neazoi
Advanced Member level 6
Hi, I have a TN9/6/3 3R1 toroid and I would like to find out of I can switch it's magnetization using my RF signal generator operating at 7MHz AC.
I follow the procedure in this page https://meettechniek.info/passive/magnetic-hysteresis.html and especially the part entitled "Measuring arrangement with a digital oscilloscope". The scope is the HP 54520A.
I switch my generator on (50R around 7dBm) and I use the "Versus" function (pp173 in the manual) of the scope (X-Y mode).
With this setup, I see a curve very similar to this https://meettechniek.info/extern/images/square-ferrite-3r1.png (the black one). However in my experiment, the very top and the very bottom lines of the curve are completely parallel to the scope grid lines, in contrast to this picture.
Also, when I reduce the generator power, gradually, I start seeing a waveform more like an elipse (which I assume means that the core cannot be switched) and not a line like the blue curve of this picture https://meettechniek.info/extern/images/square-ferrite-3r1.png
I am confused in the description of the procedure in the page.
First it says:
"When a digital oscilloscope is used the coil voltage could be digitally integrated. Of course the scope must therefore have the math options including integrating signals..."
And then it says:
"In the X-Y mode the field strength H is plotted on the X-as, and the flux density B on the Y-as."
So do I do the right thing to switch the scope to the X-Y mode, or do I need to switch it in the integrate function? Btw, when I switch it to the integrate function a very low power sinewave is shown. It is only in the X-Y mode (versus) that I see a curve similar to the hysterisis loop.
Apart from this, I am not sure if the core is switched, or if the very top and bottom lines are just some kind of clipping from the scope. But wouldn't this "clipping" occur then at all sides of the loop (top left and bottom right as well)?
Please give me some advice on these issues.
I follow the procedure in this page https://meettechniek.info/passive/magnetic-hysteresis.html and especially the part entitled "Measuring arrangement with a digital oscilloscope". The scope is the HP 54520A.
I switch my generator on (50R around 7dBm) and I use the "Versus" function (pp173 in the manual) of the scope (X-Y mode).
With this setup, I see a curve very similar to this https://meettechniek.info/extern/images/square-ferrite-3r1.png (the black one). However in my experiment, the very top and the very bottom lines of the curve are completely parallel to the scope grid lines, in contrast to this picture.
Also, when I reduce the generator power, gradually, I start seeing a waveform more like an elipse (which I assume means that the core cannot be switched) and not a line like the blue curve of this picture https://meettechniek.info/extern/images/square-ferrite-3r1.png
I am confused in the description of the procedure in the page.
First it says:
"When a digital oscilloscope is used the coil voltage could be digitally integrated. Of course the scope must therefore have the math options including integrating signals..."
And then it says:
"In the X-Y mode the field strength H is plotted on the X-as, and the flux density B on the Y-as."
So do I do the right thing to switch the scope to the X-Y mode, or do I need to switch it in the integrate function? Btw, when I switch it to the integrate function a very low power sinewave is shown. It is only in the X-Y mode (versus) that I see a curve similar to the hysterisis loop.
Apart from this, I am not sure if the core is switched, or if the very top and bottom lines are just some kind of clipping from the scope. But wouldn't this "clipping" occur then at all sides of the loop (top left and bottom right as well)?
Please give me some advice on these issues.
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