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:
Sep. 14, 1999
Filed:
Jul. 16, 1998
Samson K Toy, Sunnyvale, CA (US);
Cisco Technology, Inc., San Jose, CA (US);
Abstract
A safe external A/C adapter protecting the user against hazardous, high-voltage D/C output. High voltage is defined as any voltage in excess of 60V D/C. The adapter provides an internal remote ON/OFF circuit that automatically switches the D/C output OFF unless the output plug is seated within a mating socket disposed in an electronic device powered by the adapter. When the output plug is so seated, the hazardous voltage output is inaccessible to the user. In addition, a secondary shutdown circuit is provided that latches off the A/C input in the unlikely event that the remote ON/OFF circuit should fail. The secondary shutdown circuit is largely independent from the primary remote ON/OFF circuit, and can be implemented using control circuitry already present in the adapter. No special mechanical connectors are required. Also, because the D/C output is energized only upon insertion of the D/C output plug into the mating socket, and disabled when the output plug is removed, both the electronic device and the user are protected from electric arcing or sparking.