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Horizontal Deflection Circuit

IP.com Disclosure Number: IPCOM000050483D
Original Publication Date: 1982-Nov-01
Included in the Prior Art Database: 2005-Feb-10
Document File: 2 page(s) / 65K

Publishing Venue

IBM

Related People

Yamaguchi, H: AUTHOR

Abstract

A conventional horizontal deflection circuit cannot control both horizontal deflection yoke current and anode voltage when the anode current changes. The present horizontal deflection circuit includes a high voltage regulation circuit to keep the anode voltage constant. Further, an additional inductor is provided to permit control of the horizontal deflection yoke current independent of the high voltage regulation, whereby both the yoke current and the anode voltage can be controlled to provide a constant screen size.

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Horizontal Deflection Circuit

A conventional horizontal deflection circuit cannot control both horizontal deflection yoke current and anode voltage when the anode current changes. The present horizontal deflection circuit includes a high voltage regulation circuit to keep the anode voltage constant. Further, an additional inductor is provided to permit control of the horizontal deflection yoke current independent of the high voltage regulation, whereby both the yoke current and the anode voltage can be controlled to provide a constant screen size.

Fig. 1 shows a conventional horizontal deflection circuit. Current through a deflection yoke L1 is controlled by a voltags regulator 10 responsive to an H (horizontal) width control circuit 12 which detects voltage variations at the collector of transistor Q1. A problem of the conventional circuit is poor stability of the anode voltage, Which results in screen size variations.

Fig. 2 shows a new horizontal deflection circuit which is characterized by the provision of a voltage regulator 20, a high voltage control circuit 22, and an inductor L2.

The high voltage control circuit 22 detects variations in the anode voltage to control the voltage regulator 20 so as to keep the anode voltage constant. For example, when the anode current increases and thus the anode voltage decreases, the voltage regulator 20 acts to increase the anode voltage.

However, there arises then a problem that the voltage regulation also causes an inc...