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:
Oct. 26, 1999
Filed:
Aug. 05, 1998
Robert William Kruppa, Cary, NC (US);
Jeffrey Paul Rutigliano, Raleigh, NC (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
This apparatus and method controls and limits the flow of in-rush current and maintains a supply voltage to a peripheral device during power surges. The apparatus and method essentially isolate and limit in-rush current flow to an in-rush circuit comprising a capacitive load and series resistor connected directly to the power bus at one end and to a reference potential at the other end. A switching device is coupled to the series resistor. A current sensing circuit is coupled to the series resistor. During initial start-up or 'hot plugging' of the device, a control circuit turns 'off' the switching device causing the load to be charged from the power bus through the resistive device for a pre-selected time interval, after which the switching circuit is turned 'on' to bypass the resistive device and connect the load and the peripheral device to the power bus. The current sensing circuit detects when current flow is out of the load at which time the sensing circuit send a discharge signal to turn on the switching circuit and bypass the resistor which maintains the supply voltage of the device during the power surge.