Funny - How to make a PCB

"Carl Smith" schreef in bericht news: snipped-for-privacy@news.west.earthlink.net...

Explains a large part of the price tags on electronic equipment :)

petrus bitbyter

I've been through #25 but with an octal latch. Because of that, I've added a step: print the board on paper and place all your parts on it to make sure they fit.

And the cost of #5 got me involved in the gEDA/PCB project :-)

Worth sending that link to those clowns who post " I am going to design a ( insert fabulous new device ) . How do I start ? ".

Graham

I remember it well. The original was (cross)posted here.

Damn! All I get is a 404 at the URL given.

Laugh or cry, you're not alone. I got caught out with the width of a boxed header and wound up having to file off one end to make it fit on the proto. As a result, except on trivially uncrowded boards I print off an overlay, paste it to cardboard, poke holes for leads and place components.

And on the last proto I did ( a week ago) the plastic pack on one particular IC was just a tad toooo long. Mr Dremel fixed that.

Somewhere I still have a small board where I did exactly that. It has a printout of the layout glued to some stiffer card stock, with all the through hole parts punched through the card.

Is that still a linux only thing?

I think my favorite is:

It reminds me of once when I got hit in the forehead with a ballistic piece of a 74HC logic chip.

My newsreader program decided to be helpful and word wrap the URL, breaking it in the middle. Put the two halves together with cut and paste in your web browser and it should work.

Try this one:

-- Regards, Bob Monsen

"Man with all his noble qualities, with sympathy which feels for the most debased, with benevolence which extends not only to other men but to the humblest living creature, with his god-like intellect which has penetrated into the movements and constitution of the solar system- with all these exalted powers- Man still bears in his bodily frame the indelible stamp of his lowly origin." -- Charles Darwin

Nope.

Yep, did that about three seconds after my previous post. Pays to look closely at posted URL's before clicking { :-0>

My recent experience:

IIRC the tools run under Windows with various levels of effort.

At the moment, I'm in the middle of re-engineering the PCB layout software to support multiple GUIs in the source set, so that (hopefully) we can later add a native Win32 GUI to it.

My working sources are here if anyone is interested:

I post an occasional status to the gEDA developer's list.

Alternatively you could try Kicad - open source and already running on both Linux and Windows. Look here:

Ian

Ah yes, all true. before CAD programs were available, you could add a few more:

(1) Find out you laid out all the IC's backwards-- end up bending the IC leads so the part numbers are all face down. Try to explain this to the production folks as a "trade secret" protection step.

(2) One of your many hairs that fell out stuck to the negative-- hand-patch a dozen hairline broken traces on the PC boards.

(3) The photoresist doesnt develop properly on dry days-- take the PC boards for an hour at the YMCA steam bath.

Quote them in angle brackets:

They forgot 11a) Verify that all traces go somewhere and connect to something.

I have designed many traces that go somewhere but connect to nothing. Or sometimes they go somewhere and then come back by a different route. Nothing wrong with that, when you need them.

One of the neat things the "new" pcb will be able to do is this:

• bring up the netlist dialog box.
• click on the first net. It gets highlighted on the board.
• press and hold the down arrow key.
• Each net gets highlighted in turn on the board as you auto-repeat down through the list.

Since your eyes and brain make a VERY powerful pattern matcher, even at full repeat speed you can still catch the occasional "odd" path.

And if you're working with high frequencies, it could be a tuning or impedance-matching stub. :-)

Cheers! Rich