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:
Oct. 26, 2010
Filed:
Nov. 06, 2008
Victor M. Simi, Lexington, KY (US);
Victor M. Simi, Lexington, KY (US);
OSRAM SYLVANIA Inc., Danvers, MA (US);
Abstract
A bias circuit for a switching power supply includes a rectifier that is connected to an AC power source and outputs a full wave rectified voltage Vs; a voltage divider, a diode, a first transistor, and a second transistor connected in parallel between Vs and ground; a capacitor connected between a first terminal of the second transistor and ground; and a node between the capacitor and the first terminal of the second transistor providing an output bias voltage Vcc from the bias circuit. A voltage from the voltage divider is provided to a gate of the first transistor, and the diode and a first terminal of the first transistor are connected to a gate of the second transistor.