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. 17, 2015
Filed:
Mar. 18, 2010
Toshiaki Nakamura, Kodama, JP;
Toshiaki Nakamura, Kodama, JP;
Abstract
A discharge lamp ballast includes a DC-DC converter circuit configured to convert a voltage of a DC power supply by a switching operation of a switching element based on a PWM signal and to output a DC power, an inverter circuit configured to invert the DC power into an AC power, and a PWM ON-width control circuit configured to control switching conditions of the switching element in the DC-DC converter circuit immediately before a polarity of the AC power is reversed such that an ON-width of the PWM signal is increased from a start of a polarity reversal so as to increase the DC power in a predetermined period. The polarity of the AC power of the inverter circuit is reversed in synchronism with a switching timing of the switching element immediately after the control by the PWM ON-width control circuit to increase the ON-width.