Electronic ballast for fluorescent lamp

(19)

(11)

EP 0 831 677 A3

(12)	EUROPEAN PATENT APPLICATION

(88)	Date of publication A3:
	14.10.1998 Bulletin 1998/42

(43)	Date of publication A2:
	25.03.1998 Bulletin 1998/13

(21)	Application number: 97304183.3

(22)	Date of filing: 16.06.1997

(51)	International Patent Classification (IPC)⁶: H05B 41/29

(84)	Designated Contracting States:
	AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE
	Designated Extension States:
	AL LT LV SI

(30)

Priority:

24.09.1996 CN 96119956

(71)	Applicant: MASS TECHNOLOGY (H.K.) LTD.
	Tsimshatsui, Kowloon (HK)

(72)	Inventor:
	Foo, Onn Fah Tsimshatsui, Kowloon, Hong Kong (CN)

(74)	Representative: SERJEANTS
	25, The Crescent King Street Leicester, LE1 6RX Leicester, LE1 6RX (GB)

(54)	Electronic ballast for fluorescent lamp

(57) An electronic ballast for a fluorescent lamp includes a rectifier circuit (11), a filter circuit (16), a high frequency generating and control circuit (17), a starting circuit (18) for the fluorescent tube and main (14) and auxiliary (13) circuits used to increase the power factor of the ballast and to suppress the harmonic current interference. Because of the introduction of the main and the auxiliary current-uninterrupted circuits, the input curent is continuous and follows the variation with the input voltage and the power factor of the ballast is increased while the post high frequency generating and control circuit tends to be stable in operation. Furthermore, the interference of the harmonic current for the ballast will be suppressed effectively, the contamination to power network will be reduced and the electrical security in operation will be enhanced.

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