Appendix Service manual WP-795
- 34 -
When the power switch is pushed on, V
IN
increases slowly. During this time, C806 is charged through
R802.
As soon as V
IN
reaches 16V, the STR-F6653 control circuit starts operating. Then, V
IN
is obtained by
smoothing the winding voltage which appears between pin6 and pin7 of the SMPS transformer.
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). R805 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
)
Summary of Contents for DWP-28W2ZLF
Page 11: ...Service manual WP 795 10 3 Circuit Block diagram...
Page 15: ...14 SCHEMATIC DIAGRAM...
Page 16: ...15 EXPLODED VIEW 1 DWP 28W2ZZF 28W2ZLF...
Page 17: ...16 PRINTED CIRCUIT BOARD PCB MAIN...
Page 31: ...Appendix Service manual WP 795 4...
Page 35: ...Appendix Service manual WP 795 8...
Page 48: ...Appendix Service manual WP 795 21 2 Circuit description 2 1 Block diagram...
Page 53: ...Appendix Service manual WP 795 26 Chassis block diagram IF...
Page 57: ...Appendix Service manual WP 795 30 Sound signal flow diagram...
Page 62: ...Appendix Service manual WP 795 35 2 8 2 1 STR F6653 oscillating operation...
