Voltage divider with PS3224

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Audioguy
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Voltage divider with PS3224

Post by Audioguy »

Hi!

I want to use my PS3224 for watching power (+/-20V to +/-100V)amplifier output waveforms and FFT/distortion.

I will use the scope with a laptop running on batteries due to unearthed powersupply to the laptop (SMPS wallwart).

Does it matter (as long as maximum voltage at the BNC input is +/-20V)if I use a pro-grade X10/X20/X100 probe or if I use a voltage divider directly at the poweramp output and measure with ordinary test leads?

I was thinking on using a three resistor divider... something like 100k-10k-100k and measure over the middle resistor.


Also, could the above described method be used for checking 230V mains waveform?

Thanks in advance!


/Peter

picojohn
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Post by picojohn »

Hello Audioguy,

In addition to safety considerations, it may save you time and effort by using a high voltage probe such as the ADF25A (http://accessories.picotech.com/oscillo ... robes.html). It is an active differential oscilloscope probe which enables the measurement of signals not referenced to earth, therefore, mains voltages may also be tested.

Regards
John

Audioguy
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Post by Audioguy »

When using such a differential probe... is it a must to disconnect the PC from mains supply then?

Otherwise there will be two connections to ground and I assume that could cause problems?


/Peter

picojohn
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Post by picojohn »

Hello Audioguy,

You do not need to disconnect the PC from the mains power unit unless you experience power unit switching noise coupling through.

Regards
John

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