Electronics > Repair
Giant MLCC cap in CCFL HV supply, what could be its capacitance?
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…
Navigation
[0] Message Index
[*] Previous page
Go to full version