Efficient power transfer in electronic ballast

Abstract

An electronic ballast for one or more F32T8 or F25T8 or F1718 fluorescent lamps has a new design tool for efficient transfer of power to the lamp or the lamps. The design tool is constructed from the ballast DC voltage and the commercially available lamp specifications by the manufacturers or from the American National Standards (ANSI). This design tool is shown below. F × C = K 2 ⁢ W 2 V 1 2 - V 0 2 R 0 2 2 ⁢   ⁢ π ⁢   ⁢ V 1 where W=Lamp rating in watts, V 0 =Lamp voltage. V 1 =Electronic Ballast DC voltage, R 0 =Lamp Impedance in ohms, (ANSI C78.1-1991). k=Empirical constant=1.5 to 10.0.

1. A ballast for coupling to at one fluorescent lamp comprising:
 a) circuitry means coupled to a source of alternating current for generating a sine wave having a frequency F;    b) at least one capacitor having a capacitance C coupled in parallel to a corresponding one of said at one fluorescent lamp and to said circuitry means, such that F and C satisfy the equation: 
         F   ×   C     =               K   2     ⁢     W   2         V   1   2       -       V   0   2       R   0   2             2   ⁢     xV   1             
   where W=specified wattage of the lamp    V 1 =applied DC voltage of the ballast    V 0 =a predetermined lamp voltage    R 0 =a predetermined lamp impedance    K=empirical constant in the range of 1.5-10.0.    
     
     
       2. A ballast for coupling to at least two fluorescent lamps comprising:
 a) circuitry means coupled to a source of alternating current for generating a sine wave having a frequency F;    b) a plurality of capacitors having a capacitance C, each coupled in parallel to a corresponding one of said at least two fluorescent lamps and to said circuitry means, such that F and C satisfy the equation: 
         F   ×   C     =               K   2     ⁢     W   2         V   1   2       -       V   0   2       R   0   2             2   ⁢     xV   1             
   where W=specified wattage of the lamp    V 1 =applied DC voltage of the ballast    V 0 =a predetermined lamp voltage    R 0 =a predetermined lamp impedance    K=empirical constant in the range of 1.5-10.0,    wherein one end of each of said capacitors is coupled to a first terminal at a first end of its corresponding fluorescent lamp, and a second end of each of said capacitors is coupled to a first terminal at a second end of its corresponding fluorescent lamp, and a second terminal at said second end of said corresponding fluorescent lamp is coupled to a corresponding second terminal of a second end of an adjacent one of said at least two fluorescent lamps.    
     
     
       3. A ballast for coupling to at least one F 32 T 8  fluorescent lamp comprising:
   a )  circuitry means coupled to a source of alternating current for generating a sine wave having a frequency F;        b )  at least one capacitor having a capacitance C coupled in parallel to a corresponding one of said at least one F 32 T 8  fluorescent lamp and to said circuitry means, such that F in hertz and C in farads satisfy an equation:            F   ×   C     =               K   2     ⁢     W   2         V   1   2       -       V   0   2       R   0   2             2   ⁢           ⁢   π   ⁢           ⁢     V   1                 where W=specified wattage of the lamp in watts,        V   1   =applied DC voltage of the ballast in volts,        V   0   =a predetermined lamp voltage in volts,        R   0   =a predetermined lamp impedance in ohms,        K=empirical constant in a range of  1 . 5 - 10 . 0 .       
     
     
       4. The ballast of  claim 3  wherein the alternating current is generated by switching transistors. 
     
     
       5. The ballast of  claim 3  wherein the ballast does not include an input transformer. 
     
     
       6. The ballast of  claim 3  wherein the ballast does not include an output transformer. 
     
     
       7. The ballast of  claim 3  wherein the ballast does not include an input or an output transformer. 
     
     
       8. The ballast of  claim 3  wherein the ballast includes a boost regulator inductor. 
     
     
       9. The ballast of  claim 3  wherein the ballast includes a common mode choke. 
     
     
       10. A ballast for coupling to at least one F 25 T 8  fluorescent lamp comprising:
   a )  circuitry means coupled to a source of alternating current for generating a sine wave having a frequency F;        b )  at least one capacitor having a capacitance C coupled in parallel to a corresponding one of said at least one F 25 T 8  fluorescent lamp and to said circuitry means, such that F in hertz and C in farads satisfy an equation:            F   ×   C     =               K   2     ⁢     W   2         V   1   2       -       V   0   2       R   0   2             2   ⁢           ⁢   π   ⁢           ⁢     V   1                 where W=specified wattage of the lamp in watts,        V   1   =applied DC voltage of the ballast in volts,        V   0   =a predetermined lamp voltage in volts,        R   0   =a predetermined lamp impedance in ohms,        K=empirical constant in a range of  1 . 5 - 10 . 0 .       
     
     
       11. The ballast of  claim 10  wherein the alternating current is generated by switching transistors. 
     
     
       12. The ballast of  claim 10  wherein the ballast does not include an input transformer. 
     
     
       13. The ballast of  claim 10  wherein the ballast does not include an output transformer. 
     
     
       14. The ballast of  claim 10  wherein the ballast does not include an input or an output transformer. 
     
     
       15. The ballast of  claim 10  wherein the ballast includes a boost regulator inductor. 
     
     
       16. A ballast for coupling to at least one F 17 T 8  fluorescent lamp comprising:
   a )  circuitry means coupled to a source of alternating current for generating a sine wave having a frequency F;        b )  at least one capacitor having a capacitance C coupled in parallel to a corresponding one of said at least one F 17 T 8  fluorescent lamp and to said circuitry means, such that F in hertz and C in farads satisfy an equation:            F   ×   C     =               K   2     ⁢     W   2         V   1   2       -       V   0   2       R   0   2             2   ⁢           ⁢   π   ⁢           ⁢     V   1                 where W=specified wattage of the lamp in watts,        V   1   =applied DC voltage of the ballast in volts,        V   0   =a predetermined lamp voltage in volts,        R   0   =a predetermined lamp impedance in ohms,        K=empirical constant in a range of  1 . 5 - 10 . 0 .       
     
     
       17. The ballast of  claim 16  wherein the alternating current is generated by switching transistors. 
     
     
       18. The ballast of  claim 16  wherein the ballast does not include an input transformer. 
     
     
       19. The ballast of  claim 16  wherein the ballast does not include an output transformer. 
     
     
       20. The ballast of  claim 16  wherein the ballast does not include an input or an output transformer. 
     
     
       21. The ballast of  claim 16  wherein the ballast includes a boost regulator inductor. 
     
     
       22. The ballast of  claim 16  wherein the ballast includes a common mode choke. 
     
     
       23. The ballast of  claim 16  wherein the ballast includes a common mode choke. 
     
     
       24. A fluorescent lighting system comprising:
   a. at least one F 32 T 8  fluorescent lamp; and        b. a ballast coupled to said at least one F 32 T 8  fluorescent lamp comprising:        1   )  circuitry means coupled to a source of alternating current for generating a sine wave having a frequency F;          2   )  at least one capacitor having a capacitance C coupled in parallel to a corresponding one of said at least one F 32 T 8  fluorescent lamp and to said circuitry means, such that F in hertz and C in farads satisfy an equation:            F   ×   C     =               K   2     ⁢     W   2         V   1   2       -       V   0   2       R   0   2             2   ⁢           ⁢   π   ⁢           ⁢     V   1                 where W=specified wattage of the lamp in watts,        V   1   =applied DC voltage of the ballast in volts,        V   0   =a predetermined lamp voltage in volts,        R   0   =a predetermined lamp impedance in ohms,        K=empirical constant in a range of  1 . 5 - 10 . 0 .         
     
     
       25. A fluorescent lighting system comprising:
   a. at least one F 25 T 8  fluorescent lamp; and        b. a ballast coupled to said at least one F 25 T 8  fluorescent lamp comprising:        1   )  circuitry means coupled to a source of alternating current for generating a sine wave having a frequency F;          2   )  at least one capacitor having a capacitance C coupled in parallel to a corresponding one of said at least one F 25 T 8  fluorescent lamp and to said circuitry means, such that F in hertz and C in farads satisfy an equation:            F   ×   C     =               K   2     ⁢     W   2         V   1   2       -       V   0   2       R   0   2             2   ⁢           ⁢   π   ⁢           ⁢     V   1                 where W=specified wattage of the lamp in watts,        V   1   =applied DC voltage of the ballast in volts,        V   0   =a predetermined lamp voltage in volts,        R   0   =a predetermined lamp impedance in ohms,        K=empirical constant in a range of  1 . 5 - 10 . 0 .         
     
     
       26. A fluorescent lighting system comprising:
   a. at least one F 17 T 8  fluorescent lamp; and        b. a ballast coupled to said at least one F 17 T 8  fluorescent lamp consisting:        1   )  circuitry means coupled to a source of alternating current for generating a sine wave having a frequency F;          2   )  at least one capacitor having a capacitance C coupled in parallel to a corresponding one of said at least one F 17 T 8  fluorescent lamp and to said circuitry means, such that F in hertz and C in farads satisfy an equation:            F   ×   C     =               K   2     ⁢     W   2         V   1   2       -       V   0   2       R   0   2             2   ⁢           ⁢   π   ⁢           ⁢     V   1                 where W=specified wattage of the lamp in watts,        V   1   =applied DC voltage of the ballast in volts,        V   0   =a predetermined lamp voltage in volts.        R   0   =a predetermined lamp impedance in ohms,        K=empirical constant in a range of  1.5-10.0.