Samsung LW32A23W, Service Manual

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Block Diagrams
LW32A23W/LW40A23W
6. RTFC Terminal
Adjustment should be performed while checking the actual operation in the range of 100k to 1 M.During
an IC examination, you may sometimes find minimum oscillating frequency at the RTFC resistor, but as
the secondary circuit performs feedback control, Id determined by ton at RTFC shows changes in the
peak value due to the primary inductance lp of the transistor and the winding ratio. If the load
consumed by the secondary circuit is constant, the peak value of Id increases and the frequency
decreases as lp becomes smaller and the ton setting becomes larger.
7. Phase Correction
When you have an unusual type of secondary feedback circuit and
load specifications, if the phase correction of the error amp on the
secondary circuit is not sufficient, due to the capacity of the
smoothing input condenser being too small and the ripple voltage
being too high, you can get a good result by adding a condenser
between the FB/OLP terminal of W6800 and S/GND. The FB/OLP
terminal is fitted with latch delay CR.If R is small, it may improve
the shift start during startup,but may also cause extreme delay.
Therefore ,care should be taken to avoid excessive response in
changing the loads.