Caple C702G Manuel de service télécharger pdf (Page 136)

8-11

MAX. MIN.

C519 WAVE

TILT

LEFT/RIGHT

CORNER

BTM BALANCE

CORNER

TOP BALANCE

IMAGEIMAGE

OSM MENU

C519 WAVE

(Fig.2.8) Voltage at C519 and screen image

3) Horizontal Drive Circuit

The horizontal drive system uses what is generally referred to as a flyback system.

The horizontal drive pulse output from IC501 pin 25 switches Q555 on and off.

It is amplified by T551 and switches Q561 (the horizontal output transistor) on and off.

The voltage of C552 for horizontal drive is fixed at 15V.

4) Horizontal Deflection Output Circuit

It corrects the optimum horizontal linearity by using Linear-coil and S correction capacitor to change the

horizontal frequency mode. Horizontal frequency mode is shown in CPU CIRCUIT description section.

The Inductance of Linear-coil (T571) varies with horizontal frequency.

①

Variable Linearity Coil (T571)

Horizontal circuit has variable linearity coil (T571) and control the character to optimum in all resolution.

The value of T571 is changed by current of control coil and ambient circuit. The current goes down at

the lower frequency and goes up at the higher frequency due to change the base voltage of Q571.

Base voltage is adjusted to optimum by H.LINEARITY1 and H.LINEARITY2 as following.

Q571 H.LINEARITY2

Base

H.LINEARITY1

31KHz 60KHz 106KHz

Horizontal Frequency

②

S-Correction Circuit

IC571 (I/O Expander) make the matrix of FH band, and it switches a FET array (MQ571).

*Matrix of FH band (Refer to Fig. 6-1)

1 2 ... 131 132 133 134 135 136 137 138 139 140 141 ... 285 286

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Caple C702G Manuel de service Page 136