Current transformer will saturate here?

Discussion in 'General Electronics Discussion' started by eem2am, Nov 21, 2012.

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1. eem2am

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Aug 3, 2009
Hello

I have a 50KHz sinusoidal current which I must detect. The current is full wave rectified, so its actually pulsating DC half-sines.
The current is sinusoidal, but may be an average of 1A, or 2A, or 3A, or 4A…………..to 10A.

I must detect whether it’s a 1A, or a 2A , or a 3A……to 10A, that’s flowing………so I don’t need great accuracy, just to depict which one of these current levels it is that’s flowing.

Here is a picture of the 10A average rectified current that I must detect…..
http://i46.tinypic.com/2mxpjdg.jpg

….Do you think this is best done with a current sense transformer?

…..The DC level for the 10A one, is, exactly that ..10 Amps, and that seems an awful lot to put through a current transformer…transformers don’t like DC, surely.

I was wondering of the B82801B0205A100 (1:100) current sense transformer is up to this job?…..

B82801B series C.T. datasheet:-
http://www.epcos.com/inf/85/ds/b82801b.pdf

….the frequency range for almost all off-the-shelf current sense transformers is either 20KHz-50KHz or 50KHz-1MHz.
…..this makes it awkward for me because I am right on the boundary…i.e. 50KHz.

Also, the equation on page 5 of the B82801B series datasheet has a “duty cycle” parameter in it……..though my waveform, (shown above) is just a continuous train of half-sines…….so I don’t know what to put in for the “duty cycle” parameter?

So anyway, do you think the B82801B0205A100 C.T. will be OK for this job, and not saturate?

2. (*steve*)¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥdModerator

25,448
2,809
Jan 21, 2010
This looks like the same questions about the same circuit as

here https://www.electronicspoint.com/why-0-1-resistors-needed-opamp-cct-t254312.html
here https://www.electronicspoint.com/opamp-current-sense-peak-detect-ok-t254310.html
here https://www.electronicspoint.com/output-low-voltage-op-amp-t254296.html
and finally here https://www.electronicspoint.com/differential-op-amp-measure-current-t254119.html

There is a reason I keep closing your threads.

Use the one that is open or I'll have to give you a holiday to preserve my sanity.