Putting a negative bias on the scope probes

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Tomblueprintauto
OneWave
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Putting a negative bias on the scope probes

Post by Tomblueprintauto »

I was watching some video's of Bernie Thompsons and he's using an Escope from Automotive Test Solutions that puts a negative 2V bias on his probes somehow. This means that when you back probe a connector the voltage is lifted to 0V (or higher) and you can be confident that you have a good connection.

This seems like a great idea as sometimes when checking ground voltages you never know if the ground is good or if you just haven't back probed correctly.

Can this be done on the Picoscope?

Alan
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Re: Putting a negative bias on the scope probes

Post by Alan »

Have a look at the ConnectDetect feature towards the end of this page https://www.picoauto.com/library/traini ... onus-class

Steve Smith
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Re: Putting a negative bias on the scope probes

Post by Steve Smith »

Hello and thank you for the posts

To follow up on Alan’s link above, if you are using PicoScope 7 Automotive software, Connect Detect can be activated as described here viewtopic.php?p=100443#p100443

Regrading confirmation of good ground, I would tread carefully relying solely upon Connect Detect as means to prove a sufficient ground given the current used is miniscule yet sufficient to detect a “link” exists between the test lead signal and ground reference wires

The intelligence of Connect Detect can also provide confirmation of test lead connection to a number of high impedance sensors which demonstrates how you could be led to believe your ground is true ground.

For confirmation of ground, a load test remains the better option

I hope this helps, take care…..Steve

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