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. 01, 1998
Filed:
Mar. 18, 1997
Arie Ravid, Palo Alto, CA (US);
Abbott Laboratories, Abbott Park, IL (US);
Abstract
A voltage converter and a method for converting AC to DC. A MOSFET (42, 118) conveys current from a full wave rectifier to charge a capacitor (60) that supplies current to a load (64). In a first embodiment, two transistors (32, 34) are connected as a differential pair to control the voltage applied to the gate of the MOSFET, referenced to a zener voltage developed across zener diode (36) that is connected to the emitters of the two transistors. In a second embodiment, a single transistor controls the voltage applied to the gate of the MOSFET, relative to a zener voltage of a zener diode (132). The MOSFET charges the capacitor while the voltage applied to its gate from the rectified signal is greater than the voltage across the capacitor.