Lumpy wrote:

krackula wrote:

...it's older but will be all
you probably need for  this !

EW will do it I think. I used to have it on
a Win95 machine. The newer version I don't
like as well as the older.

Point me there. Thanks in advance.

Lump

For pure theory, you don't need electronics workbench. If you need
spice and a schematic capture, you can use Linear Technology's
switchercad.
http://www.linear.com/company/software.jsp

Besides switchercad, LT has filtercad. I haven't run filtercad in
years, but my recollection is was highly integated to LTs filter
products. Switchercad is just spice, i.e. you don't have to design
switch-mode power supplies with it.

Spice3 is a free. I run it on my linux machine using ngspice, but there
are probably 3 free versions that run under windows. If you have a 2nd
PC, setting up linux is the way to go. There is considerable free
electronic design software that only runs under linux. Linux itself is
free, though having broadband is required to download the OS. Suse 10
is 5 CDROMs.