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:
May. 26, 1998
Filed:
Jan. 11, 1996
John Joseph Carey, Raleigh, NC (US);
Raymond Mathew Clemo, Raleigh, NC (US);
Carleton David Driscoll, Cary, NC (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A hot-plugging circuit associated with a backplane or motherboard for controlling the rate of application of voltage and current to a non-operating printed-circuit card in the process of being inserted into a backplane connector in a system including other already-operating printed-circuit cards. Each backplane connector has connector contacts of two different lengths. An isolation diode at each connector is connected to two of the longer contacts of the connector and is forward biased by a non-operating printed-circuit card being inserted into that connector. The forward-biased isolation diode triggers a card insertion circuit to recognize that a non-operating printed-circuit card is in the process of being inserted. The card insertion circuit triggers a voltage and current control circuit to ramp up the voltage and current furnished to the non-operating printed circuit. The card insertion circuit also triggers a timeout circuit which, in the case of a printed-circuit card which draws a high current, terminates the operation of the control circuit after a time period during which the printed-circuit board should normally have been inserted, if the card is angled too much upon insertion and can not be fully inserted. Completion of insertion of the printed-circuit card makes electrical connection to shorter contacts which carry the normal voltage supply to the printed-circuit card and disables the control circuit.