http://polly.phys.msu.su/~zeld/oscill.html Seems quite good. I conncted my mp3 player to the mic jack to test it. Im wondering what sort of stuff can I connect tothe sound card input without damaging it, I.E max voltage... and stuff If I wanted to look at a signal, 50v dc for example, how would I get it down to a voltage that wont degrade the signal yet make it safe for the sound card? If I do use it, itll most likely be with low voltage, less than 12, is that safe?
Line input on the soundcard is probably around 1V RMS max, maybe 2V which some domestic CD players go up to, so signal attenuation is needed on anything over that. Two resistors as a potential divider is the simplest way, or use a 47k log volume pot and always start with it turned down. Mic input will be a lot less.
I remember using this maybe 12 months ago, as a bit of a lark. You can probably get away with going a little above the specs, since sound cards are built fairly tough. And a potential divider should be alright. Just, depending on how much you are dividing the input by, I might be a little sceptical as to accuracy in relationship to resolution on the part of the soundcard's ADC. English: will work, but may not be all that accurate. If you want accuracy, hook a $5 ADC to a port.
