Vertical Output Circuit Section - Kortek KTN-2001 Service Manual

KORTEK Corporation
KTN-2001/1401
PIN 8 is a protection circuit and operates by detection of feedback current.
Generally it can be used by set-up in the range of 1~8.5V. If abnormal phenomena
happens, then high voltage goes up over about 27KV due to abrupt elevation of voltage,
X-ray is discharged within Brown tube. It is the circuit to prevent this and designed to
stop a circuit by detection of this voltage at IC 301 (TDA 2595) PIN No 8 according to
set-up voltage. PIN 3 is connected to a voltage of 12V line, adjusts and controls DC
voltage, and amount of H-POS varies according to varying amount of V/R.
PIN 4 is a horizontal output terminal and can operate horizontal drive stage with this
output. PIN 15 is a terminal to supply Vcc voltage. PIN 14 H-POS adjusts and controls
with DC voltage, and circuit is composed of C308, R309, R308 and VR302.

6-6 VERTICAL OUTPUT CIRCUIT SECTION

As IC 201 is built-in with oscillating part within chip, it has a function of its own oscillation,
amplification and output, and it is designed to operate independently. Besides it is an
independent circuit having special functions of ESD protection, thermal shutdown
protection and etc.
TDA 1675 is a device used to supply to deflection yoke by oscillation and amplification of
the oscillating part built-in within chip, and send output by amplification with pin No 1.
When IC 201 PIN 1 is not supplied with SYNC from outside, it receives input of serrated
wave generated by determination of pulse width according to integer of TDA 1675 PIN 3,
4, 6. Then it is amplified through amplifier built-in within chip and is supplied to deflection
yoke by its output. It is thus composed so that it performs free running motion in this
sequence.
19