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. 07, 1999
Filed:
Dec. 19, 1997
Alan E Brown, Georgetown, TX (US);
Dell USA, L.P., Round Rock, TX (US);
Abstract
A discharge control circuit for a power supply switching converter that, in response to a cessation of current from an AC power source, makes conductive a main switching element of the switching converter to discharge the bulk filter capacitor through the main switching element to a charge level that meets safety standards. The discharge control unit includes a current limiting circuit for limiting the discharge current through the main switching element in which the rate of rise of the discharge current is controlled with the use of an RC circuit. The discharge control unit also includes a state machine that activates the current limiting circuit in response to a cessation of the modulation mode of the switching converter. The discharge control circuit also includes a reset circuit for placing the state machine in a known state during the startup of the switching converter.