Jump to content
Electronics-Lab.com Community

PC capacitor meter


Guest AngeloFranca
 Share

Recommended Posts

Guest AngeloFranca

Hi people!
I' m sure you know about PC oscilloscopes: they use soundcard as an input and show the signal waveform on the screen. I' d like to use this oscilloscope and a sinusoidal generator,(alsopreset in some of this freewave software), to make a setup to measure capacitors. I hope to plot capacitor's impedence in the range 20Hz-20kHz. My major troubles are:
-how to compare fase shitf beetween input and output;
-how soundcard input impedence,(which I don't really know), must be considered.

Any idea is well accepted!
Thank you so much

Link to comment
Share on other sites

  • 9 months later...

1.  Two input channels of the sound card must be used, one to capture the signal from the DUT (in your case, a capacitor), the other to capture the signal directly from the sound card output channel. By comparing these two signals, the phase shift introduced by the DUT can be obtained. This method assumes that no phase shift difference is introducted by the two sound card input channels, otherwise some sort of compensation is required.


2. Sound Card input impedance is a unknown during the tests. It can be measured by two tests, i.e. with and without a known resister in series. 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
 Share

×
  • Create New...