Toshiba CN27E90 Technical Training Manual page 90

4-1. Basic Operation and Current Path
4-1-1. Later Half Scanning Period
When the power is turned on, the power supply voltage VB
is applied to Cs and Csm, and the Cs acts as a power source
for a later half of the scanning period for which the H. OUT
transistor is turned on, and the deflection current Iy flows in
the path as shown below
H.OUT
D
M
Fig. 12-9
Voltage & current waveform in H period.
I 0
Y
V
A
0
I
M
0
I
DC
V
0
B
Fig. 12-10
V
A
FBT
L
DY
lP
I
Y
+
Cs
V
B
V
B
L
M
I
M
I
DC
C
SM
+
4-1-2. First Half Scanning Period
When the base drive current decreases and the H. OUT
transistor is turned off, each energy stored in LDY, Lm, Lp
of FTB is transferred to C1, C2 and C3, respectively, and the
resonant current becomes zero at a center of the flyback
period. Then, VA and VB pulses show a maximum amplitude.
I
P1
0
I
Y
V
A
0
I
0
M
I
DC
V
0
B
C
1
C 0
2
C
0
3
90
V
A
L
DY
I
Y
C C
1 2
I
Y2
I
P2 Cs
V
B
L
M
I
M
C
Fig. 12-11
C : I +I
1 Y1 P1
C : I +I
2 Y2 P2
- -
C : I I I
3 P2 Y1 M
Fig. 12-12
FBT
lP
V
B
I
DC
SM