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:
Mar. 07, 2000
Filed:
May. 26, 1998
U.S. Philips Corporation, New York, NY (US);
Abstract
A battery-powered electrical device comprising a switchable voltage drain (3,5) and a rechargeable battery (1), and further comprising means for measuring the voltage V across the terminals of the battery (1) as a function of cumulative discharge time t, and for determining the cumulative discharge time t.sub.p corresponding to the attainment of the local extremum of least magnitude in the derivative dV/dt. In a particular embodiment, the device contains means for interrupting the voltage drain (3,5) upon expiry of a cumulative discharge time t.sub.e =nt.sub.p, whereby n is a fixed, pre-selected real number. In addition, it is possible to calculate and display the remaining discharge time t.sub.rem =m.sub.o t.sub.o -t, where m.sub.o is a fixed, pre-selected real number. The values of n and m.sub.o will generally be chosen to lie in the range 1.2-6.