Patent US3754160A successfully refreshed from Google Patents.
US3754160A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Four-lamp driver circuit for fluorescent lamps
Assignee: Radiant Industries Inc
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Filing: 1971-10-28
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Granted: 1973-08-21
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Expires: 1991-10-28
Abstract
Abstract A two-transistor, high-frequency, non-saturating inverter for operating four fluorescent lamps connected in a series-parallel arrangement. The inverter is supplied either directly from a DC source, or from an AC source via a full-wave bridge rectifier. Transient supression, power-factor correction, and load-balancing networks are provided. Failure or removal of any one lamp will leave two lamps operating in a fail-safe mode.
Inventors
- 👤 S Jensen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:49
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; Y; Y10; Y10S; Y10S315/00; Y10S315/02; Y10S315/07
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
260 words
Apparatus for energizing a plurality of hot-cathode gaseous-discharge lamps, comprising: rectifier means having a pair of input terminals for receiving operating potential for said apparatus, and having a pair of direct-current output leads; means connected to said output leads for changing the directcurrent therefrom to an alternating current having a frequency which is substantially higher than the frequency of said operating potential applied to said input terminals; a first pair of series-connected lamps; a second pair of series-connected lamps; means connecting one terminal of each of said pairs of lamps in common to one alternating-current output terminal of said current changing means; current dividing means having an input connected to the remaining alternating-current output terminal of said current changing means and having a first output connected to the other terminal of said first pair of series-connected lamps, and a second output connected to the other terminal of said second pair of series-connected lamps, for dividing the current from said current changing means equally between the two pairs of series-connected lamps; said current changing means comprises: a saturating two-transistor inverter; said inverter includes: an autotransformer having a continuous multi-tap winding, one end of said winding corresponding to said one alternatingcurrent output terminal and the Other end of said winding corresponding to said remaining alternating-current output terminal; and first and second resistance-capacitance coupled timing network means, each connected between a corresponding one of said two transistors and said autotransformer, for cyclically transferring conduction between said two transistors at a rate which is independent of variations in the magnetic circuit of said autotransformer.
Claim 2
Dependent Claim
260 words
Apparatus for energizing a plurality of hot-cathode gaseous-discharge lamps, comprising: rectifier means having a pair of input terminals for receiving operating potential for said apparatus, and having a pair of direct-current output leads; means connected to said output leads for changing the directcurrent therefrom to an alternating current having a frequency which is substantially higher than the frequency of said operating potential applied to said input terminals; a first pair of series-connected lamps; a second pair of series-connected lamps; means connecting one terminal of each of said pairs of lamps in common to one alternating-current output terminal of said current changing means; current dividing means having an input connected to the remaining alternating-current output terminal of said current changing means and having a first output connected to the other terminal of said first pair of series-connected lamps, and a second output connected to the other terminal of said second pair of series-connected lamps, for dividing the current from said current changing means equally between the two pairs of series-connected lamps; said current changing means comprises: a saturating two-transistor inverter; said inverter includes: an autotransformer having a continuous multi-tap winding, one end of said winding corresponding to said one alternatingcurrent output terminal and the Other end of said winding corresponding to said remaining alternating-current output terminal; and first and second resistance-capacitance coupled timing network means, each connected between a corresponding one of said two transistors and said autotransformer, for cyclically transferring conduction between said two transistors at a rate which is independent of variations in the magnetic circuit of said autotransformer.
Claim 3
Dependent Claim
39 words
Apparatus as defined in claim 1 including: first and second transient suppression network means, each connected to a corresponding one of said two transistors, for preventing spurious transient voltages from being reflected from said autotransformer to their respective transistors.
Claim 4
Dependent Claim
46 words
Apparatus as defined in claim 1 wherein each of said lamps includes: a pair of spaced-apart heaters; and, said autotransformer includes a plurality of low-voltage windings, inductively coupled to said continuous multi-tap winding, each of which is operatively connected to a corresponding one of said heaters.
Claim 5
Dependent Claim
225 words
Apparatus for energizing a plurality of hot-cathode gaseous-discharge lamps, comprising: rectifier means having a pair of input terminals for receiving operating potential for said apparatus, and having a pair of direct-current output leads; means connected to said output leads for changing the direct-current therefrom to an alternating current having a frequency which is substantially higher than the frequency of said operating potential applied to said input terminals; a first pair of series-connected lamps; a second pair of series-connected lamps; means connecting one terminal of each of said pairs of lamps in common to one alternating-current output terminal of said current changing means; current dividing means having an input connected to the remaining alternating-current output terminal of said current changing means and having a first output connected to the other terminal of said first pair of series-connected lamps, and a second output connected to the other terminal of said second pair of series--connected lamps, for dividing the current from said current changing means equally between the two pairs of series-connected lamps; said current dividing means comprises: first and second windings having a 1:1 ratio and inductively coupled in opposition to a common electromagnetic circuit, one end of each of said windings being connected in common to said current changing means and the remaining ends of said windings being connected to respective pairs of said series-connected lamps.
Claim 6
Dependent Claim
225 words
Apparatus for energizing a plurality of hot-cathode gaseous-discharge lamps, comprising: rectifier means having a pair of input terminals for receiving operating potential for said apparatus, and having a pair of direct-current output leads; means connected to said output leads for changing the direct-current therefrom to an alternating current having a frequency which is substantially higher than the frequency of said operating potential applied to said input terminals; a first pair of series-connected lamps; a second pair of series-connected lamps; means connecting one terminal of each of said pairs of lamps in common to one alternating-current output terminal of said current changing means; current dividing means having an input connected to the remaining alternating-current output terminal of said current changing means and having a first output connected to the other terminal of said first pair of series-connected lamps, and a second output connected to the other terminal of said second pair of series--connected lamps, for dividing the current from said current changing means equally between the two pairs of series-connected lamps; said current dividing means comprises: first and second windings having a 1:1 ratio and inductively coupled in opposition to a common electromagnetic circuit, one end of each of said windings being connected in common to said current changing means and the remaining ends of said windings being connected to respective pairs of said series-connected lamps.
Claim 7
Dependent Claim
30 words
Apparatus as defined in claim 4 wherein said rectifier means comprises: a full-wave diode bridge rectifier, thereby permitting both alternating-current and unpolarized direct-current to properly function as said operating potential.
Claim 8
Dependent Claim
23 words
Apparatus as defined in claim 4 including: capacitive reactance means connected across said remaining ends of said windings of said current dividing means.
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) | 1976-08-20 | 1977-02-19 | 1977-08-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-20 | 1981-02-19 | 1981-08-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-20 | 1985-02-19 | 1985-08-21 | $7700.00 | Window Closed / Lapsed |