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, 2004
Filed:
Feb. 17, 2000
Fong-Jei Lin, Saratoga, CA (US);
Shengbo Zhu, San Jose, CA (US);
Magnex Corp., San Jose, CA (US);
Abstract
A data token with extended operational lifetime incorporates operational circuitry requiring D.C. power, a battery for supplying D.C. power to the circuitry, a power switch coupled between the battery and the circuitry, and a frequency selector for sensing remotely generated signals and for operating the switch when such signals are received so that D.C. power is applied to operate the circuitry only when the remotely generated signals are sensed in order to confine energy drain from the battery to only those periods when circuit operation is needed and extend the useful lifetime and range of the data token. The frequency selector is a crystal having a specific resonant frequency which only responds to remotely generated signals of the matching frequency. The switch is an FET switch. An integrator circuit is coupled between the frequency selector and the FET switch to smooth the D.C. voltage developed by the crystal.