[time-nuts] For those that insist on using switching power supplies

Chris Albertson albertson.chris at gmail.com
Fri Oct 14 14:59:29 EDT 2016

On Fri, Oct 14, 2016 at 11:00 AM, Cube Central <cubecentral at gmail.com> wrote:
> How would one go about testing power supplies and seeing how noisy they are?  I have the standard suite of tools, an oscilloscope and a little (dangerous) know-how.  I am just not sure what to look for or how to safely hook it up to test.

You'd ned a spectrum analyser.    You could assemble one from parts
that are used for Software Radios.   A USB TV tunnel dongle and a
computer and a good mixer and clean oscillator.   With hat you'd be
able to characterize noise from DC to about 900MHz

Those with more money than time would just spend the bucks to buy an SA

Those who don't need numbers would just look at the DC on a scope and
"eye ball it" and say "wow that is noisy" or "wow that looks clean"

In all cases you'd want to put a realistic load on the power supply.
 But what is that? I bet if varies a lot.

And like I wrote before it may not even matter as phones don't
directly use the 5 volt DC that these chargers produce.

Chris Albertson
Redondo Beach, California

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