PCB design and cicuit simulation software

Hi all first post here
could someone recommend a good software package for PCB and circuit design and simulation on a budget preferably compatible with windows vista and 7 and with CNC capability (looking to build one in the future)

sort by: active | newest | oldest
1-10 of 32Next »
OK I tried LTSpice

I built this Schmitt Trigger Inverter Oscillator in LTSpice and the real world.

No matter the Capacitor the DM74LS14N IC will only oscillate with a feedback resistor Value of 300 Ω to 3 kΩ.

It works in the real world but not in LTSpice, in LTSpice I could not run a simulation. Kind of defeats the purpose of a simulator.

For a simulator I find it not very satisfying.

I tried and liked Dipspice.

It took me a day to get the hang of the program.

It looks good for designing PCBs but it doesn’t simulate circuit functions and I don’t like the wire jumps.


Oscillator Post.bmp003.JPG
I just simulated the 74LS14-Squarewave oscillator with no problems...
Rebuilt it in real and f was off by 2.1% which is propably due to the crappy cap i used (Electrolyte is quite horrible in terms of accurancy)...

Please post your libs, models, syms and of course your ASC here. Then i will check out whats wrong with it. :)

Also i dont quite understand your sentence
"No matter the Capacitor the DM74LS14N IC will only oscillate with a feedback resistor Value of 300 & to 3 k&."
Do you mean in reality or in the sim?
In reality thats not the case and you can take whatever combination you want to satisfy the normal formula of the frequency,

I'd be interested in seeing your ASC files. I have to admit to being so old-school, I generally work things out on paper, but LTspice is fun to play with. One of the first things I did when I graduated was a numerical simulation of a linear power supply. Took me weeks. The first thing I did with LTspice was the same thing. Took me 2 hours. 1:55 of which was learning the system.
Version 4
SHEET 1 1332 680
WIRE 16 48 -48 48
WIRE 144 48 96 48
WIRE -48 144 -48 48
WIRE 0 144 -48 144
WIRE 144 144 144 48
WIRE 144 144 112 144
WIRE 160 144 144 144
WIRE 416 144 272 144
WIRE -48 192 -48 144
WIRE -48 288 -48 256
FLAG -48 288 0
SYMBOL 74HC\\74hc14 48 96 R0
SYMBOL 74HC\\74hc14 208 96 R0
SYMBOL cap -64 192 R0
SYMATTR Value 10µ
SYMBOL res 0 64 R270
WINDOW 0 32 56 VTop 2
WINDOW 3 0 56 VBottom 2
SYMATTR Value 1Meg
TEXT -56 344 Left 2 !.tran 0 60 0 startup uic
TEXT -56 376 Left 2 !.include 74LS.lib

See http://www.bilderload.com/bild/282360/squareI0I4D.png for the thing in action
Thanks. That worked, once I'd found the library !
Was that a MM74LS14 or an SN74LS14 or a DM74LS14 or a HD74LS14 all though they do the same thing in embedded binary codding they react differently in the real world circuits.

I do it in the real world, if I say it cannot be done I am wrong, if I say I did that, I did that.
It was a SN74LS14 i used and sim'd.
Other LS than SN are nothing to be found anymore where i work... Even for this SN74 i had to look for a long time...
I used DM74LS14N and have MM74LS14 HD74LS14 SN74LS14N in stock. Mind you I have over 100,000 components in stalk in my home lab.
However no matter what I do I can’t get it to run in LTSpice.
100k?!? Wow... You lucky person :) I wish i had access to 1/10th of that at the company...

Maybe there is only a little problem... Please post your ASC, LIB and SYM of the schem/the parts or tell me from where you got the LS-parts since they arent (anymore) part of the normal librarys supplyed with LTspice. Then i can check it out and maybe find out why it doesnt work...
Maybe there are simply some hidden powerpins which need a powered VCC-Label placed in the schem...
I was an electronics technician and owned a repair shop in the city before I got my engineering degree and everything went disposable. So some I bought and some I salvaged

I would give credit on working obsolete electronics and salvage the gold, silver, aluminum, copper, and working components.

Many ICs in older computers just plugged in so I removed the ICs and cut off all the gold baked off the copper.

Most of the time the gold, silver, aluminum, and copper paid for the credit. I got a bunch of studio video recorders at an auction for pocket change once they had 1lb of gold in them and over a hundred plugin ICs each.

Other than my TTL books I go to these websites for Data sheets on components,

A list of my ICs would fill two pages of four columns I can send it in a PM if you like.

1-10 of 32Next »