Samsung KCT52A, Training Manual

Page: 59 / 93

KCT52A Chassis
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SAMSUNG GROUP
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Vertical Deflection Circuit Description
IC301 TDA8450Q(25/27Inch Only)
PIN Description
TDA8350Q TDA8356 Description
Pin 1, 2 Pin 1, 2 Input Power Stage
Pin 3 Pin 9 Feedback Voltage
Pin 4 Pin 3 Operating Supply Voltage
Pin 5, 9 Pin 4, 7
Def. Current Outputs in Opposite Phase
Pin 8 Pin 6 Flyback Supply Voltage
Pin 10 Pin 8 Guard Output
Pin 11,12,13 EastWest Amp for pincushion correction
Circuit Descriptions
The vertical driver circuits a bridge configuration. The deflection coil is
connected between the outputs of both output amplifiers, which are dri-
ven in opposite phase. The resistor (R303 for TDA356; R307, R308 for
TDA8350Q) in series with the deflection coil and the voltage across this
resistor is internally used for feedback information.
The input circuit is voltage driven, and is adapted for circuits which
deliver symmetrical signal currents. The differential current across the
external resistor (R301) a voltage which determines the output current
through the coil. The relation between the differential current through
this resistor and the output current is : Idiff * R301 - Icoil * (R303 or
R307/308). The output current can be adjusted by varying the resistor
R301.
The flyback voltage is determined by the additional supply voltage from
46V line.
The guard circuit output can be used for blanking the screen during
short of the output circuit, or of the supply voltage. However, for this
chassis this is not used.