Hi,
I am studying LC circuit now. I have a question, hope someone can help.
1. A series LC circuit with a signal source. Measure the voltage on the capacitor.
2. if the input is a step function, the output is a sinusoid whose frequency is LC's resonance frequency.
http://bbs.elecfans.com/data/attachment/forum/201303/07/081922t3aazv5ez9eg98a9.png
3. if change the the input to a sinusoid whose frequency is LC's resonance frequency. the output goes to infinate. I understand in this case the LC's impedance is 0 at this frequency.
http://bbs.elecfans.com/data/attachment/forum/201303/07/082136xd4dp48zbue3zp3p.png
4. But i checked the fourier transform of the the step function. It's spectrum covers the whole frequency (from 0- infinate). To my understanding it contains many many sinusiods , including the resonance frequency. And step 3(sinusoid input)'s response should be a part of the the step response.
how come the step response is amplitude limited, but sinusoid input response is infinate.
Where is my mistake, could someone tell me? Thanks a lot.
http://bbs.elecfans.com/data/attachment/forum/201303/07/082329wzdyl2lda22zdfq3.png
I am studying LC circuit now. I have a question, hope someone can help.
1. A series LC circuit with a signal source. Measure the voltage on the capacitor.
2. if the input is a step function, the output is a sinusoid whose frequency is LC's resonance frequency.
http://bbs.elecfans.com/data/attachment/forum/201303/07/081922t3aazv5ez9eg98a9.png
3. if change the the input to a sinusoid whose frequency is LC's resonance frequency. the output goes to infinate. I understand in this case the LC's impedance is 0 at this frequency.
http://bbs.elecfans.com/data/attachment/forum/201303/07/082136xd4dp48zbue3zp3p.png
4. But i checked the fourier transform of the the step function. It's spectrum covers the whole frequency (from 0- infinate). To my understanding it contains many many sinusiods , including the resonance frequency. And step 3(sinusoid input)'s response should be a part of the the step response.
how come the step response is amplitude limited, but sinusoid input response is infinate.
Where is my mistake, could someone tell me? Thanks a lot.
http://bbs.elecfans.com/data/attachment/forum/201303/07/082329wzdyl2lda22zdfq3.png