Len
I am really just a grasshopper but the power supply circuit filters
well and is very stable.
http://www.wagsterstuff.com/photos/pssch.jpghttp://www.wagsterstuff.com/photos/pspeg.jpgThanks for your imput.
Regards
Dennis Waggoner
--- In Homebrew_PCBs@yahoogroups.com, Len Warner <yahoo@...> wrote:
>
> At 15:22 06/02/17, sbdwag wrote:
>
> >f anyone has time please critique my first attempt<snip>
> >Does anything stand out? All comments are appreciated.
> >
> >http://www.wagsterstuff.com/photos/psbd.jpg
> >http://www.wagsterstuff.com/photos/psobj.jpg
>
> I don't mind the layout not being perfectly symmetrical.
>
> What I don't understand is why the negative output is
> a model of good decoupling and the positive output
> is quite the contrary.
>
> On the negative side, capacitors C6, C8 are directly on the
> output track and on a large common ground island.
>
> On the positive side, capacitors C5, C7 are each on a stub
> track off the output track and they are on separate ground areas.
> These are split by the hooked track which runs between the
> pads of both capacitors though there seems no reason why
> it should since there is a direct path available.
>
> Also close to having isolated copper fill islands there too.
>
> As part of this layout style, three tracks seem to run to
> a star point at the diode when what should happen is
> that the output current track visit each decoupling
> capacitor, thus eliminating the stub tracks.
>
> Caps C10, C9 could be closer to their Adjust pins, too.
>
> On the input side reservior caps C1, C2 are on stubs:
> the rectifier output should be taken to the reservior
> then the reservoir to the regulator Input.
>
> Wouldn't hurt to have C3, C4 on the current path too
> but priority is to get them as close as possible to their
> Input pins because they help guarantee regulator stability.
>
> Eliminate stubs, shorten current paths, minimize current loop areas.
>
>
> Regards. Len Warner
>
>
>
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