I have a decent PC o-scope; nothing special (Visual Analyser). I am wondering if I can use this software to poke around in amplifiers....some may have some pretty high voltages present!!

So the question is, is there a resonable way to be sure an input (via soundcard line in) will stay below a certain voltage (lets say 5V to be sure!)? I guess what I'm looking for is to scale the higher AC voltages (assume 200V) down to 5V, with a protective device in place to assure not blowing up the sound card (zener....).
Just an idea, and maybe a dumb one at that....thanks for any ideas!

 

Take a look at my project,

http://forum.allaboutcircuits.com/showthread.php?t=12149

which is my approach to the problem. Started construction, but never finished. On my to do list.

 

I would build a op amp buffer, perhaps gain of 1 with a high imput impedance. Protective clipping didodes can be use to limit input voltage after some input impedance in the op amp input stage. This should stop high voltages from getting in.

A voltage divider prior to the op amp will reduce the voltage.

 

Thanks guys, right along the line of what I was thinking. I would probably have to manually adjust a divider for 'ranges', and then run the signal thru a buffer.