26 Apr
2010
26 Apr
'10
8:18 p.m.
On 4/26/2010 12:25 PM, Tony Duell wrote
> I can think of one very good reason : If
you're the sort of mortal whose
> designed don't always work first time, or if you prefer to desgin a bit,
> get that working, add on the next bit, and so on, then it's a lot easier
> to do tha, make changes, modify things on prototyping board than on a PCB.
>
I'm not sure that's a valid reason. It's pretty easy to make
mods on a
PCB as well, unless the initial design is really FUBAR.
> And I wondeer... For a one-off project how does
the time taken to lay out
> the PCB check it, etc compare to thr time taken to wire it up by hand on
> a prototyping board.
>
If (and a big IF) someone is very good at reading pin numbers backwards,
has good prototyping skills, and doesn;t get in a hurry, I'd say the
prototype direction wins. But, I can see that swinging in favor of PCBs
very easily:
* It's easy to get messed up while looking at the back of a board as
to pin numbers. Sure, they make guides for that, but then that's
just another product you need to have in your kit.
* You still have to design it in something (napkin, graph paper,
etc.) For ultra simple (<10 major components) designs, I can see
the napkin as OK, but beyond that, hand drawn schematics (that
don't take as much time as a PCB app) get hard to read and prone
to error.
* Moving from idea to prototype can be addictive to the point that
corners are cut, creation is done in haste, and then mistakes are made
Probably the most important reason
* wirewrapping and such don't work nearly as well with SMT. You
either need to buy SMT->through hole adapter boards (another item
to stock in the kit), or use kynar, glue, and a patient hand to
solder a "dead bug style" SMT IC to your prototype
The last item is what drove me to PCB for all my projects. Many newer
parts only come in SMT variants.
Jim