Can Freeware CAD Tools Simulate and Design PCBs for a Beginner?

[PingPong]

Hi,

I'm not actually an electrical engineer (shh!) but I'm trying to do some circuit design to save our lab a little bit of money. We're looking to count triggers from a discriminator in a NIM crate.

I've put together a prototype pulse counter on a bread board using some 74190 divide by ten counter chips, 7447 BCD display drivers, and some seven segment displays. Right now, it counts up to 99 (two digits) and for the experiment we're looking to count up to 7 digits which is going to be really simple now that I know how to chain the counters together.

Now, I need three of these counters, so I think that a printed circuit board is going to be the easiest way for me to assemble them quickly and in a permanent fashion. I've decided to try to design this on my own (again to save money) and so I've tried using Diptrace. It's fairly intuitive and I've been able to design the circuit almost completely (I'm not sure what pin layout to use for the seven-segment displays I've got, part number LSD5061-11) but I want to make perfectly sure that the circuit will work as it is supposed to before we buy the PCBs. To do that, I'd like to design the circuit in some CAD software that I can use to test it, then use that design to automatically generate a PCB.

So, is what I'm trying to do even possible? I'm very new to the world of building circuits with chips, this is only my second time really dealing with them so it may just be a fantasy. If something like this does exist, I'd prefer it to be freeware that can run under Linux, any and all alternatives are possibilities.

Thanks in advance for your time!

 

[stragz]

if you want to buy workbench, I've tested a 200Wrms power amp with it, then designed it and the from my expierence, and the results I've calculated , workbench does a fine job (does cost a penny tho if you want it legally)
for pcb desiging software try out layo, again it will cost a penny
somewhat more physical work, but less using your head and learning to work with pcb software
go buy chalkpaper( litturally translated from dutch) it is semitransparent paper, you can first draw out a pcb layout on normal paper, correct, then you take a black pen and put the transparent paper on top of it, you redraw the lines
then you go to electronics shop and ask them to make a pcb out of it ( be sure to mark the right side, or you'r pcb will be mirrored
personally, i only design pcb's myself, i don't make them (with making i mean using acid toget rid of the excess copper)for the following reasons:
1 the products are toxic, and environmental unfriendly
2 the products are expensive and expire rapidly
3 the chances of failing without the right equipment are high

as you know the clean pcb boards have a lightsensitive layer on top of the copper, first you need to use uv light to get rid of that layer( if you are in a room with to mucht sunlight your print is already wasted)
then you have to put it in a bath of acid, to get rid of the excess copper, what are you going to do with the leftover acid? its not something you can pour down the drain ...
here in belgium there are heavy fines on that
and then you need to drill the holes,..
if you don't have this equipment ready for use, you have to buy all of that, then you could just as well buy 4 premade counters :pps(edit):if you are looking for 2 programs that can interact to do the schematic for you
try out tina pro + layo pro
altho workbench does fine to

 

[pantaz]

Here are some freeware options:
http://www.cadsoftusa.com/"

http://www.expresspcb.com/ExpressPCBHtm/Free_cad_software.htm"