Lead-lag, series-sequence starting and operating apparatus for three to six fluorescent lamps

• US 4,006,384 A
• Filed: 01/06/1976
• Issued: 02/01/1977
• Est. Priority Date: 01/06/1976
• Status: Expired due to Term

• Current Assignee: Cooper Industries, Inc. (Eaton Corporation PLC.)
• Original Assignee: Westinghouse Electric Company LLC (Brookfield Asset Management Incorporated)
• Inventors: Elms, Robert T., Engel, Joseph C.
• Primary Examiner(s): La Roche, Eugene
• Application Number:
  US05/646,795
• Time in Patent Office: 392 Days
• Field of Search: 315/227 R, 315/246, 315/247, 315/250, 315/253, 315/254, 315/312, 315/323, 315/324, 315/DIG. 5
• US Class Current: 315/323
• CPC Class Codes: H05B 41/2325 provided with pre-heating electrodes
• CPC Class Codes: Y10S 315/05 Starting and operating circuit for fluorescent lamp

Abstract

Lead-lag, series-sequence starting and operating apparatus for three to six fluorescent lamps comprises two parallel circuit branches, one of which comprises a ballast capacitor and two lamps in series for a three or four lamp apparatus or three lamps in series for a five or six lamp apparatus. The other circuit branch comprises an inductor ballast and one or two lamps in series for a three or four lamp apparatus and two or three lamps in series for a five or six lamp apparatus. An additional ballast inductor connects in series with the two parallel-connected circuits and the AC power source. Starting capacitors parallel individual lamps and means are provided for preheating the lamp electrode coils upon energization of the apparatus. In operation, the lamp electrode coils are all preheated and the lamps which are ballasted by the capacitor, which constitutes the lead circuit, then sequentially start. The ballast capacitor and the additional ballast inductor constitute a circuit which is at least partially resonant at the line frequency and the resulting increased potential drop across the operating lead circuit sequentially initiates the discharge in the lamps which are in series with the first inductor, which constitutes the lag circuit. When all lamps are operating, the electrode coil heating potential is decreased to minimize power losses. For a four lamp circuit, the cost of the apparatus is considerably less than the cost of two two-lamp rapid start ballasts which are presently used for most installations, and the power losses in the present ballast are also considerably reduced.

Claims

1. Apparatus for starting and operating from an AC source of predetermined frequency and potential three, four, five or six low-pressure, positive-column elongated discharge lamp means each having electrode coils connected to an individual double contact member affixed to each end of each said elongated discharge lamp means, said apparatus comprising:

a. two parallel circuit branches connected across two common circuit points in said apparatus, one of said circuit branches comprising a first inductor means and from one to three pairs of output terminal means across which the double contact members of some of said lamp means are adapted to be connected, with said first inductor means and said lamp means as connected in said one circuit branch being in series-circuit relationship, the other of said circuit branches comprising ballast capacitor means and from one to three pairs of output terminal means across which the double contact members of the remainder of said lamp means are adapted to be connected, with said ballast capacitor means and said lamp means as connected in said other circuit branch being in series-circuit relationship, said output terminal means in at least one of said circuit branches comprising two or three pairs of series-connected output terminals, each said pair of output terminals adapted to have the double contact members of one of said lamp means connected thereacross, and starting capacitor means connected in parallel with a portion of said series-connected output terminals sequentially to apply the available starting potential across each individual pair of said series-connected output terminals upon energization of said apparatus thereby to sequentially start said lamp means as connected thereacross;

b. input terminals adapted to be connected to said AC source of predetermined frequency and potential, second inductor ballast means connected between one of said input terminals and one of said common circuit points in said apparatus, the other of said common circuit points in said apparatus connected to the other of said input terminals, and said ballast capacitor means and said second inductor ballast means at said AC source predetermined frequency comprising a circuit which is at least partially resonant; and

c. means for applying a small predetermined lamp electrode coil preheating potential to said output terminal means upon energization of said apparatus.

2. Apparatus for starting and operating from an AC source of predetermined line frequency and potential three or four low-pressure, positive-column elongated discharge lamp means each having electrode coils connected to an individual double contact member affixed to each end of each said elongated discharge lamp means, said apparatus comprising:

a. two parallel circuit branches connected across two common circuit points in said apparatus, one of said circuit branches comprising first inductor means and one or two pairs of output terminal means across which the double contact members of some of said lamp means are adapted to be connected, with said first inductor means and said lamp means as connected in said one circuit branch being in series-circuit relationship, the other of said circuit branches comprising ballast capacitor means and two pairs of output terminal means across which the double contact members of the remainder of said lamp means are adapted to be connected, with said ballast capacitor means and said lamp means as connected in said other circuit branch being in series-circuit relationship, and starting capacitor means connected across one pair of each said series-connected two pairs of output terminal means;

b. input terminals adapted to be connected to said AC source of predetermined frequency and potential, second inductor ballast means connected between one of said input terminals and one of said common circuit points in said apparatus, the other of said common circuit points in said apparatus connected to the other of said input terminals, and said ballast capacitor means and said second inductor ballast means at said AC source predetermined frequency comprising a circuit which is at least partially resonant; and

c. means for applying a small predetermined lamp electrode coil preheating potential to said output terminal means upon energization of said apparatus.

3. The apparatus as specified in claim 2, wherein after said lamp means are started, said small electrode coil preheating potential as applied to said output terminal means is substantially lowered to decrease power consumption in said apparatus.

4. The apparatus as specified in claim 3, wherein said means for applying a small predetermined lamp electrode coil preheating potential to said output terminal means comprises an electrode coil transformer having a primary winding and multiple secondary windings, said primary winding connects across said two common circuit points in said apparatus, and said secondary windings connect to individual ones of said output terminal means.

5. The apparatus as specified in claim 3, wherein said means for applying a small predetermined lamp electrode coil preheating potential to said output terminal means comprises multiple small coils connected in transformer relationship to said first inductor means, said multiple small coils are connected to individual ones of said output terminal means, and a switching circuit connects across said common circuit points in said apparatus to conduct only during the period when said lamp means in said one circuit branch are not operating to cause said coil preheating potential to be applied to said output terminal means.

6. The multilamp starting and operating apparatus as specified in claim 2, wherein said ballast capacitor means and said second inductor ballast means which comprise said circuit which is at least partially resonant have such relative reactance values with respect to said AC source predetermined frequency that the maximum voltage developed across said other circuit branch during both starting and operation of said lamp means exceeds said predetermined potential of said AC source.

7. The multilamp starting and operating apparatus as specified in claim 6, wherein said AC source is rated at 480 VAC and 60 Hz.

8. The multilamp starting and operating apparatus as specified in claim 6, wherein said AC source is rated at 277 VAC and 60 Hz.

9. The apparatus for starting and operating lamp means as specified in claim 8, wherein each of said circuit branches has two pairs of output terminal means, said lamps as adapted to be connected to said output terminal means are four fluorescent lamps of 40 watt rating, and one pair of each of said two pairs of output terminal means is paralleled by a starting capacitor.

10. The apparatus as specified in claim 9, wherein said lamps are of a T10 design.

11. The apparatus as specified in claim 9, wherein said lamps are of a T12 design.

12. The apparatus as specified in claim 11, wherein said 40WT12 fluorescent lamps are of a straight-tube design.

13. Apparatus for starting and operating from an AC source of predetermined line frequency and potential five or six low-pressure, positive-column elongated discharge lamp means each having electrode coils connected to an individual double contact member affixed to each end of each said elongated discharge lamp means, said apparatus comprising:

a. two parallel circuit branches connected across two common circuit points in said apparatus, one of said circuit branches comprising a first inductor means and two or three pairs of output terminal means across which the double contact members of some of said lamp means are adapted to be connected, with said first inductor means and said lamp means as connected in said one circuit branch being in series-circuit relationship, the other of said circuit branches comprising ballast capacitor means and three pairs of output terminal means across which the double contact members of the remainder of said lamp means are adapted to be connected, with said ballast capacitor means and said lamp means as connected in said other circuit branch being in series-circuit relationship, and starting capacitor means connected in parallel with a portion of said series-connected output terminal means sequentially to apply the available starting potential across each individual pair of said series-connected output terminal means upon energization of said apparatus thereby to sequentially start said lamp means as connected thereacross;

b. input terminals adapted to be connected to an AC source of said predetermined frequency and potential, second inductor ballast means connected between one of said input terminals and one of said common circuit points in said apparatus, the other of said common circuit points in said apparatus connected to the other of said input terminals, and said ballast capacitor means and said second inductor ballast means at said AC source predetermined frequency comprising a circuit which is at least partially resonant; and

c. means for applying a small predetermined lamp electrode coil preheating potential to said output terminal means upon energization of said apparatus.

14. The multilamp starting and operating apparatus as specified in claim 13, wherein said ballast capacitor means and said second inductor ballast means which comprise said circuit which is at least partially resonant have such relative reactance values with respect to said AC source predetermined frequency that the maximum voltage developed across said other circuit branch during both starting and operation of said lamp means exceeds said predetermined potential of said AC source.

15. The multilamp starting and operating apparatus as specified in claim 14, wherein said AC source is rated at 480 VAC and 60 Hz.

16. The apparatus as specified in claim 13, wherein after said lamp means are started, said small electrode coil preheating potential as applied to said output terminal means is substantially lowered to decrease power consumption in said apparatus.

17. The apparatus as specified in claim 16, wherein said means for applying a small predetermined lamp electrode coil preheating potential to said output terminal means comprises an electrode coil transformer having a primary winding and multiple secondary windings, said primary winding connects across said two common circuit points in said apparatus, and said secondary windings connect to individual ones of said output terminal means.

18. The apparatus as specified in claim 16, wherein said means for applying a small predetermined lamp electrode coil preheating potential to said output terminal means comprises multiple small coils connected in transformer relationship to said first inductor means, said multiple small coils are connected to individual ones of said output terminal means, and a switching circuit connects across said common circuit points in said apparatus to conduct only during the period when said lamp means in said one circuit branch are not operating to cause said coil preheating potential to be applied to said output terminal means.

19. The apparatus as specified in claim 13, wherein each three pairs of output terminal means in said circuit branches have a first individual starting capacitor connected in parallel with two of said pairs of output terminal means, and an additional individual starting capacitor connects in parallel with one of the pairs of said output terminal means which is paralleled by said first starting capacitor.

20. The apparatus as specified in claim 19, wherein each said circuit branch has three pairs of said output terminal means therein.