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:
Mar. 06, 1990
Filed:
Jun. 09, 1988
RCA Licensing Corporation, Princeton, NJ (US);
Abstract
A MOSFET power switching transistor in a DC-to-DC converter of a television apparatus has a drain electrode that is coupled via a primary winding of a chopper transformer to an input supply voltage. A first signal at a given frequency causes, during normal operation, alternate conduction and nonconduction in the transistor. A second signal is generated that is proportional to the voltage developed across the internal 'on' resistance of the transistor when the transistor is conductive. The second signal is clamped when the MOSFET transistor is nonconductive. The second signal is coupled via a current sensing arrangement to the transistor gate. The second signal prevents the transistor from further conducting when the amplitude of the second signal exceeds a predetermined value that corresponds with a predetermined limiting threshold level of current in the transistor.