ferrite core transformer provide a blocking oscillator circuit capable of high-frequency ac operation. To initiate operation of the blocking oscillator circuit, lowfrequency (e.g., 50-60 hertz) ac input voltage signals are converted to a dc voltage and applied to a starting circuit for producing a voltage for charging the storage capacitor. When the voltage developed across the capacitor reaches a predetermined value, the transistor is forward biased into conduction thereby initiating operation of the blocking oscillator circuit. After a predetermined period of time, the transistor is reversed biased by a voltage produced across a regenerative feedback winding of the air-gap transformer thereby terminating operation of the blocking oscillator circuit. During the operation of the blocking oscillator circuit through several cycles, high-frequency ac voltage signals (e.g., 20 kilohertz) are produced across a load winding of the air-gap transformer for operating a pair of fluorescent lamps. A modified version of the abovedescribed ac ballast includes a square hysteresis loop ferrite toroid in the blocking oscillator circuit, in addition to the air-gap transformer, for causing the transistor to switch more quickly between its conducting and nonconducting states.
Inventors
- 👤 Ronald D Cluett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 18:40
CPC Classifications
H; H05; H05B; H05B41/00; H05B41/14; H05B41/26; H05B41/28; H05B41/282; H05B41/2821; H05B41/2822; Y; Y10; Y10S; Y10S315/00; Y10S315/07
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
349 words
A control circuit for operating an arc discharge lamp, comprising: input terminal means adapted to receive an ac input voltage signal; converter means coupled to the input terminal means and operative to convert the ac input voltage signal received at the input terminal means to a dc voltage signal; starting means coupled to the converter means and operative in response to the dc voltage signal to produce a control voltage; and oscillator circuit means, said oscillator circuit means comprising: a transistor including a base, an emitter and a collector and having a conducting condition and a non-conducting condition; impedance means coupled to the starting means and to the transistor, said impedance means including a capacitance; and transformer means coupled to the transistor and to the arc discharge lamp; said transformer means including a ferrite toroid having a primary winding and a secondary winding, one end of the secondary winding being connected to the base of the transistor and the other end being connected to the emitter of the transistor through the capacitance; and an air-gap transformer having a primary winding in series with the collector of the translator, a feedback secondary winding having one end thereof connected to one end of the primary winding of the ferrite toroid and the other end thereof connected to the other end of the primary winding of the ferrite toroid, and a load secondary winding coupled to the arc discharge lamp; said transformer means being operative when the transistor is initially operating in its conducting condition to cause the transistoR to operate more fully in its conducting condition and, when the transistor is operating more fully in its conducting condition, to then cause the transistor to operate in its non-conducting condition, said transformer means being further operative while the transistor is successively operating in its conducting and non-conducting conditions to produce an ac operating voltage signal for operating the arc discharge lamp; said impedance means being operative in response to the control voltage produced by the starting means to develop a voltage thereacross for initiating operation of the transistor in its conducting condition.
Claim 2
Dependent Claim
349 words
A control circuit for operating an arc discharge lamp, comprising: input terminal means adapted to receive an ac input voltage signal; converter means coupled to the input terminal means and operative to convert the ac input voltage signal received at the input terminal means to a dc voltage signal; starting means coupled to the converter means and operative in response to the dc voltage signal to produce a control voltage; and oscillator circuit means, said oscillator circuit means comprising: a transistor including a base, an emitter and a collector and having a conducting condition and a non-conducting condition; impedance means coupled to the starting means and to the transistor, said impedance means including a capacitance; and transformer means coupled to the transistor and to the arc discharge lamp; said transformer means including a ferrite toroid having a primary winding and a secondary winding, one end of the secondary winding being connected to the base of the transistor and the other end being connected to the emitter of the transistor through the capacitance; and an air-gap transformer having a primary winding in series with the collector of the translator, a feedback secondary winding having one end thereof connected to one end of the primary winding of the ferrite toroid and the other end thereof connected to the other end of the primary winding of the ferrite toroid, and a load secondary winding coupled to the arc discharge lamp; said transformer means being operative when the transistor is initially operating in its conducting condition to cause the transistoR to operate more fully in its conducting condition and, when the transistor is operating more fully in its conducting condition, to then cause the transistor to operate in its non-conducting condition, said transformer means being further operative while the transistor is successively operating in its conducting and non-conducting conditions to produce an ac operating voltage signal for operating the arc discharge lamp; said impedance means being operative in response to the control voltage produced by the starting means to develop a voltage thereacross for initiating operation of the transistor in its conducting condition.
Claim 3
Dependent Claim
17 words
A control circuit in accordance with claim 1 wherein the arc discharge lamp is a fluorescent lamp.
Claim 4
Dependent Claim
235 words
An ac ballast for operating an arc discharge lamp comprising: input terminal means adapted to receive an ac input voltage signal; full-wave rectifier means coupled to the input terminal means for rectifying the ac input voltage signal received at the input terminal means; a filter capacitance coupled to the full-wave rectifier means for filtering the full-wave rectified voltage signal produced by the full-wave rectifier means to produce a dc voltage signal; a starting circuit connected in parallel with the filter capacitance and comprising a series arrangement of a resistance and a diode; and an oscillator circuit comprising: a storage capacitance connected in parallel with the diode; a transistor having a base, an emitter, and a collector; a ferrite toroid having a primary winding and a secondary winding, one end of the secondary winding being connected to the base of the transistor and the other end being connected to the emitter of the transistor through the capacitance; and an air-gap transformer, said air-gap transformer having a primary winding connected between the collector of the transistor and the resistance included in the starting circuit, a regenerative feedback secondary winding having one end thereof connected to one end of the primary winding of the ferrite toroid and the other end thereof connected to the other end of the primary winding of the ferrite toroid, and a load secondary winding adapted to be connected to the arc discharge lamp.
Claim 5
Dependent Claim
235 words
An ac ballast for operating an arc discharge lamp comprising: input terminal means adapted to receive an ac input voltage signal; full-wave rectifier means coupled to the input terminal means for rectifying the ac input voltage signal received at the input terminal means; a filter capacitance coupled to the full-wave rectifier means for filtering the full-wave rectified voltage signal produced by the full-wave rectifier means to produce a dc voltage signal; a starting circuit connected in parallel with the filter capacitance and comprising a series arrangement of a resistance and a diode; and an oscillator circuit comprising: a storage capacitance connected in parallel with the diode; a transistor having a base, an emitter, and a collector; a ferrite toroid having a primary winding and a secondary winding, one end of the secondary winding being connected to the base of the transistor and the other end being connected to the emitter of the transistor through the capacitance; and an air-gap transformer, said air-gap transformer having a primary winding connected between the collector of the transistor and the resistance included in the starting circuit, a regenerative feedback secondary winding having one end thereof connected to one end of the primary winding of the ferrite toroid and the other end thereof connected to the other end of the primary winding of the ferrite toroid, and a load secondary winding adapted to be connected to the arc discharge lamp.
Claim 6
Dependent Claim
24 words
A ballast in accordance with claim 3 further comprising a ballasting capacitance connected in series with the load secondary winding of the air-gap transformer.
Claim 7
Dependent Claim
22 words
A ballast in accordance with claim 4 further comprising a bypass capacitance connected between the collector and the emitter of the transistor.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-24 | 1976-04-24 | 1976-10-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-24 | 1980-04-24 | 1980-10-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-24 | 1984-04-24 | 1984-10-24 | $7700.00 | Window Closed / Lapsed |