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Old 11th Jul 2018, 8:46 am   #5
Radio Wrangler
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Location: Fife, Scotland, UK.
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Default Re: Gate drive/ (r) 'scope measurements

Quote:
Originally Posted by astral highway View Post
Hi Peter,


My ‘scope has a plastic case and is double-insulated so I could take your advice and lift the earth connection for this purpose.
You may find it has EMC capacitors bridging the scope's (now disconnected from mains ground) common and the line and neutral of mains. At the high frequencies you're trying to float the thing at you may have enough current in them to create some drama.

Just because there is no longer a copper connection doesn't mean that something is floating at higher frequencies.

It can be quite difficult designing an isolating transformer to isolate at high frequencies. Leakage inductance says you want to interleave windings, interwinding capacitance says you don't.

David
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