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:
Dec. 18, 2001
Filed:
Apr. 21, 2000
Soongil Hong, Kyonggi-Do, KR;
Dongil Technology Ltd., Kyonggi-do, KR;
Abstract
A fixed frequency driving circuit of a piezo-ceramic transformer capable of controlling an input voltage. The driving circuit includes a lamp; a PCT(Piezo-Ceramic Transformer) for driving the lamp; a PCT driving circuit for driving the PCT; a voltage doubler rectifier for rectifying an output voltage; a summing & error amplifying circuit for outputting by summing a dimming voltage and the output voltage; a charge pump circuit for maintaining zero voltage switching and reducing the switching loss; a temperature compensated VCO for compensating the temperature characteristics of PCT, and impact, etc. in the neighborhood; a phase detector for comparing the phase of the input and output signal of the PCT; a modulator capable of continuously obtaining an amplitude of a first harmonic frequency component when the input voltage is changed from Vmin to Vmax by controlling a duty ratio provided to a driver connected to the PCT according to the output signals of the phase detector and the summing & error amplifier.