[sdiy] Quick Question about Grounding Power Supplies

[Shawn Rakestraw]

Thanks for the answers. Looks like I may have opened a sensitive topic. I
guess with a 10 ohm resistor and cap it is pretty near the same as straight
connected. What is the purpose of the resistor? Is it to act as a fuse in
case of short?

On Fri, Jul 3, 2020 at 3:53 PM Michael E Caloroso <mec.forumreader at gmail.com>
wrote:

> Never connect earth to the CT of a transformer.
>
> At least here in the US, earth of a three prong AC plug should be
> connected to the metal chassis.  Local circuit ground should be
> coupled to earth through a low resistance (IE 10ohm at least 1/2 watt)
> with a cap in parallel.  That would be a better solution to reducing
> noise.
>
> MC
>
> On 7/3/20, Shawn Rakestraw <shawnrakestraw at gmail.com> wrote:
> > Some of you may remember helping me learn how to design some PCBs a few
> > months back. I have been using one of my homemade eurorack cases for a
> > while now. To refresh the idea, it is essentially an electronotes design
> > where a 24V center tapped transformer is regulated down to +12V and -12V.
> >
> > My question is this - Should the ground pin of the power cord be
> connected
> > to the center tap of the transformer? Currently, I have it connected to
> the
> > "Earth" terminal of the power switch and it is also connected to the
> "Body"
> > of the transformer, but I have left the center tap "Floating".
> >
> > After putting a Make Noise Pressure Points module into the case and
> > noticing what looks like a lot of noise on the signal, I think that maybe
> > the earth ground should connect to the center tap and floating ground.
> >
> > Thanks for your advice.
> >
> > - Shawn
> >
>
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