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:
Jan. 08, 2002
Filed:
Nov. 02, 1998
Edward M. Staples, St. Albans, GB;
Gareth E. Allwright, Maulden, GB;
3Com Technologies, Georgetown, KY;
Abstract
A plurality of circuit cards include at least a first card having a first internal power rail, an earth connection, respective operating circuits powered from the first power rail, external terminals coupled to its operating circuit, and a first external connection. A second of the plural cards has a second internal power rail, an earth connection, respective operating circuits powered from the second power rail, external terminals coupled to its operating circuit, and a second external connector. The first card includes a bipolar transistor with an emitter-base junction forwardly biased in response to normal voltage between the first power rail and the earth connection and a collector connected to the first external connector. The second card includes a resistive connection between its second internal power rail and the second external connector and circuits responsive to changes in voltage level at the second connector.