LT Spice

[Demon]

Do any of you use LT Spice to run simulations at a basic level?



I can't afford the fancy pro stuff so I'm looking for a substitute. I'm noticing that a lot of the tutorials are aimed at those that know what they're doing already.

This series looks interesting but even that one may be a bit advanced. There's a lot of text in there I don't know what it means.

http://www.simonbramble.co.uk/lt_spi...tutorial_1.htm

I was hoping one of you had figured this out and had a "this is how you use LT Spice for dummies" tutorial.

Robert

[AvionicsMaster1]

I tried it a few years ago and gave up primarily because I couldn't get it run. I eventually found you have to tell it how long to run and what freq, etc., etc.,

I never did find a book or website that dipped low enough to my level. We found a pot of money at work and I was able to purchase Proteus. It is pricey and takes some work to use effectively but I really like it. I never did find any mid level sim program.

[Demon]

I'm still looking for a switch. I saw a voltage-controlled and current-controlled switch, whatever that is, but no momentary on pushbutton, toggle, rocker or anything of the sort.

I did see the panel where I enter a duration, also saw that we get voltage/current probes pop up at appropriate places. But that's it, I'm really hoping this can be used at our level 'cause Proteus is just out of my reach.

I'm gonnna go through that first chapter again, put in whatever values they say to use and see how it goes. Then slowly adapt for my use. One problem I see right away is the lack of PICs, if I have to manually enter those in, that's going to be overwhelming. I might as well build the breadboard, it'll take less time for me than to tell Spice the properties of all the pins.

I'm afraid this will be for discrete components only and I never do those. Too bad Microchip doesn't distribute a Spice library.

Robert

[Demon]

I didn't know about MPSIM:http:
http://www.microchip.com/development...gs_mplab3.aspx

I think you have to work in 2 parts; ie: a discrete circuit that generates a waveform in LT Spice, when you have that working, then define the waveform on the proper pin in MPSIM.

I've looked at a few forums that asked the same thing for PIC mcus, but there doesn't seem to be anything floating out there. One guy did suggest to simulate what a pin does with discretes:
http://www.microchip.com/forums/m107511-print.aspx

Robert


EDIT: Lots of free spice libraries here:
http://www.emwonder.com/spicemodels/

[pedja089]

As far as I know LT Spice isn't real time simulator, so there is no need for switch. You draw schematic, then simulate, and you get results.
It is used for advanced simulation... And there are several simulation modes, transient steady state etc...
Try proteus 7, if you want to simulate PIC in real time.

[Demon]

All the free downloads of Proteus 7 (now at v8) that I could find had a string attached, like:
http://wiseconvert.com/tos/

Basically saying "We're giving you this older version BUT you have to install our POS software that has 3rd party software that may do anything they please to your PC, you, and your decendants for 10 generations."

I think I'll pass.

Robert

[AvionicsMaster1]

Agreed on the no switch in LtSpice. You run the sim with ckt on then again with ckt off. Comparing results afterward.

I'm not sure if it's still around but I used Electronics Workbench for quite a while. I've only found one place that actually let me install Proteus of any version. I'll not make the company mad by posting the link.