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. 06, 2001
Filed:
Feb. 25, 2000
Mitchell A. Markow, Spring, TX (US);
Stephen K. Gustafson, Cypress, TX (US);
Compaq Computer Corporation, Houston, TX (US);
Abstract
A high voltage flyback power supply provides slope-based primary feedback to control the off-time of the power supply. When a negative slope is detected at a low side of a primary winding of the power supply, an off-time cycle is terminated and a next on-time cycle is initiated. The slope-based off-time primary feedback helps to keep the off-time of the power supply in sync with ringing of the primary leakage inductance and the primary-side capacitance of the power supply. Such a power supply is particularly useful for battery-powered systems with low voltage rails. The power supply can also include on-time feedback to shorten the on-time of the power supply after the secondary-side voltage rises beyond a certain relatively high voltage level. In this way, the transformer of the power supply is charged less when the power supply is driving relatively light loads.