SCT-013-000 CT question

Might be a really obvious question, but I am looking at the SCT-013-000 CT and it has a 'stereo' jack. Yet schematics that use the CT have only positive and negative. So what is the third contact used for? I would guess that the tip is positive, the sleeve is negative? So what is the ring for?

My interest is in a homemade energy monitor so I need to understand the inner workings of the CT.


Robert Wall's picture

Re: SCT-013-000 CT question

The CT is a transformer, transformers work on alternating currents only, so there is no "positive" nor "negative". But phase is important if you need to know the direction of power flow.
There is no connection to the ring. More details are in the report in Building Blocks. You can get CT theory from any standard electrical engineering text book.

hswiftj's picture

Re: SCT-013-000 CT question

OK I guess it is more 'in and out' rather than 'positive and negative'.

I didn't realise the sleeve could be taken off the 3.5mm jack; I found out myself there is nothing connected to the sleeve!

Thanks for your help.

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