Author Topic: 3Vpp switching noise on switchmode bench PSU  (Read 1193 times)

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Offline king.oslo

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3Vpp switching noise on switchmode bench PSU
« on: June 14, 2013, 12:10:11 pm »
Hello there,

I've got a XHR-150-7 150V 7AMP PSU. Recently I noticed some serious 3Vpp switching noise on the output. Think I will pop it open in a few days to check for problems. What is the common corporate causing problems like these?

Thanks.

Kind regards,
Marius
 

Offline Paul Price

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Re: 3Vpp switching noise on switchmode bench PSU
« Reply #1 on: June 14, 2013, 12:50:33 pm »
Large valued electrolytic capacitors (directly at the output? or HV mains post rectifier?  have developed high ESR, outgassing or open. Look for the dead cap signature: any sign of the tops being domed shaped, bulging...should be perfectly flat in a healthy electrolytic.
« Last Edit: June 14, 2013, 12:53:59 pm by Paul Price »
 

Offline David_AVD

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Re: 3Vpp switching noise on switchmode bench PSU
« Reply #2 on: June 14, 2013, 10:04:35 pm »
Also make sure that you're really measuring that noise on the output.  Dave did a video recently where the signal shown on the scope was actually induced by another switch-mode power supply that was running nearby.
 


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