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A PUSH-PULL HORIZONTAL DEFLECTION STAGE

IP.com Disclosure Number: IPCOM000024136D
Original Publication Date: 1979-Oct-31
Included in the Prior Art Database: 2004-Apr-02
Document File: 2 page(s) / 299K

Publishing Venue

Xerox Disclosure Journal

Abstract

The conventional circuit used in the horizontal section of raster..scanned CRT display systems is shown in Figure 1 where L1 is the inductance of the horizontal coil of the deflection yoke, and D is the drive signal. Analysis of this well-known circuit shows that current and voltage waveforms of Figure 2 will be generated and

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Page 1 of 2

XEROX DISCLOSURE JOURNAL

A PUSft~PULLHORIZONTAL DEFLECTION

~TSTAGE Carlo Infante

Proposed Classification
U.S. Cl. 313/421

mt. Cl. HOIj 29/70

Th~

Dl

01

V

FIG, I

p

VF

~Il

FIG, 4

V

FIG. 2

FIG.

Volume 4 Number 5 September/October 1979 635

[This page contains 1 picture or other non-text object]

Page 2 of 2

A PUSH-~PULLHORIZONTAL DEFLECTION OUTPUT STAGE (Cont'd)

The conventional circuit used in the horizontal section of raster..scanned CRT display systems is shown in Figure 1 where L

                                1 is the inductance of the horizontal coil of the deflection yoke, and D is the drive signal. Analysis of this well~~known circuit shows that current and voltage waveforms of Figure 2 will be generated and

that the following relationships will hold:

~

= ~ ~ L~i~

As the system resolution increases, both T and TR must decrease since more (horizontal) scanning lines per frame mus~ be generated. Consequently, as resolution is increased, both i and VF are seen to increase. This is also due to the

fact that L

        1 must decrease seas to make the self~resonant yoke frequency higher. As a result, the voltage and current ratings required from transistor increase to the point that transistors with the required characteristics are either not available

or are extremely expensive.

The following concept discloses a circuit configuration in which the above limitations are overcome. This is accomplished by driving the horizontal coil with two transistors instead of one. This can be carried out in either of two...