Dynamic Convergence Correction Circuit - NEC MultiSync FP1350 Service Manual

9. DYNAMIC CONVERGENCE CORRECTION CIRCUIT

The dynamic convergence is corrected by adjusting the DC,saw wave and parabolic wave current flowing at
both (the horizontal and vertical convergence correction) coils which are constructed on the deflection
yoke.(refer to Fig.9.1.)
The horizontal convergence correction circuit is same as the vertical convergence correction, the horizontal
correction circuit being described below.
The convergence correction wave is generated by DSP(IC501).IC501 generates the DC, vertical saw wave
and parabolic wave accordiong to calculation based on MPU data and outputs dynamic convergence
correction signal at IC501 pin 61. This signal is integrated at integration circuit composed of R543 and C523.
The output voltage of IC510 (0V-3.3V) generates the convergence correction current which turn the direction
at the center voltage (1.65V). This current flows to the feedback resistors (R8H3), and is detected as voltage
at the feedback resistors. This voltage is fed back to IC8H1.
IC501
61
SERVICE MENU
1 H.S.CONVER
2 V.S.CONVER
3 H.CONVER SAW T
4 H.CONVER PARA T
I1V
IC510
R543
C523
+5V
Fig.9.1. Convergence circuit
USER MENU
HORIZONTAL
VERICAL
TOP HORIZONTAL
-
R8H2
IC8H1
R8H1
1.4V
IC8H1
R8JA
R8JC
WAVE FORM
DC
DC
1V
1V
8-51
R8H6
H_CONVER
R8H5
R8H3
IC8H2
PICTURE IMAGE
BGR