PCB Layout Software 1

[mlarson]

I am working for a small company that is finally at the step of needing to design a circuit board for one of our projects. Since we will only be doing a couple boards a year I don't need an advanced package. Also we are on a budget due to the low usage of the software. Does anyone have any recommendations for good packages? I have been looking at a package called Proteus from Labcenter Electronics but can't find many reviews on it...has anyone used this package? I've also looking at Cadsoft Eagle and it seems to have mixed reviews.

Thanks, Matt

 

[cbarn24050]

Hi, I think you've pretty much made my point for me. I dont know what your definition of "tricky" is, maybe you could elaborate. You make it sound like you throw a circuit together, simulate it to see if it does what you want, make some changes and repeat untill you get the desired result. It may be your way but its not mine. If it works for you thats fine.

 

[2dye4]

For instance
Today i making a layout of circuit that must have a
timing pulse generation with an accuracy/repeatability
of less than 30nS. Meaning i need a sequence of 2 pulses
with durations less than a clock cycle of a PIC and need
it to be repeatable to 30ns.
I have ordered the empty pcb without building a prototype
because of the difficulty of working with these dammm
&^^$&$# tiny surface mount parts.
I would not have very comfortable ordering this PCB without
testing my concept with a simulation.
I guess I could have done the calculations by other means
to verify the design but I don't see the point, thats what
spice is for, to do the calculations.
And of course I know the work is not done as I have not
modeled the trace capacitances of my pcb so I will have to
modify the final component values with a O-scope and do
some trial and error finish work. But I have a set of
values to start with that will put me very close in the
ball park thanks to my spice simulation.

So, give me an example of how spice has cost me time.

 

[cbarn24050]

As I said before, if there is a reason why you cant breadboard your design then spice is better than nothing. How much time did it take you? How well have you modeled it? I guess you already had the component models otherwise you would have had to spend alot more time, and of course you still dont know if it will work. Bear in mind as well the originator of this thread is not an expert like you, how long would you guess it would take him?

 

[2dye4]

It took me about 30 min.
I guess for me it comes down to this line of thinking.

If you don't use spice I ask if before you begin a circuit
design do you need to make any calculations to create or
verify the design. If not then I guess it is a simple
circuit. If you do calculate then I might suggest using
a spreadsheet to ease the burden of getting the numbers.
Or spice.

If you do not have faith in ability of spice to reasonably
model your parts, do you have better models running in your
head. If so why don't you publish a paper and become
famous. If you don't have better models in your grey
matter then why not use spice??

Of course spice is not for everybody. I just think it is
something that eventually proves beneficial to all
electrical engineers that practice their calling.
And I see no reason to discourage people from trying it
for themselves. They can each decide if it is usefull
to them or not.


I still can't get to understanding how a person can
calculate the response of a circuit faster,easier with
any other tool than spice.

We should get back to the original question posted by
mlarson about EDA and maybe start our own thread about
this if it is of interest to anyone.

later

 

[cbarn24050]

Hi again, the reason you did it quickly (aside from being an expert) is that you didnt actually simulate your circuit. What you did was a quick aproximation and then built a prototype which your now going to test and hope it works, so in prctice you do actally agree with me.

 

[analoguealan]

Have a look at "Easy PC ".

Cheap U.K based software that has been around for several years.

Regards

analogue alan