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, 1997
Filed:
Sep. 30, 1994
Kian P Hoh, Singapore, SG;
Chun H Wu, Singapore, SG;
Thomson Consumer Electronics, S.A., Courbevoie, FR;
Abstract
In a switch mode power supply of a video apparatus, a capacitor develops a supply voltage that is coupled to a main current conducting electrode of a driver transistor. The driver transistor drives a switching power transistor. An arrangement charges the charging capacitor when the video apparatus operates in standby mode. A delay circuit introduces a delay time between a time when the capacitor begins to be charged and the time when a switching control signal is applied to the driver transistor for operation in a run mode. Consequently, the capacitor develops sufficient voltage that insures sufficient base current to turn on the power transistor in to saturation prior to the time the switching control signal is applied to the driver transistor. Thus, a possible damage to the power transistor is prevented.