The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 01, 1988
Filed:
Mar. 09, 1987
Hans-Jurgen Fahnrich, Munich, DE;
Walter Hirschmann, Munich, DE;
Abstract
To suppress introduction of harmonics into the power supply network of a high-frequency operated fluorescent lamp, an input capacitor (C2) connected across a direct current supply (P1, P2) for a transistor push-pull high-frequency circuit--operating at between 25-50 kHz--has a pair of serially connected diodes (D4, D5) connected thereto. The junction point (M2) of the diodes is connected via a coupling capacity (C7) to a common junction (M1) of the push-pull connected transistors (T1, T2). The power line circuit has a line choke (L2, L2') connected, either in advance or behind a rectifier (G1) supplying direct current to the transistor push-pull circuit. The circuit effectively suppresses harmonics, particularly the third harmonic, without introducing additional losses in the circuit, especially if a further capacitor (C8) is connected in the resonance circuit of the fluorescent lamp and to the diode junction (M2) between the two diodes (D4, D5).