0
\$\begingroup\$

I have a digital little oscilloscope that can handle up to 35 [V] in the input. As far as I know, we use x10 probes for high frequency circuits and that stuff but my doubt: if I have a x10 probe, does it mean that I can input to my oscilloscope up to 350 [V] p-p (because it would be attenuated to 35 [V] p-p)?

\$\endgroup\$
  • 1
    \$\begingroup\$ The probe might not be able to handle it. \$\endgroup\$ – Peter Smith Oct 5 '18 at 14:23
  • \$\begingroup\$ Try it at a low voltage and make comparisons. The deal is that if your scope input is 1 Mohm then it's likely to be fine but test first. \$\endgroup\$ – Andy aka Oct 5 '18 at 14:28
3
\$\begingroup\$

The 10x attenuation assumes that the oscilloscope has an input impedance of 1 MΩ. The probe itself has a 9 MΩ resistor in series (along with a capacitor for transient compensation). The actual voltage seen by the input of the oscilloscope is 1/10th of the voltage between ground and the probe tip.

While a 35V input is pretty low, I have seen the voltage rating of a (passive 10x) oscilloscope probe be lower than the attenuation factor times the voltage rating of the oscilloscope. I had a 10x probe rated for 400V, but the oscilloscope input was rated for 100V.

\$\endgroup\$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.