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:
Apr. 15, 2008
Filed:
Mar. 06, 2006
Ralf Schröder Gen. Berghegger, Glandorf, DE;
Ralf Schröder Gen. Berghegger, Glandorf, DE;
FRIWO Mobile Power GmbH, Ostbevern, DE;
Abstract
The present invention refers to a control circuit and an associated method of controlling the output voltage of a primarily controlled power switching supply with a primary-sided switch and a transformer with an auxiliary winding, in which after opening the primary-sided switch an auxiliary voltage for indicating the output voltage is induced. The induced voltage is supplied to a control circuit as control variable. In order to provide a control circuit, which needs as few external components as possible, which can be manufactured at low cost and which has a possibly low need of space, a driver output of the control circuit is connected to a control input of the primary-sided switch and the control circuit is adapted such that it adjusts the switching frequency of the primary-sided switch depending on the auxiliary voltage, wherein a constant factor of this dependency is selected such that the output current of the switching power supply adopts a predetermined value, and wherein the driver output is further connected to the input of a comparator for determining the current through the primary-sided switch.