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:
Sep. 07, 2004
Filed:
Sep. 26, 2002
Vadim Lubomirsky, Rochester, NY (US);
ENI Technology, Inc., Rochester, NY (US);
Abstract
A power holdup circuit having high power factor during line voltage dropouts is provided in a less complex design. No external monitoring and control is required. A monitoring component of the holdup circuit monitors input voltage to maintain the high power factor. Power from a holdup power source is provided during a line voltage dropout. The circuit is configured to switch to holdup power when a predetermined threshold voltage difference between the power supply and a holdup capacitor is exceeded. The threshold voltage is based upon a voltage rating of a zener diode plus a turn-on voltage of a transistor, which is the switching component of the holdup circuit. The holdup capacitor is precharged to a predetermined level through the diode of the transistor. A power factor of not less than about 0.9 is thereby maintained during line voltage dropouts.