Adjusting strike frequency method by using the voltage and current phase relationship for CCFL, and via the fixed operating frequency converter

• Main Authors: MOYER, JAMES C, RUST, TIMOTHY J
• Format: Patent
• Language: Chinese; English
• Published: 16.04.2005
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS; ELECTRIC HEATING; ELECTRIC LIGHTING NOT OTHERWISE PROVIDED FOR; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; TECHNICAL SUBJECTS COVERED BY FORMER USPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ARTCOLLECTIONS [XRACs] AND DIGESTS

This invention relates to a cold cathode fluorescent lamp (CCFL). By using the voltage and current phase relationship, it adjusts striking frequency of CCFL via the fixed operating frequency converter. It employs a dc-to-ac converter to connect with a primary winding, the frequency of the dc-to-ac converter is controlled by voltage controlled oscillator (VCO). By using a monitoring circuit, it monitors the phase relationship between voltage and current that passing through the primary winding. According to the phase relationship, it adjusts the striking frequency. Finally, it provides the electric power of CCFL to emit light effectively.