basic inductance question

[leto]

I'm trying to practice the inductance principles, so I made a sine wave generator and connect it to coil. I must to analyze the inductance ouput of a secondary coil next to. My question is, Why the sine wave look distorted when I apply the sine wave signal over a primary coil ? What would I do ?. When I connect a cap to GND it looks better. My sine wave is 3vpp at 2,5khz.

Thank you
leto

 

[ceaser]

i think there is DC component in the sine wave you entered in the transformer

when you add the capacitor, it blocks DC component

this as i know

 

[zajbanlik]

Hi

I agree with you because than transformer enter saturation mode and its characteristic became nonlinear.

Regards

 

[leto]

may be... but it only happens when I put a specific cap value about 4.7 uF. if I put a bigger or smaller one the signal appear distorted. And I'm looking the signal with AC mode in the oscilloscope I suppose this must filter DC component. or not ?

I attached a oscilloscope output photo.
Thanks again.
leto

 

[zajbanlik]

Hi

Did you try to reduce amplitude of input signal?
It could be also helpfull to put resistor (let's say 220 Ohm in serie with coil) to reduce amplitude current.
Also concerning capacitor. Be aware that you mustn't use tantal or electrolit capacitor.

Regards

 

[kevinj]

the capacitor reduces distortion, but your scope has a dc & ac coupling option. try to switch the coupling from dc to ac.