Hi Joe,
I don't know the answer for sure but I'd think it might.

Do you have any other filtering on the power supply input side to choke=20
the 50Hz ?

Peter

On 04/03/2015 3:58 PM, IVP wrote:
> Hi all,
>
> I've got 3V3 / 5V micros and an audio board
>
> For a particular reason I'm using a 12V AC wall wart. Regulating
> down to 3V3 and 5V is not a problem, but I want to keep as
> much of the voltage from the AC as I can, at least over 12VDC.
>
> The audio section seems particularly sensitive to hum. I've tried
> adding more and more reservoir caps, up to 10,000uF, but the
> hum is still quite noticeable
>
> With the original 1000uF I started with, as the circuit draws only
> 250mA, there's about 2Vp-p of 50Hz ripple on ~ 14VDC
>
> If I take a switching IC, something like an MC34063, and use
> the rough DC as the input do you think the IC will chop it up
> enough and re-assemble it to remove the ripple completely ?
>
> Intuitively I think it will, and would try it if I wasn't a little presse=
d
> for time, rather than asking
>
> TIA
>
> Joe
>
--=20
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