Products > Test Equipment
Measuring power supply ripple with Siglent 1202X-E
<< < (8/16) > >>
BillyO:

--- Quote from: nctnico on September 02, 2023, 06:12:09 pm ---What you can try is reverse +/- and see which part of the noise flips up-side-down and what remains the same.

--- End quote ---
Well, grounding one side makes things significantly worse (800mVp-p).  I guess since the PS is already grounded that just created a big loop antenna.

If I reverse things the ripple may indeed reverse, but the spikes are quite random and roughly symmetrical.  They'll look the same anyway.


--- Quote from: nctnico on September 02, 2023, 06:12:09 pm ---It is quite possible the PSU is pushing HF current through the ground connection of the probe
--- End quote ---

BTW, the PSU is being supplied with a ground.  The only way to deal with this properly would be a differential set-up.  Would two probes and the math "-" function work?
dophuc:
You can use an isolation transformer to power the PSU, which ensures the PSU is not grounded. And that's how I do it when testing PSU ripple/noise
tautech:

--- Quote from: dophuc on September 02, 2023, 06:56:32 pm ---You can use an isolation transformer to power the PSU, which ensures the PSU is not grounded. And that's how I do it when testing PSU ripple/noise

--- End quote ---
Any decent PSU output should be isolated from mains Gnd.
BillyO:

--- Quote from: BillyO on September 02, 2023, 06:22:56 pm ---Would two probes and the math "-" function work?

--- End quote ---

Nope!
nctnico:

--- Quote from: tautech on September 02, 2023, 07:04:36 pm ---
--- Quote from: dophuc on September 02, 2023, 06:56:32 pm ---You can use an isolation transformer to power the PSU, which ensures the PSU is not grounded. And that's how I do it when testing PSU ripple/noise

--- End quote ---
Any decent PSU output should be isolated from mains Gnd.

--- End quote ---
Define isolated... You'll still have capacitance towards ground and neutral has a reference to ground as well. Together with the X and Y caps, you have all kinds of ground paths together with capacitive coupling to the surroundings.
Navigation
Message Index
Next page
Previous page
There was an error while thanking
Thanking...

Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod