9-3
6. t4 ~ t6:
For this period, C0 is charged with the deflection current
having opposite polarity to that of the deflection current
stated in “3.”, and when the resonant capacitor voltage
exceeds Vcc, the damper diode D conducts. The deflection
current decreases along to an exponential function
(approximately linear) curve and reaches zero at t6. Here,
operation returns to the state described under “1”, and the one
period of the horizontal scanning completes. For this period
a left half of the screen is scanned.
In this way, in the horizontal deflection scanning, a current
flowing through the damper diode scans the left halfof the
screen; the current developed by the horizontal output
transistor scans the right half of the screen; and for the
flyback period, both the damper diode and the output transistor
are cut off and the oscillation current of the circuit is used.
Using the oscillation current improves efficiency of the
circuit. That is, about a half of deflection current (one fourth
in terms of power) is sufficient for the horizontal output
transistor.
TR
base voltage
TR
base current
TR
collector
current
D
damper
current
(SW2)
Swirch
current
(TR, SW1)
Resonant
capacitor
current
(Co)
Deflection
current
(L)
TR
collector
voltage
A
0
t1 t2 t3 t4 t5 t6
B
0
0
C
D
0
0
0
E
0
F
G
H
Fig. 3
To Next Page
Loading...
