Daewoo DDT-21H9ZZF, Service Manual

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Service Manual CP-099F
As this winding voltage does not increase to the set voltage immediately after the control circuit starts operating, V
IN
starts dropping. However, as this winding voltage reaches the set value before V
IN
voltage drops to the shutdown
voltage (at 11V), the control circuit continues operating (see below V
IN
voltage at start-up). R809 resistor prevents that
V
IN
pin voltage varies according to the secondary side output current.
V
IN
must be set higher than the shutdown voltage (V
IN
(off) = 11V
max
) and lower than the O.V.P. (overvoltage
protection) operating voltage
(V
OVP
= 20.5V
min
)
5-9-2-2 STR-F6654 oscillating operation
7