EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: darkstar49 on November 03, 2020, 09:14:22 am
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Sorry to bother with a probably stupid question, but as a software guy, I don't feel too much at ease with PSU troubleshooting, and I'd like to clarify some basics...
I've got the PSU connected to an isolation transformer, and using a differential probe connected to a scope to make various measurements... my question is in fact whether I should be worried to use a second (or third..., or...) differential probe connected to the (obviously same) scope, for probing the (same) PSU ??
I'm not too sure to fully understand the grounding implications when using several (diff) probes connected to the scope...
Thanks in advance for any feedback !!
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A differential probe has two inputs, both of which have a high (MOhm) impedance to ground. So there should not be a problem connecting multiple differential probes to the same circuit. Just make sure to obey the voltage rating of all probes, and be mindful of the parasitic capacitance of the probes. I would not connect multiple differential probes to the gate of a MOSFET, for example.
If the differential probes have a ground lead (not common on high-voltage differential probes), then you do need to be careful where and if to connect that ground lead.
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If the differential probes have a ground lead (not common on high-voltage differential probes), then you do need to be careful where and if to connect that ground lead.
this will apply exactly like normal passive probe's ground lead.