interesting documents:

Increased voltage phenomenon in resonance circuit of unconventional magnetic configuration.

clean energy laboratory natural group corporation Japan

http://underservice.org/index.php?action=dlattach;topic=3.0;attach=227

Wings, thankyou very much

I was looking for a sophisticated inductance calculator (there are many unsophisticated ones out there !) when i came across this article, read the section 'Stray Capacitance And Self-Resonance', i was surprised to see it mentioned as standard knowledge !

*** EDIT ADD ***

Ooops ! forgot link :

http://lcbsystems.com/InduCalc.html



Cheers,

DC.

Guys who are using soundcard oscilloscopes be careful when measuring resonant circuits. Resonating coils might exhibit higher voltages than a soundcards input can handle and might emit EMF that can also damage all kinds of electronic devices in the vicinity.

@deepcut: Yes it is known, but usually resonance is something to be avoided in electronic circuits. Also for the reasons above.

Quote from: chalamadad on October 13, 2011, 11:39:44 AM
Guys who are using soundcard oscilloscopes be careful when measuring resonant circuits. Resonating coils might exhibit higher voltages than a soundcards input can handle and might emit EMF that can also damage all kinds of electronic devices in the vicinity.

@deepcut: Yes it is known, but usually resonance is something to be avoided in electronic circuits. Also for the reasons above.

for dangerous test use USB sound cards 1.5 $

http://www.ebay.com/itm/USB-2-0-3D-AUDIO-SOUND-CARD-ADAPTER-VIRTUAL-5-1-/250383709893?pt=LH_DefaultDomain_0&hash=item3a4c0836c5#ht_845wt_907

galvanic 1000v usb isolator
http://electronics-shop.dk/?id=1038&google=1
http://www.circuitsathome.com/measurements/usb-isolator