| Electronics > Repair |
| Giant MLCC cap in CCFL HV supply, what could be its capacitance? |
| << < (3/3) |
| floobydust:
CCFL inverters typically have a HV ceramic cap across the tube(s), at the output side of the transformer. Check for any. They would make acoustic noise. |
| inse:
In the photo in reply #5, there is none… |
| floobydust:
Yes I don't see one unless it's on the bottom side. Hard to follow traces to see if it's Royer or not, or figure out who makes the transformer. I know high voltages on MLCC makes noise but it should be above 20kHz say? If the noise is intolerable, I'd change it over to LED backlighting I think. |
| inse:
Perhaps it’s not the switching frequency that causes the noise but the superimposed dimming. I would expect a lower dimming frequency but my knowledge on this is a couple of years old (~20) but the car is not that fresh as well… |
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