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. 06, 1977
Filed:
Jun. 01, 1976
David H Meehan, Chicago, IL (US);
Zenith Radio Corporation, Glenview, IL (US);
Abstract
A television receiver includes a conventional tri-color cathode ray tube display system having horizontal and vertical scansion systems. Conventional signal receiving and processing circuitry recovers picture, sound and scansion synchronizing information. A high voltage detector includes a high pass filter, couples to the horizontal scansion amplifier, differentiating the horizontal retrace pulse to detect both amplitude and duration changes therein. A diode rectifies the derivative signal which is then filtered to produce a high voltage error signal. A PNP, NPN transistor pair configured to form a switch analogous to a silicon controlled rectifier responds to a detected excess of high voltage and loads down the operating supply to the horizontal scansion oscillator to terminate high voltage generation. The transistor pair accommodates a degenerating network to better reject false triggering.