(19)
(11) EP 0 379 729 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
19.12.1990 Bulletin 1990/51

(43) Date of publication A2:
01.08.1990 Bulletin 1990/31

(21) Application number: 89123995.6

(22) Date of filing: 27.12.1989
(51) International Patent Classification (IPC)5: H05B 41/29
(84) Designated Contracting States:
DE ES FR GB

(30) Priority: 25.01.1989 IT 1918789

(71) Applicants:
  • Tacconi, Renato
    I-20033 Desio Milan (IT)
  • Tacconi, Fulvio
    I-20033 Desio Milan (IT)

(72) Inventors:
  • Tacconi, Renato
    I-20033 Desio Milan (IT)
  • Tacconi, Fulvio
    I-20033 Desio Milan (IT)

(74) Representative: Luksch, Giorgio, Dr.-Ing. et al
Ing. A. Giambrocono & C. S.r.l. Via Rosolino Pilo, 19/b
20129 Milano
20129 Milano (IT)


(56) References cited: : 
   
       


    (54) Improvements in frequency converter circuits for powering cold cathode fluorescent tubes


    (57) A frequency converter circuit for powering cold cathode fluorescent tubes comprising a circuit block (1) generating a square wave pulsed signal. This signal is used to power the primary winding (2) of a transformer (3) the secondary (4) of which is connected to at least one cold cathode fluorescent tube, said primary winding being connected to components (58, 63) connected to said circuit block (1), and which zero the mean value of said square wave pulsed signal.







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