"Winston" wrote in message
...
Ed Huntress wrote:
"Winston" wrote in message
...
Ed Huntress wrote:
"Michael A. Terrell" wrote in message
...
(...)

Have you ever tried 'SwitcherCad'? It is a Spice program you can
download for free from Linear Technology.

http://www.linear.com/designtools/software/ltspice.jsp
Second the motion.

OK, with both of you being enthusiastic, I downloaded it to try it out.
I'll get to it this weekend.

Thanks.

I'm interested in your reaction.

Notice how your mouse cursor changes from a voltage probe to a current
probe during simulation, depending on where you place it on the part.
Click to take a reading and the results show up on an oscilloscope -
type display.

LTSpice lets you create definitions for simulation measurements
using the Expression Editor.
You can, for instance dynamically calculate power in R1, for example by
editing it's current reading from: 'I(R1)' to: 'I(R1)*(V(n002)-V(n001))'
where the voltages are taken from each side of R1 to ground.
Notice how LTSpice automagically changes the display from 'amps' to
'watts'!


You can copy the equation and paste it into your schematic as a comment,
so it is handy for future simulations when you paste it back into the
Expression Editor.

Super Nifty.

--Winston

Sorry I've been offline for a while. I did get to try the program and it is
impressive -- 'way more capable than the early versions of Spice I fooled
with years ago.

If I still played with radio, I'd be hooked. Thanks for getting me to try
it.

--
Ed Huntress