Freeware Pspice says it will only handle 10 transistors. 5

[joecad]

I need to find the heat problem before I breadboard again. However, freeware ver. says it will only simulate up to 10 transistors and I have 14. I'm looking for a way around this for my PCDrill project.

Looking for ideas?

PS Thanks to those posts on my previous question re. PN2222.

joecad

 

[melone]

Can you put in a subcircuit? Break up part of your circuit and save it (make sure you put in input and output ports). Then place a dummy block in a new sheet and assign it to be equivalent to your saved circuit (inputs and outputs should be automatically assigned to the box). Then try adding the remaining transistors.

Just a thought.

 

[cybernut]

Hi

There is a very good spice demo program which should allow your circuit to be configured. Even though it is a demo it is has a generous number of nodes. It's called SiMetrix and is available from

http://www.newburytech.co.uk/Pages/intro.html

. I've used it for several years now. Give it a try.

C

 

[BrianG]

Yes, I agree with cybernut, I can thoroughly recommend SiMetrix (usual disclaimer). It has a brilliant intuative user interface, so you get going really quickly. Do yourself a favour and download a free copy. it has no expiry time limit and it's about 4.5MB

We use SiMetrix professionally, and wonder how we ever managed without it. We have the downloaded demo versions (several copies, which we use for initial sub-circuit design) and a full licensed copy for big network stuff.

The only difference is that the demo version limits the number of nodes to about 40, but it still has all the full Monte Carlo toleranceing statistical and temperature goodies. It also still allows you to add loads of Spice models for transistors and ICs that you can download for free from manufacturer's websites.

 

[Chancy99]

joecad -

PCDrill project - sounds cool. Can you provide more details ? Been looking for a good cheap home pcb milling machine for a while.

Dean.

 

[joecad]

I'm not familiar enough with breaking up circuits but I'll have to look into that eventually. Thanks.

I'm going to take up the advice on downloading SIMetrix.

Chancy99, I will refer you to my source Feb. 1997 issue of Electronics Now. The article is "Build the PCB Drill" by James J. Barbarello. This project is covered in more than one issue, three or four I believe.

I also experimented with a low end Mech. CAD modeling program and attempted to model the project. As well as redesign the PCB for smaller size for PTH and and when done will try an SMT design equivalent.

Website

http://e-m.design.i8.com

Thanks Again Everyone

joecad