[sdiy] Power Supplies

[Mattias Rickardsson]

On 10 October 2015 at 12:38,  <mskala at ansuz.sooke.bc.ca> wrote:
> On Sat, 10 Oct 2015, Tom Wiltshire wrote:
>> What's the evidence that drawing more current from a linear regulator
>> causes its output voltage to fall? I thought that was exactly the
>> problem regulators were supposed to solve?
>
> If the output voltage doesn't decrease when the current increases, then
> the real part of the regulator's output impedance is zero or negative,
> which is very likely to create stability problems.  You want to to have a
> small, positive, and almost purely resistive output impedance.

Is this the reason why synth power supplies seem to be a little bit off?
Almost all +/- 15 V rails I've measured so far have been something
like +14.9 V and -15.1 V.

/mr