How do you design these days?
RogerN
When I was in school components fit on solderless breadboards and we made
circuits using breadboards, power supplies, meters and oscilloscopes. Many
of today's components don't appear to be breadboard friendly, so how is it
done today?
Is circuit design software and simulation good enough to go straight to a PC
board? Or do you use surface mount to breadboard adapters? Do you still
use a soldering Iron to solder or paste solder and an oven?
I'm wanting to tinker with some circuits but some chips I'm interested in
only comes in MSOP or other packages that look intimidating to attempt to
solder.
Thanks!
RogerN
Jon Kirwan
wrote:
You can stock up on a LOT of tiny SMT to through-hole boards and just
solder the SMT onto those and drop them into your solderless
breadboard or else wire-wrap sockets. Perhaps someone on the web
sells these in batches or else has a kind of nifty board with a bunch
of SMT outlines to through-holes on them and you can use that? Some
companies sell these expensive adapter boards, too. But they usually
aren't very cheap. Dead-bug point-to-point is another method. But
some of these things have really fine spacing -- usually you can find
a package with wide enough spacing to get by with.
Jon
Joerg
> When I was in school components fit on solderless breadboards and we made
> circuits using breadboards, power supplies, meters and oscilloscopes. Many
> of today's components don't appear to be breadboard friendly, so how is it
> done today?
>
I even used bare thumbtacks on plywood for solder posts back then.
> Is circuit design software and simulation good enough to go straight to a PC
> board? Or do you use surface mount to breadboard adapters? Do you still
> use a soldering Iron to solder or paste solder and an oven?
>
In the professional world (product design) we go straight from
simulation to schematic -> layout -> board fab -> assembly. No breadboards.
> I'm wanting to tinker with some circuits but some chips I'm interested in
> only comes in MSOP or other packages that look intimidating to attempt to
> solder.
>
Well, for hobbyists or one-off designs there is help but not very cheap:
http://www.proto-advantage.com/store/images/PRODUCTS/PA0027_0.JPG
This is the variety they have but I don't know this shop, just meant as
an example:
http://www.proto-advantage.com/store/index.php?cPath=2200
--
Regards, Joerg
http://www.analogconsultants.com/
"gmail" domain blocked because of excessive spam.
Use another domain or send PM.
a7yvm1...@netzero.com
> When I was in school components fit on solderless breadboards and we made
> circuits using breadboards, power supplies, meters and oscilloscopes. Many
> of today's components don't appear to be breadboard friendly, so how is it
> done today?
>
Depends... You can buy surfboards at Digikey, at least that'll get you
soic style breadboards you solder to.
> Is circuit design software and simulation good enough to go straight to a PC
> board? Or do you use surface mount to breadboard adapters? Do you still
Only if you're supremely confident or it's a simple circuit.
> use a soldering Iron to solder or paste solder and an oven?
A fine tip iron with fine solder should be good enough.
> I'm wanting to tinker with some circuits but some chips I'm interested in
> only comes in MSOP or other packages that look intimidating to attempt to
> solder.
>
Buy some other chip in the same package that's cheaper to practice.
Bill Sloman
For fast circuits, where cross-talk and transmission line effect can
be important, there isn't much point in building a prototype on a
breadboard - the printed circuit layout is a crucial part of the
design.
This doesn't mean that the printed-circuit base prototype is going to
work first time, even with the best circuit design software and
simulation. Something always seems to go wrong, though with careful
and expert engineers it is rare that you can't get the circuit working
with a little bit of cut and link.
For lower-frequency work, turn the MSOP packages up-side done and glue
them - dead-bug style - to your prototyping board, and solder wire-
wrap wire or enamelled transformer wire (both around 30 SWG - 0.3mm OD)
onto the leads.
The last time I did this, I ended up using a prototyping board with a
"collander ground plane" on one side, and cut up the rings of copper
around the lead-holes on the other to get enough small pads close
together to keep the wiring compact. It worked quite well.
--
Bill Sloman, Nijmegen
Tim Wescott
> RogerN wrote:
>> When I was in school components fit on solderless breadboards and we
>> made circuits using breadboards, power supplies, meters and
>> oscilloscopes. Many of today's components don't appear to be
>> breadboard friendly, so how is it done today?
>>
>>
> I even used bare thumbtacks on plywood for solder posts back then.
>
>
>> Is circuit design software and simulation good enough to go straight to
>> a PC board? Or do you use surface mount to breadboard adapters? Do
>> you still use a soldering Iron to solder or paste solder and an oven?
>>
>>
> In the professional world (product design) we go straight from
> simulation to schematic -> layout -> board fab -> assembly. No
> breadboards.
Although if it's a really complex board it may suffer a few mods before
it's really done.
D from BC
wrote:
>
My motto:
If it works on a breadboard, it's not worth producing.
On my current project, I have to feed the simulator pcb parasitics and
component parasistics to get accurate simulations.
I've had to bench test to get some parasitics. Once parasitics are
included, scope results and simulation results get close.
If all looks good on sim, I make a pcb, etch it and bench test it.
I trashed all my breadboards years ago and only work with smd parts.
I do hot plate soldering.
It's that or ....
I put the micro leprechauns to work with tiny soldering pens.
krw
wrote:
>RogerN wrote:
>> When I was in school components fit on solderless breadboards and we made
>> circuits using breadboards, power supplies, meters and oscilloscopes. Many
>> of today's components don't appear to be breadboard friendly, so how is it
>> done today?
>>
>
>I even used bare thumbtacks on plywood for solder posts back then.
>
>
>> Is circuit design software and simulation good enough to go straight to a PC
>> board? Or do you use surface mount to breadboard adapters? Do you still
>> use a soldering Iron to solder or paste solder and an oven?
>>
>
>In the professional world (product design) we go straight from
>simulation to schematic -> layout -> board fab -> assembly. No breadboards.
In our case, "assembly" is fully automated pick-n-place on the same
line as the manufactured board. For a new board manufacturing will
use it for the temperature profile too. We have a prototype machine
for raw boards but it's never worked. If they can get it to work I
may use it for a few test circuits.
John Larkin
<bill....@ieee.org> wrote:
>On Dec 31, 3:01�am, "RogerN" <re...@midwest.net> wrote:
>> When I was in school components fit on solderless breadboards and we made
>> circuits using breadboards, power supplies, meters and oscilloscopes. �Many
>> of today's components don't appear to be breadboard friendly, so how is it
>> done today?
>>
>> Is circuit design software and simulation good enough to go straight to a PC
>> board? �Or do you use surface mount to breadboard adapters? �Do you still
>> use a soldering Iron to solder or paste solder and an oven?
>>
>> I'm wanting to tinker with some circuits but some chips I'm interested in
>> only comes in MSOP or other packages that look intimidating to attempt to
>> solder.
>
>For fast circuits, where cross-talk and transmission line effect can
>be important, there isn't much point in building a prototype on a
>breadboard - the printed circuit layout is a crucial part of the
>design.
I test GHz stuff by hacking a piece of FR4...
ftp://jjlarkin.lmi.net/BB_fast.JPG
You can get the impedances pretty much correct.
For slower stuff, I like the Bellin adapters
ftp://jjlarkin.lmi.net/NE3509M04.JPG
I hate those solderless breadboards. I like to build things live-bug
on copperclad, comment them with a marker pen, and keep them.
John
John Larkin
<myreal...@comic.com> wrote:
>On Wed, 30 Dec 2009 20:01:39 -0600, "RogerN" <re...@midwest.net>
>wrote:
>
>>
>>When I was in school components fit on solderless breadboards and we made
>>circuits using breadboards, power supplies, meters and oscilloscopes. Many
>>of today's components don't appear to be breadboard friendly, so how is it
>>done today?
>>
>>Is circuit design software and simulation good enough to go straight to a PC
>>board? Or do you use surface mount to breadboard adapters? Do you still
>>use a soldering Iron to solder or paste solder and an oven?
>>
>>I'm wanting to tinker with some circuits but some chips I'm interested in
>>only comes in MSOP or other packages that look intimidating to attempt to
>>solder.
>>
>>Thanks!
>>
>>RogerN
>>
>
>My motto:
>If it works on a breadboard, it's not worth producing.
>
>On my current project, I have to feed the simulator pcb parasitics and
>component parasistics to get accurate simulations.
>I've had to bench test to get some parasitics. Once parasitics are
>included, scope results and simulation results get close.
>
>If all looks good on sim, I make a pcb, etch it and bench test it.
One problem is that device models often aren't available for fast
parts, or all you get are S-params when you need large-signal
time-domain stuff. So sometimes you can learn a lot by hacking some
FR4 and testing parts.
I never breadboard entire products, or even complex circuits... just
enough to characterize parts or simple subcircuits.
This is an EL07 driving a PHEMT...
ftp://jjlarkin.lmi.net/BB_fast.JPG
which made decent 5-volt, 1 GHz square waves.
John
markp
"RogerN" <re...@midwest.net> wrote in message
news:ROudnXLvg9-Tm6HW...@earthlink.com...
I tend to design a PCB with CAD software then have prototype PCBs made.
There are several companies out there who do 'pooling', i.e. they amalgamate
many designs onto one PCB, that way you end up only paying a small fraction
of the tooling cost of the PCB. Some companies can handle 6 layer boards
with this process. Example in the UK is PCB Snap from Spirit Circuits
(www.spiritcircuits.com).
This can be quite cost effectve for producing protptypes that are as close
to the final product as practicable.
Another way is to design with CAD but make your own PCBs. One way that works
reasonably well is to produce gerbers and print them in mirrored form on a
laser printer with high contrast (i.e. lines are as black as possible) onto
glossy paper, then use an clothes iron to transfer the image directly to a
sheet of copper laminate, and then etch. The reason this works is the ink is
somewhat resistant to the etching chemicals. There is a product that is
specifically designed for this (can't remember its name, it uses blue paper
to ease the transfer process), do some Googling for homemade PCBs.
As for soldering, with a fine tip soldering iron and a little practice it's
not that difficult to solder a MSOP or TQFP to a PCB. Get yourself a good
magnifying glass on a stand, lots of no-clean flux, some silver laden
solder, and the most important part small thin solder braid for tidying up
the inevitable shorts between pins and your away.
Mark.
MooseFET
I use ExpressPCB to make boards for parts of the design. Things like
power supplies are made as a PCB with connectors that are wired to the
other boards. I use 1206 parts and put in some extra parts and layout
such that cuts and jumps are easy(ish) to do.
>
> Thanks!
>
> RogerN
Raveninghorde
Think. Read data sheets. Think. CAD. Make on production line.
Pcb design rarely takes longer than a lash up on strip board or
whatever and always works better.
Very occasionally I have lashed up a small part of a design but I
almost always regret the waste of time.
I like to get things to production as soon as possible. As many issues
get highlighted in production that alter the design as get found
during debugging.
The new reflow oven gets commissioned on Monday which I hope will
reduce some of these production snags. Like LEDs die but inductors
don't solder.
John Larkin
wrote:
>
>"RogerN" <re...@midwest.net> wrote in message
>news:ROudnXLvg9-Tm6HW...@earthlink.com...
>>
>> When I was in school components fit on solderless breadboards and we made
>> circuits using breadboards, power supplies, meters and oscilloscopes.
>> Many of today's components don't appear to be breadboard friendly, so how
>> is it done today?
>>
>> Is circuit design software and simulation good enough to go straight to a
>> PC board? Or do you use surface mount to breadboard adapters? Do you
>> still use a soldering Iron to solder or paste solder and an oven?
>>
>> I'm wanting to tinker with some circuits but some chips I'm interested in
>> only comes in MSOP or other packages that look intimidating to attempt to
>> solder.
>>
>> Thanks!
>>
>> RogerN
>>
>>
>
>I tend to design a PCB with CAD software then have prototype PCBs made.
>There are several companies out there who do 'pooling', i.e. they amalgamate
>many designs onto one PCB, that way you end up only paying a small fraction
>of the tooling cost of the PCB. Some companies can handle 6 layer boards
>with this process. Example in the UK is PCB Snap from Spirit Circuits
>(www.spiritcircuits.com).
>
>This can be quite cost effectve for producing protptypes that are as close
>to the final product as practicable.
Why not go for the real thing, first time? If you get it right, you
can sell it.
John
Don Lancaster
It is NEVER right the first time.
--
Many thanks,
Don Lancaster voice phone: (928)428-4073
Synergetics 3860 West First Street Box 809 Thatcher, AZ 85552
rss: http://www.tinaja.com/whtnu.xml email: d...@tinaja.com
Please visit my GURU's LAIR web site at http://www.tinaja.com
Jan Panteltje
<d...@tinaja.com> wrote in <7q40n8...@mid.individual.net>:
>> Why not go for the real thing, first time? If you get it right, you
>> can sell it.
>>
>> John
>>
>
>It is NEVER right the first time.
I have done boards with more then 30 chips that worked right the first time.
Good thing too, as having them layed out and made was expensive.
John Larkin
wrote:
We sell about 80% of our rev A boards, with no prototypes. Assuming
the first unit won't work is self-fulfilling, and a good way to make
sure the third iteration won't work either.
And my cabin automation hardware worked absolutely unaltered the first
time!
John
markp
Well, I would if I were selling them. I'm a consultant designer, so
generally I deliver working protoypes on the undestanding they are just
prototypes and the customers make the first small batch. Given that the
actual design information will probably need to be tweeked slightly anyway
to match any mods I make it's not worth me spending more money than
necessary. For a hobbyist making one or two off it's really not worth it.
Mark.
markp
"John Larkin" <jjla...@highNOTlandTHIStechnologyPART.com> wrote in message
news:7glpj5l1a7i5nm45b...@4ax.com...
I have to say most of my designs usually work with only a slight
modification (sometimes none, sometimes component changes, sometimes the odd
wire or track cut).
Sometimes though it's easy to assume something works when actually it's
close to the edge, but you still need to thoroughly examine the product
anyway. We all know that sometimes there are real pressures to ship, in some
respects a board that doesn't work first time can be beneficial in focusing
attention to smaller details. Of course the design has to be tested
thoroughly anyway, what I'm saying is it can speed that process up if the
thing doesn't work first time and you've got real pressure to get it out the
door :)
Mark.
Joel Koltner
news:7q2g2r...@mid.individual.net...
> In the professional world (product design) we go straight from simulation to
> schematic -> layout -> board fab -> assembly. No breadboards.
Oh come on, even you occasionally dead bug-up (or otherwise prototype) a
tricky circuit that's part of a bigger product, right?
John Larkin does it plenty! :-)
markp
"Don Lancaster" <d...@tinaja.com> wrote in message
news:7q40n8...@mid.individual.net...
Analogous to the software world where every program has at least one bug and
can be re-written in a better way with fewer lines. So therefore every
software program can be reduced to one line of code that doesn't work!
Mark.
Joel Koltner
news:7glpj5l1a7i5nm45b...@4ax.com...
> We sell about 80% of our rev A boards, with no prototypes. Assuming
> the first unit won't work is self-fulfilling, and a good way to make
> sure the third iteration won't work either.
I agree with your philosophy John... but you do allow yourself a non-zero
number of blue wires or a couple of tack-soldered components or something on
those saleable rev. A boards too though, right?
> And my cabin automation hardware worked absolutely unaltered the first
> time!
That's great!
Joerg
I do, but much less frequently than a decade ago. I recently thought
about adding a hot air station but when thinking harder I realized that
I would use it way too little to justify the desk space it'll take.
> John Larkin does it plenty! :-)
>
But he has tons of lab space. Heck, they've even got a crane in the lab.
For lifting heavy equipment and transformers around all I've got is
Ibuprofen, in case back pain creeps up :-)
krw
Some people evidently get close enough. If you don't try to get it
right on the first time you never will, though. The problem is when
management expects to get it right on the first try, then demands it
on the second. About the fifth...
krw
What oven? We have a lot of problems with QFNs and interboard
connectors (no problems with LEDs or inductors). We had one of the IE
profs in from the local university to take a peek. He said we were
probably pushing the capabilities of our reflow oven, particularly
with RoHS crap. He also took samples of the parts to do surface
analysis (our inventory techniques need a close look too). I think
we're going to end up with a better oven. The owner doesn't want to
spring for it, but if it's really the problem it's possible that we
could double our production. He *would* like that. ;-)
Rich Webb
<jjla...@highNOTlandTHIStechnologyPART.com> wrote:
>On Thu, 31 Dec 2009 09:10:22 -0700, Don Lancaster <d...@tinaja.com>
>wrote:
>>It is NEVER right the first time.
>
>We sell about 80% of our rev A boards, with no prototypes. Assuming
>the first unit won't work is self-fulfilling, and a good way to make
>sure the third iteration won't work either.
It's really the same with hardware and software: Well-intentioned,
conscientious [*], hard-working. competent people do make mistakes and
you often can not catch your own because you see what *should* be there
not what *is* there. Code/schematic/layout reviews, formal or informal,
really are necessary. (I know I'm preaching to the choir here.)
[*] holy crap... I spelled that correctly!
--
Rich Webb Norfolk, VA
John Larkin
We do design brainstorming, informal reviews (yey, wouldja look at
this for me?) and a formal review after the board is laid out. It's
surprising how many dumb mistakes get caught, and the occasional
serious mistake.
Cose doesn't get reviewed much, because it can be changed any number
of times without pads falling off boards. It has to be tested pretty
well.
John
DJ Delorie
My way is to use a solderless breadboard, but build up sub-circuits on
home-brew PCBs. So I've got a USB adapter, MCU adapter, ethernet
socket with discretes adapter, power supply boards, etc. Homebrew can
whip up a whole panel of breadboard adapters for SOT TSSOP CSP etc in
little time and at little cost. The breadboard is for interconnecting
the modules, adding pullup/pulldowns, etc. Once the circuits are
explored this way, it goes to a PCB fab as a single final board (no
production runs for me, just a hobby) and if it doesn't work I hack it
until it does.
Here's an example of that process (scroll down to the breadboard
pics): http://www.delorie.com/electronics/alarmclock/
http://www.delorie.com/electronics/alarmclock/20070723-proto.jpg One
project, nine adapter boards (ten when you include the second OLED
connector), one breadboard.
krw
wrote:
>Joel Koltner wrote:
>> "Joerg" <inv...@invalid.invalid> wrote in message
>> news:7q2g2r...@mid.individual.net...
>>> In the professional world (product design) we go straight from
>>> simulation to schematic -> layout -> board fab -> assembly. No
>>> breadboards.
>>
>> Oh come on, even you occasionally dead bug-up (or otherwise prototype) a
>> tricky circuit that's part of a bigger product, right?
>>
>
>I do, but much less frequently than a decade ago. I recently thought
>about adding a hot air station but when thinking harder I realized that
>I would use it way too little to justify the desk space it'll take.
>
>
>> John Larkin does it plenty! :-)
>>
>
>But he has tons of lab space. Heck, they've even got a crane in the lab.
>For lifting heavy equipment and transformers around all I've got is
>Ibuprofen, in case back pain creeps up :-)
We have even better, a technician. ;-)
Joerg
If CA was a bit less onerous with rules and regs and taxes I might as
well. But ...
Raveninghorde
>On Thu, 31 Dec 2009 14:43:52 +0000, Raveninghorde
><raveninghorde@invalid> wrote:
>
SNIP
>>The new reflow oven gets commissioned on Monday which I hope will
>>reduce some of these production snags. Like LEDs die but inductors
>>don't solder.
>
>What oven? We have a lot of problems with QFNs and interboard
>connectors (no problems with LEDs or inductors). We had one of the IE
>profs in from the local university to take a peek. He said we were
>probably pushing the capabilities of our reflow oven, particularly
>with RoHS crap. He also took samples of the parts to do surface
>analysis (our inventory techniques need a close look too). I think
>we're going to end up with a better oven. The owner doesn't want to
>spring for it, but if it's really the problem it's possible that we
>could double our production. He *would* like that. ;-)
The current oven is made by TWS Automation in Italy and is pre RoHS. 2
guys can move it.
http://www.zen88234.zen.co.uk/photos/tws.jpg
It was OK after moving to RoHS but I am packing bits tighter and using
larger SMT parts such as 12mm square inductors which suck up the heat.
I had a guy going through test failures today. I saw a big pile with
the same fault. I was told the oven was killing SOT-223 transistors.
First I had heard of it. Some one will die on Monday.
When I found the LED problem all LEDs where replaced on existing
boards, about 600. They are now put on by hand which is a PITA but I
know they are reliable.
Now I know I have boards out there with suspect transistors:(
I had to get LEDs put onto aluminium backed boards elsewhere as there
was no chance of this machine coping.
The new beast, 1.3 tonnes, is a second hand Ersa Hotflow-5 made in
Germany and cost about twice as much for the new TWS one, �12k.
http://www.zen88234.zen.co.uk/photos/hotflow.jpg
Spec here:
http://www.zen88234.zen.co.uk/hf5.pdf
We had to upgrade ventillation and electrics for another �2k.
Joerg
How do you get those nice clean cuts into the copper?
Phil Hobbs
> RogerN wrote:
>> When I was in school components fit on solderless breadboards and we
>> made circuits using breadboards, power supplies, meters and
>> oscilloscopes. Many of today's components don't appear to be
>> breadboard friendly, so how is it done today?
>>
>
>
>
>> to a PC board? Or do you use surface mount to breadboard adapters? Do
>> you still use a soldering Iron to solder or paste solder and an oven?
>>
>
> simulation to schematic -> layout -> board fab -> assembly. No breadboards.
>
>
>> in only comes in MSOP or other packages that look intimidating to
>> attempt to solder.
>>
>
>
> http://www.proto-advantage.com/store/images/PRODUCTS/PA0027_0.JPG
>
> This is the variety they have but I don't know this shop, just meant as
> an example:
>
> http://www.proto-advantage.com/store/index.php?cPath=2200
>
_THE_ professional world? Joerg, Joerg, you've been holed up in that
mountain lair of yours for too long. ;)
Simulate the parts that simulators get right, do the rote stuff by rote,
but prototype the stuff you're not sure will work. It's amazing the
amount of stuff you can learn in a short time from a dead-bug prototype.
If you're just talking about laying out boards for circuit prototypes,
then I agree--you might as well try a bit harder and get it right the
first time. But trying out weird stuff, especially in mixed-technology
systems, really needs prototypes.
Besides, lots of my protos are actually small instruments that I build
in half a day and then use for years. An example is the sub-Poissonian
current source and LNA I built for my tunnel junction work--very
specific, worked great for years, took a day all told to design and
build. Good medicine.
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
55 Orchard Rd
Briarcliff Manor NY 10510
845-480-2058
hobbs at electrooptical dot net
http://electrooptical.net
alie...@gmail.com
You're getting a bunch of replies from naysayers who have gotten it
"right" the first time, but AFAICT mostly from people who have done
projects or one-offs.
In the world of production though, that's the exception rather than
the rule IME. Even if the circuit does exactly what you first
daydreamed it could do without a single glitch, even if whoever etches
the board doesn't wire a pot backwards (I've had that happen), at some
point in the product development cycle somebody will alter a spec just
enough so that just enough redesign is required that your baby needs
Frankensteining. It might be you didn't include enough LEDs for the
required "ooh, shiney" level, the case design asshat^H^Hartists
decided the air vents are in the wrong places, it has to go "boop"
instead of "beep" when junior feeds it a PB&J, or whatever.
SOMEBODY will find a reason it needs "fixing".
Mark L. Fergerson
qrk
wrote:
>
>When I was in school components fit on solderless breadboards and we made
>circuits using breadboards, power supplies, meters and oscilloscopes. Many
>of today's components don't appear to be breadboard friendly, so how is it
>done today?
>
>Is circuit design software and simulation good enough to go straight to a PC
>board? Or do you use surface mount to breadboard adapters? Do you still
>use a soldering Iron to solder or paste solder and an oven?
>
>I'm wanting to tinker with some circuits but some chips I'm interested in
>only comes in MSOP or other packages that look intimidating to attempt to
>solder.
>
>Thanks!
>
>RogerN
>
These days, I'll Spice it then go to schematic and layout. If I'm
lucky, the board is ready for production. If not, I can usually test
out most of my circuitry on the bum board.
If it's a tricky circuit, like a wierd switching power supply which
requires good layout practices, I'll do a prototype circuit board and
run it through one of the quicky circuit board places like
http://www.pcbexpress.com/ . I'll usually put a few test circuits on
the board and maybe a circuit for a personal project or piece of test
equipment on the board too.
For digital projects, my colleague will do a test run on Xilinx place
and route to catch I/O pin definition issues before committing to
layout. For high-speed digital layout, treat it like an RF analog
board.
If you understand Spice, it is a valuable tool. Bad part models can
get you in trouble. Rohm's transistor models I used were/are minus the
junction capacitances. I knew something was wrong when the response
was flat out to 10MHz.
Sometimes I'll dead bug MSOP and similar packages, but only for small
circuits. I need to be hard up to do this. You may consider surfboards
to convert surface mount to through-hole. Digikey carries these
things.
These days, I have a zoom stereo microscope ($500), hot air plate for
warming the board to 150 deg C ($155 + $30 in modifications), and a
hot air station for soldering ($185). All equipment is cheap Chinese
stuff which works fine for repair and prototyping small parts. Our
labs are equiped with Metcal soldering irons which is the place not to
skimp. I don't use solder paste on leadless packages as it is too hard
to dispense on small pads (e.g. 8-lead 1.6 x 1.6 mm packages). Easier
to apply a bump of solder to the PCB pad and coat the underbelly of
the part with flux, then hot air solder.
--
Mark
qrk
wrote:
>John Larkin wrote:
Most of our first boards go in to production without cuts and jumpers.
These are usually moderately complex boards.
Joerg
> On 12/30/2009 9:20 PM, Joerg wrote:
>> RogerN wrote:
>>> When I was in school components fit on solderless breadboards and we
>>> made circuits using breadboards, power supplies, meters and
>>> oscilloscopes. Many of today's components don't appear to be
>>> breadboard friendly, so how is it done today?
>>>
>>
>> I even used bare thumbtacks on plywood for solder posts back then.
>>
>>
>>> Is circuit design software and simulation good enough to go straight
>>> to a PC board? Or do you use surface mount to breadboard adapters? Do
>>> you still use a soldering Iron to solder or paste solder and an oven?
>>>
>>
>> In the professional world (product design) we go straight from
>> simulation to schematic -> layout -> board fab -> assembly. No
>> breadboards.
>>
>>
>>> I'm wanting to tinker with some circuits but some chips I'm interested
>>> in only comes in MSOP or other packages that look intimidating to
>>> attempt to solder.
>>>
>>
>> Well, for hobbyists or one-off designs there is help but not very cheap:
>>
>> http://www.proto-advantage.com/store/images/PRODUCTS/PA0027_0.JPG
>>
>> This is the variety they have but I don't know this shop, just meant as
>> an example:
>>
>> http://www.proto-advantage.com/store/index.php?cPath=2200
>>
>
> _THE_ professional world? Joerg, Joerg, you've been holed up in that
> mountain lair of yours for too long. ;)
>
Now, now, we do have a modern feed store in this here town whar we're
gitten them alfalfa bales and all that, and they even use a computation
machine :-)
> Simulate the parts that simulators get right, do the rote stuff by rote,
> but prototype the stuff you're not sure will work. It's amazing the
> amount of stuff you can learn in a short time from a dead-bug prototype.
>
> If you're just talking about laying out boards for circuit prototypes,
> then I agree--you might as well try a bit harder and get it right the
> first time. But trying out weird stuff, especially in mixed-technology
> systems, really needs prototypes.
>
Ok, I did build a breadboard for my first noise-critical fiber-optics
front end but that was more because the client really wanted that done.
I ended up not changing a thing on there and going straight to a
multi-channel layout. Since it has digital delay controls with SPI and
stuff it (almost) counts as mixed signal.
> Besides, lots of my protos are actually small instruments that I build
> in half a day and then use for years. An example is the sub-Poissonian
> current source and LNA I built for my tunnel junction work--very
> specific, worked great for years, took a day all told to design and
> build. Good medicine.
>
One-off things I also often build on experimental board. I am not a
great friend of the dead-bug style, preferring Vector board with a
ground plane. That's harder to find these days so I stocked up. Many
things go into those little Pomona boxes that end up riding on the back
of a coax connector. All good medicine, but at least I can put a shiny
aluminum lid on it so the clients don't see the wire ball inside my probes.
Joerg
[...]
> These days, I have a zoom stereo microscope ($500), hot air plate for
> warming the board to 150 deg C ($155 + $30 in modifications), and a
> hot air station for soldering ($185). All equipment is cheap Chinese
> stuff which works fine for repair and prototyping small parts. Our
> labs are equiped with Metcal soldering irons which is the place not to
> skimp. I don't use solder paste on leadless packages as it is too hard
> to dispense on small pads (e.g. 8-lead 1.6 x 1.6 mm packages). Easier
> to apply a bump of solder to the PCB pad and coat the underbelly of
> the part with flux, then hot air solder.
>
How do you get the flux back outta there?
Tim Williams
to breadboarding the bits I don't know and CADing everything else.
Motivation: even for one-offs, it's easier to move components around in CAD
space than desoldering and moving things in real life. Layout is a lot
easier when you already know where everything goes, the error rate is lower,
and it simply looks better.
Two boards so far, fairly large as hobby boards go (~500 holes), one worked
perfectly first time (a switching power supply similar to your average
computer PSU). The other had a few errors I missed on schematic entry, and
a few other errors due to negligence. Nothing big, some flying wires and
cut traces fixed it. 99% was fine, so it was a worthwhile prototype.
Tim
--
Deep Friar: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms
"RogerN" <re...@midwest.net> wrote in message
news:ROudnXLvg9-Tm6HW...@earthlink.com...
>
> When I was in school components fit on solderless breadboards and we made
> circuits using breadboards, power supplies, meters and oscilloscopes.
> Many of today's components don't appear to be breadboard friendly, so how
> is it done today?
>
> Is circuit design software and simulation good enough to go straight to a
> PC board? Or do you use surface mount to breadboard adapters? Do you
> still use a soldering Iron to solder or paste solder and an oven?
>
> I'm wanting to tinker with some circuits but some chips I'm interested in
> only comes in MSOP or other packages that look intimidating to attempt to
> solder.
>
> Thanks!
>
> RogerN
>
>
Joerg
Very common situation when you are a consultant. New client, first
article should have shipped a couple months ago but it still doesn't
work. Everyone shaking in their boots. _Then_ your phone rings,
agreement is signed same day, you call off any and all birthday parties
and whatnot and you've got exactly one shot to get it right.
> ...then demands it on the second. About the fifth...
They'd have me over the barrel :-)
Joel Koltner
likelihood of hardware needing multiple board spins having a lot to do with
the attitude of the designers is very significant and can lead to quicker
deliveries and low costs. Additionally, you need someone decent in management
to minimize the number of times some guy in marketing wants you to move an LED
left 1" and change it from green to blue.
The other thing that I don't imagine is necessarily obvious to people who
don't read the group regularly is the different areas people here are working
in: AIUI, John is doing very-high-speed time-domain stuff (along with a
healthy dose of FPGAs and CPUs to manage it all), Joerg does a whole bunch of
different analog things (and a few microcontroller bits) but generally below
1GHz, and others are doing very fancy digital boards. The difficulty in
getting a board 100% correct on the first go-around -- at least for me --
climbs noticeably as one switches from "almost all digital" to "almost all
analog" and from the MHz range to the GHz range. And of course then you throw
in all the extra bits above and beyond "does it just work?" that Joerg deals
with -- EMI/EMC, agency approvals, etc.
---Joel
Joerg
Did it on a recent project: Client wanted five units to kick the tires.
The difference between buying 5 bare boards and 50 boards was miniscule.
So now they can make 45 more unit and the PCBs will be almost free, they
just have to pay for parts, stuffing and testing.
Joerg
>>
>
> It is NEVER right the first time.
>
It is, too :-)
Nico Coesel
>On Thu, 31 Dec 2009 06:25:56 -0800 (PST), MooseFET
><kens...@rahul.net> wrote:
>
>>On Dec 30, 6:01�pm, "RogerN" <re...@midwest.net> wrote:
>>> When I was in school components fit on solderless breadboards and we made
>>> circuits using breadboards, power supplies, meters and oscilloscopes. �Many
>>> of today's components don't appear to be breadboard friendly, so how is it
>>> done today?
>>>
>>> Is circuit design software and simulation good enough to go straight to a PC
>>> board? �Or do you use surface mount to breadboard adapters? �Do you still
>>> use a soldering Iron to solder or paste solder and an oven?
>>>
>>> I'm wanting to tinker with some circuits but some chips I'm interested in
>>> only comes in MSOP or other packages that look intimidating to attempt to
>>> solder.
>>
>>I use ExpressPCB to make boards for parts of the design. Things like
>>power supplies are made as a PCB with connectors that are wired to the
>>other boards. I use 1206 parts and put in some extra parts and layout
>>such that cuts and jumps are easy(ish) to do.
>>
>>>
>>> Thanks!
>>>
>>> RogerN
>
>Think. Read data sheets. Think. CAD. Make on production line.
>
>Pcb design rarely takes longer than a lash up on strip board or
>whatever and always works better.
>
>Very occasionally I have lashed up a small part of a design but I
>almost always regret the waste of time.
The truth lies somewhere in between. I use whatever seems most handy
given the situation. For analog I use simulation a lot but it always
gets prototyped. SMD components either end up as a dead bug on
prototyping board or a small dedicated PCB. RF and power means having
a small PCB made. Sometimes I like to try things like a new
microcontroller. I usually make universal (=a load of via's to connect
wires to) boards out of such a project so they can serve as a
kickstart for prototyping other projects.
--
Failure does not prove something is impossible, failure simply
indicates you are not using the right tools...
nico@nctdevpuntnl (punt=.)
--------------------------------------------------------------
Falk Willberg
> RogerN wrote:
...
>> Is circuit design software and simulation good enough to go straight
>> to a PC board? Or do you use surface mount to breadboard adapters?
>> Do you still use a soldering Iron to solder or paste solder and an oven?
>>
> In the professional world (product design) we go straight from
> simulation to schematic -> layout -> board fab -> assembly. No breadboards.
How do you deal with "Locate capacitor as *close* *as* *possible* to the
regulator output and ground pins"? (I know, you try to avoid using LDOs)
How do you deal with incorrect/optimistic data sheets?
I had more than one sensor (mostyl accelerometer/magnetometer), that
behaved different from what the manufacturer hoped it would.
Another problem is, that errata are written *after* the error was found.
I prefer to have seen a design working as expected.
But I am only a software guy, who knows where the soldering iron's hot
end is, anyway ;-)
>> I'm wanting to tinker with some circuits but some chips I'm interested
>> in only comes in MSOP or other packages that look intimidating to
>> attempt to solder.
> Well, for hobbyists or one-off designs there is help but not very cheap:
>
> http://www.proto-advantage.com/store/images/PRODUCTS/PA0027_0.JPG
That *is* cheap.
> This is the variety they have but I don't know this shop, just meant as
> an example:
>
> http://www.proto-advantage.com/store/index.php?cPath=2200
But I prefer etching my PCBs to using breakout boards. Can save time.
Guten Rutsch ins neue Jahr,
Falk
--
http://consult42.com/
http://falk-willberg.de/loetkunst.html
Jan Panteltje
<d...@delorie.com> wrote in <xnws039...@delorie.com>:
>project, nine adapter boards (ten when you include theftp://panteltje.com/pub/z80/graphics_card_top.jpg second OLED
>connector), one breadboard.
Real man use no PeeSeeBee:
ftp://panteltje.com/pub/z80/graphics_card_top.jpg
ftp://panteltje.com/pub/z80/graphics_card_bottom.jpg
:-)
Jan Panteltje
"nu...@bid.nes" <alie...@gmail.com> wrote in
<06c2a0da-7756-4040...@a6g2000yqm.googlegroups.com>:
> In the world of production though, that's the exception rather than
>the rule IME. Even if the circuit does exactly what you first
>daydreamed it could do without a single glitch, even if whoever etches
>the board doesn't wire a pot backwards (I've had that happen), at some
>point in the product development cycle somebody will alter a spec just
>enough so that just enough redesign is required that your baby needs
>Frankensteining. It might be you didn't include enough LEDs for the
>required "ooh, shiney" level, the case design asshat^H^Hartists
>decided the air vents are in the wrong places, it has to go "boop"
>instead of "beep" when junior feeds it a PB&J, or whatever.
>
> SOMEBODY will find a reason it needs "fixing".
>
>
> Mark L. Fergerson
Yes I had that happen, where the specs changed after each council meeting..
Something to do with fire rules.
But I did not have the board made until they stopped changing.
Joerg
> Joerg schrieb:
>> RogerN wrote:
>
> ...
>
>>> Is circuit design software and simulation good enough to go straight
>>> to a PC board? Or do you use surface mount to breadboard adapters?
>>> Do you still use a soldering Iron to solder or paste solder and an oven?
>>>
>> In the professional world (product design) we go straight from
>> simulation to schematic -> layout -> board fab -> assembly. No breadboards.
>
> How do you deal with "Locate capacitor as *close* *as* *possible* to the
> regulator output and ground pins"? (I know, you try to avoid using LDOs)
>
I grew up with RF-style design and EMC jobs so that really isn't a
problem for me. The layouter I often use is also a bit on the older side
and very experienced so I rarely have to tell him what needs special
attention. Plus we are politically on the same wavelength which helps :-))
In my module specs there is always a section called "Layout Guidance".
That has all the caution notes in there. And no, I do not use LDOs.
> How do you deal with incorrect/optimistic data sheets?
> I had more than one sensor (mostyl accelerometer/magnetometer), that
> behaved different from what the manufacturer hoped it would.
>
> Another problem is, that errata are written *after* the error was found.
>
With reputable manufacturers that is rare but I had one of those happen
recently. LT6700 series comparators. Turns out there's a bug on those in
that the reference shoots way up after applying power and then settles
after 500usec. In a nutshell, those things just don't work right until
500usec after power-up. The simulator doesn't show this and I think I
was the first customer to find out. By sheer luck I had my design done
in a way that I could muffle this. But other than that LTC is a great
company, with excellent engineering support.
> I prefer to have seen a design working as expected.
> But I am only a software guy, who knows where the soldering iron's hot
> end is, anyway ;-)
>
I am a hardware guy who sometimes finds a workaround solution in
software and then says "Oh, it was just software" :-)
>>> I'm wanting to tinker with some circuits but some chips I'm interested
>>> in only comes in MSOP or other packages that look intimidating to
>>> attempt to solder.
>> Well, for hobbyists or one-off designs there is help but not very cheap:
>>
>> http://www.proto-advantage.com/store/images/PRODUCTS/PA0027_0.JPG
>
> That *is* cheap.
>
Yeah, in Euros ...
I often design with chips like the LM3478. When you add a $2.50 adapter
to each $1 chip it kind of adds up. I can get two bottles of top notch
Porter for that.
>> This is the variety they have but I don't know this shop, just meant as
>> an example:
>>
>> http://www.proto-advantage.com/store/index.php?cPath=2200
>
> http://www.seeedstudio.com/depot/prototyping-with-smd-chips-stamp-bundle-pad2pad-p-137.html?cPath=64_33
>
Nice. Very smart design with the sliding scale QFP pattern. But being an
analog guy I usually need TSSOP and MSOP.
> But I prefer etching my PCBs to using breakout boards. Can save time.
>
> Guten Rutsch ins neue Jahr,
Same to you. And careful with your Enfield motorcycle on the ice and snow.
Joerg
<GASP>
I think I am going to get sick ...
Jim Thompson
wrote:
SOS: System on a ..... shingle ?:-)
...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
"You cannot help the poor by destroying the rich. You cannot
strengthen the weak by weakening the strong. You cannot bring
about prosperity by discouraging thrift. You cannot lift the wage
earner up by pulling the wage payer down. You cannot further the
brotherhood of man by inciting class hatred. You cannot build
character and courage by taking away people's initiative and
independence. You cannot help people permanently by doing for
them, what they could and should do for themselves."
-Abraham Lincoln
krw
wrote:
The real problem is when they want it fixed, without changing
anything. That's when the real churn starts. Compliance added
another to a recent design because nothing could be changed in a
previous "fix". Risk avoidance can itself be risky.
krw
"Projects?" "One-offs?"
> In the world of production though, that's the exception rather than
>the rule IME. Even if the circuit does exactly what you first
>daydreamed it could do without a single glitch, even if whoever etches
>the board doesn't wire a pot backwards (I've had that happen), at some
Backwards pots are code changes. ;-) (we use shaft encoders for
pots).
>point in the product development cycle somebody will alter a spec just
>enough so that just enough redesign is required that your baby needs
Spec changes don't count. That's management's fault. ;-) You do
point out one of the main pitfalls, though. A good spec is critical
to getting success out of the first board. Changing the rules after
the game starts is cheating.
>Frankensteining. It might be you didn't include enough LEDs for the
>required "ooh, shiney" level, the case design asshat^H^Hartists
>decided the air vents are in the wrong places,
IME the sheet metal always gets done before the circuits. The sheet
metal fixes the number of blinkin' lights and fancy knobs pretty well.
>it has to go "boop"
>instead of "beep" when junior feeds it a PB&J, or whatever.
Code.
> SOMEBODY will find a reason it needs "fixing".
"Whenever more than one person is involved in a screwup, blame will
never be placed." Or "The first to blink, loses." BTDT, it's no fun.
Jan Panteltje
<inv...@invalid.invalid> wrote in <7q4ocp...@mid.individual.net>:
>> Real man use no PeeSeeBee:
>> ftp://panteltje.com/pub/z80/graphics_card_top.jpg
>> ftp://panteltje.com/pub/z80/graphics_card_bottom.jpg
>> :-)
>>
>
><GASP>
>
>I think I am going to get sick ...
Have to point out that that worked without a single problem for > 10 years.
And it will likely still work if the EPROM has not lost data.
But it has been superseded by better tech.
You are not afraid of soldering some wires no?
John Larkin
wrote:
Just x-acto. The magic trick is to then rub it hard with a Scotchbrite
pad. That removes the burrs.
John
Joerg
Wow, that is a precise X-acto cut.
Falk Willberg
> On a sunny day (Thu, 31 Dec 2009 14:54:10 -0800) it happened Joerg
> <inv...@invalid.invalid> wrote in <7q4ocp...@mid.individual.net>:
>>> Real man use no PeeSeeBee:
>>> ftp://panteltje.com/pub/z80/graphics_card_top.jpg
Why did I know that I would see an 6845 when it completely loaded?
>>> ftp://panteltje.com/pub/z80/graphics_card_bottom.jpg
>>> :-)
>>>
>> <GASP>
>>
>> I think I am going to get sick ...
>
> Have to point out that that worked without a single problem for > 10 years.
That's the annoying thing with this kind of "implementation": It often
just works.
> And it will likely still work if the EPROM has not lost data.
> But it has been superseded by better tech.
> You are not afraid of soldering some wires no?
My first CP/M computer was made the same way, but I used enameled copper
wire[0] on the solder side only. My brother wrote his first 100+ job
applications on this beast (Wordstar + DBase).
Falk
[0]I still use it: http://falk-willberg.de/LiPo-Lader-web.JPG (the 5
"thick" wires)
Joerg
Not at all, but I use thin copper-enameled wires and run them in orderly
fashion :-)
MooseFET
It is very hard to hook a spice model to the real transducers.
Making a spice model of the transducer isn't so easy when it is
pushing the limits of physics and you have to assume that the physics
guy got it exactly right when he did his equations.
Very few op-amps have truly accurate spice models. They don't cover
things like the recovery from hitting the rails or slew rate limits.
They almost all beam electrons in from some other universe.
Models of inductors are not super accurate. Even the ones that cover
saturation are only approximations.
If you have to write software to go with the hardware, it is very nice
to debug on something like the real hardware.
Jan Panteltje
<inv...@invalid.invalid> wrote in <7q4rqd...@mid.individual.net>:
>Jan Panteltje wrote:
>> On a sunny day (Thu, 31 Dec 2009 14:54:10 -0800) it happened Joerg
>> <inv...@invalid.invalid> wrote in <7q4ocp...@mid.individual.net>:
>>>> Real man use no PeeSeeBee:
>>>> ftp://panteltje.com/pub/z80/graphics_card_top.jpg
>>>> ftp://panteltje.com/pub/z80/graphics_card_bottom.jpg
>>>> :-)
>>>>
>>> <GASP>
>>>
>>> I think I am going to get sick ...
>>
>> Have to point out that that worked without a single problem for > 10 years.
>> And it will likely still work if the EPROM has not lost data.
>> But it has been superseded by better tech.
>> You are not afraid of soldering some wires no?
>
>
>Not at all, but I use thin copper-enameled wires and run them in orderly
>fashion :-)
Bu the vapour of the enamel is poisenous :-).
I tried that stuff, it stinks.
Normally I use flat cable:
ftp://panteltje.com/pub/z80/sound_card_bottom.jpg
ftp://panteltje.com/pub/z80/soundcard_top.jpg
That flat vertical thing is a R2R network, the DAC.
Top right an electret mike,
Bottom right a DC-DC converter for the negative voltage of the TIL084s
Audio amp: LM380,
ADC: ADC804
SAA1099 for sound effects... (did not really use that, used wave tables).
the resistors and caps in the IC sockets are part of the anti-aliasing filters.
Also wrote a sound editor for it, all 8 bits of course.
Nico Coesel
>Jan Panteltje wrote:
>> On a sunny day (Thu, 31 Dec 2009 14:54:10 -0800) it happened Joerg
>> <inv...@invalid.invalid> wrote in <7q4ocp...@mid.individual.net>:
>>>> Real man use no PeeSeeBee:
>>>> ftp://panteltje.com/pub/z80/graphics_card_top.jpg
>>>> ftp://panteltje.com/pub/z80/graphics_card_bottom.jpg
>>>> :-)
>>>>
>>> <GASP>
>>>
>>> I think I am going to get sick ...
>>
>> Have to point out that that worked without a single problem for > 10 years.
>> And it will likely still work if the EPROM has not lost data.
>> But it has been superseded by better tech.
>> You are not afraid of soldering some wires no?
>
>
>Not at all, but I use thin copper-enameled wires and run them in orderly
>fashion :-)
I think I have similar boards somewhere but enamel wire is the way to
go.
Jan Panteltje
<Fawegl...@falk-willberg.de> wrote in
<hhjd5b$lco$1...@news2.open-news-network.org>:
Yes, same here, I uses strands from strands from flat cable, no isolation to burn.
Nico Coesel
>On Thu, 31 Dec 2009 12:34:12 -0600, krw <k...@att.bizzzzzzzzzzz> wrote:
>
>>On Thu, 31 Dec 2009 14:43:52 +0000, Raveninghorde
>><raveninghorde@invalid> wrote:
>>
>
>SNIP
>
>>>The new reflow oven gets commissioned on Monday which I hope will
>>>reduce some of these production snags. Like LEDs die but inductors
>>>don't solder.
>>
>>What oven? We have a lot of problems with QFNs and interboard
>>connectors (no problems with LEDs or inductors). We had one of the IE
>>profs in from the local university to take a peek. He said we were
>>probably pushing the capabilities of our reflow oven, particularly
>>with RoHS crap. He also took samples of the parts to do surface
>>analysis (our inventory techniques need a close look too). I think
>>we're going to end up with a better oven. The owner doesn't want to
>>spring for it, but if it's really the problem it's possible that we
>>could double our production. He *would* like that. ;-)
>
>The current oven is made by TWS Automation in Italy and is pre RoHS. 2
>guys can move it.
>
>http://www.zen88234.zen.co.uk/photos/tws.jpg
>
>It was OK after moving to RoHS but I am packing bits tighter and using
>larger SMT parts such as 12mm square inductors which suck up the heat.
>
>I had a guy going through test failures today. I saw a big pile with
>the same fault. I was told the oven was killing SOT-223 transistors.
>First I had heard of it. Some one will die on Monday.
Soldering with an oven is a black art. What sometimes works is to send
a bare PCB throught the machine at the beginning of a batch. This
helps to level the temperatures. It should be possible to solder any
board, but it takes a lot of finetuning.
Joerg
Yup. It is very hard to model backing materials, acoustic matching
layers, crosstalk and all that. This either needs to be characterized
via some other software or measured.
One attempt in doing it mathematically ended with a first generation
Pentium processor going tchk ... *PHUT*.
[...]
Joerg
> On a sunny day (Thu, 31 Dec 2009 15:52:38 -0800) it happened Joerg
> <inv...@invalid.invalid> wrote in <7q4rqd...@mid.individual.net>:
>
>> Jan Panteltje wrote:
>>> On a sunny day (Thu, 31 Dec 2009 14:54:10 -0800) it happened Joerg
>>> <inv...@invalid.invalid> wrote in <7q4ocp...@mid.individual.net>:
>>>>> Real man use no PeeSeeBee:
>>>>> ftp://panteltje.com/pub/z80/graphics_card_top.jpg
>>>>> ftp://panteltje.com/pub/z80/graphics_card_bottom.jpg
>>>>> :-)
>>>>>
>>>> <GASP>
>>>>
>>>> I think I am going to get sick ...
>>> Have to point out that that worked without a single problem for > 10 years.
>>> And it will likely still work if the EPROM has not lost data.
>>> But it has been superseded by better tech.
>>> You are not afraid of soldering some wires no?
>>
>> Not at all, but I use thin copper-enameled wires and run them in orderly
>> fashion :-)
>
> Bu the vapour of the enamel is poisenous :-).
> I tried that stuff, it stinks.
Roll yourself a Van Nelle Halfzwaar, light up, and all the smell is
muffled :-)
> Normally I use flat cable:
> ftp://panteltje.com/pub/z80/sound_card_bottom.jpg
What's that ugly big silvery thing on the right?
> ftp://panteltje.com/pub/z80/soundcard_top.jpg
Looks like the cat peed over the speaker :-)
> That flat vertical thing is a R2R network, the DAC.
> Top right an electret mike,
> Bottom right a DC-DC converter for the negative voltage of the TIL084s
> Audio amp: LM380,
> ADC: ADC804
> SAA1099 for sound effects... (did not really use that, used wave tables).
> the resistors and caps in the IC sockets are part of the anti-aliasing filters.
> Also wrote a sound editor for it, all 8 bits of course.
>
Main thing is, it works.
Falk Willberg
> <snip> Falk <snip> wrote:
>> [0]I still use it: http://falk-willberg.de/LiPo-Lader-web.JPG (the 5
>> "thick" wires)
>
> Yes, same here, I uses strands from strands from flat cable, no isolation to burn.
Very useful. The remaining flat cable makes a good handle. See the other
wires in the above link.
Happy new year,
Falk
consult42.com/tmp/fireworks2010-0.5MB.mpg
consult42.com/tmp/fireworks2010-11MB.mpg
Falk Willberg
> Jan Panteltje wrote:
...
> Roll yourself a Van Nelle Halfzwaar, light up, and all the smell is
> muffled :-)
Half... Pah!
...
>> ftp://panteltje.com/pub/z80/sound_card_bottom.jpg
>
> What's that ugly big silvery thing on the right?
Looks like McGuyver^WDuck-Tape
Falk
Joerg
> Joerg schrieb:
>> Jan Panteltje wrote:
>
> ...
>
>> Roll yourself a Van Nelle Halfzwaar, light up, and all the smell is
>> muffled :-)
>
> Half... Pah!
>
Oh, a real connoisseur :-)
Gauloises self-rolled is pretty good. But that was a long time ago.
> ...
>
>>> ftp://panteltje.com/pub/z80/sound_card_bottom.jpg
>> What's that ugly big silvery thing on the right?
>
> Looks like McGuyver^WDuck-Tape
>
The top, yes, but there is some serious oozing underneath.
Jan Panteltje
<inv...@invalid.invalid> wrote in <7q4ti4...@mid.individual.net>:
>> Normally I use flat cable:
>> ftp://panteltje.com/pub/z80/sound_card_bottom.jpg
>
>
>What's that ugly big silvery thing on the right?
>
>
>> ftp://panteltje.com/pub/z80/soundcard_top.jpg
>
>
>Looks like the cat peed over the speaker :-)
It is 'bison kit', or translated 'Bison Glue'.
Lots of it to keep that speaker fixed, had to re-glue it a couple of times.
Maybe Bison Kit is made of Bison pee, I really do not know what is in it,
but it is a very good glue for general purpose application.
Jan Panteltje
<inv...@invalid.invalid> wrote in <7q4uba...@mid.individual.net>:
>Falk Willberg wrote:
>> Joerg schrieb:
>>> Jan Panteltje wrote:
>>
>> ...
>>
>>> Roll yourself a Van Nelle Halfzwaar, light up, and all the smell is
>>> muffled :-)
>>
>> Half... Pah!
>>
>
>Oh, a real connoisseur :-)
>
>Gauloises self-rolled is pretty good. But that was a long time ago.
>
>> ...
>>
>>>> ftp://panteltje.com/pub/z80/sound_card_bottom.jpg
>>> What's that ugly big silvery thing on the right?
>>
>> Looks like McGuyver^WDuck-Tape
>>
>
>The top, yes, but there is some serious oozing underneath.
The idea a an acoustic short,
As the speaker front side is against the PCB, and the PCB has holes,
the holes most be closed to prevent an acoustic short.
the speaher radiates from it's back, which is on top.
I guess I could have soldered the holes closed.
Jan Panteltje
<Fawegl...@falk-willberg.de> wrote in
<hhjfai$m6f$1...@news2.open-news-network.org>:
The same.
Nice.
I had 2 cameras running for the fireworks,
1 320x240 @60 fps, and 1 640x480 @50fps
About 90 minutes material altogether,
need to look at it and edit out the useful parts.
Joerg
It's too long ago but AFAIR we used something like Araldit in the
Netherlands back in my days. The spelling could be wrong but it held on
very well. It didn't leave such nasty residue unless you let it ooze all
over the place. Ok, it wasn't exactly the Netherlands but the province
of Zuid Limburg which you guys considered a foreign country.
John Larkin
<pNaonSt...@yahoo.com> wrote:
>On a sunny day (31 Dec 2009 14:12:03 -0500) it happened DJ Delorie
><d...@delorie.com> wrote in <xnws039...@delorie.com>:
>
>>
>>My way is to use a solderless breadboard, but build up sub-circuits on
>>home-brew PCBs. So I've got a USB adapter, MCU adapter, ethernet
>>socket with discretes adapter, power supply boards, etc. Homebrew can
>>whip up a whole panel of breadboard adapters for SOT TSSOP CSP etc in
>>little time and at little cost. The breadboard is for interconnecting
>>the modules, adding pullup/pulldowns, etc. Once the circuits are
>>explored this way, it goes to a PCB fab as a single final board (no
>>production runs for me, just a hobby) and if it doesn't work I hack it
>>until it does.
>>
>>Here's an example of that process (scroll down to the breadboard
>>pics): http://www.delorie.com/electronics/alarmclock/
>>http://www.delorie.com/electronics/alarmclock/20070723-proto.jpg One
>>project, nine adapter boards (ten when you include theftp://panteltje.com/pub/z80/graphics_card_top.jpg second OLED
>>connector), one breadboard.
>
>Real man use no PeeSeeBee:
> ftp://panteltje.com/pub/z80/graphics_card_top.jpg
> ftp://panteltje.com/pub/z80/graphics_card_bottom.jpg
>:-)
>
ACK! We were going out for beer and burgers, but you just killed my
appetite.
This is more like it. The bottom board is my one-off signal
conditioner/relay driver. And I built a spare.
ftp://jjlarkin.lmi.net/Auto_plate.jpg
John
MooseFET
Audio:
It is doubly troublesome when you are designing for things that need
to work over a range of pressures. The mechanical characteristics of
materials change with stress. Resonant frequencies tend to move about
and some things make noise for unexpected reasons.
Electromagnetic:
The electrical properties of soil are all over the map. Check out
Bruce Candy's patent on how to reject magnetic soils in a metal
detector some time. It actually works (mostly kind of)
mi...@sushi.com
> Phil Hobbs wrote:
> > On 12/30/2009 9:20 PM, Joerg wrote:
> >> RogerN wrote:
> >>> When I was in school components fit on solderless breadboards and we
> >>> made circuits using breadboards, power supplies, meters and
> >>> oscilloscopes. Many of today's components don't appear to be
> >>> breadboard friendly, so how is it done today?
>
>
> >>> Is circuit design software and simulation good enough to go straight
> >>> to a PC board? Or do you use surface mount to breadboard adapters? Do
> >>> you still use a soldering Iron to solder or paste solder and an oven?
>
> >> simulation to schematic -> layout -> board fab -> assembly. No
> >> breadboards.
>
> >>> I'm wanting to tinker with some circuits but some chips I'm interested
> >>> in only comes in MSOP or other packages that look intimidating to
> >>> attempt to solder.
>
>
> >>http://www.proto-advantage.com/store/images/PRODUCTS/PA0027_0.JPG
>
> >> This is the variety they have but I don't know this shop, just meant as
> >> an example:
>
> >>http://www.proto-advantage.com/store/index.php?cPath=2200
>
> > _THE_ professional world? Joerg, Joerg, you've been holed up in that
> > mountain lair of yours for too long. ;)
>
> Now, now, we do have a modern feed store in this here town whar we're
> gitten them alfalfa bales and all that, and they even use a computation
> machine :-)
>
> > Simulate the parts that simulators get right, do the rote stuff by rote,
> > but prototype the stuff you're not sure will work. It's amazing the
> > amount of stuff you can learn in a short time from a dead-bug prototype.
>
> > If you're just talking about laying out boards for circuit prototypes,
> > then I agree--you might as well try a bit harder and get it right the
> > first time. But trying out weird stuff, especially in mixed-technology
> > systems, really needs prototypes.
>
> Ok, I did build a breadboard for my first noise-critical fiber-optics
> front end but that was more because the client really wanted that done.
> I ended up not changing a thing on there and going straight to a
> multi-channel layout. Since it has digital delay controls with SPI and
> stuff it (almost) counts as mixed signal.
>
> > Besides, lots of my protos are actually small instruments that I build
> > in half a day and then use for years. An example is the sub-Poissonian
> > current source and LNA I built for my tunnel junction work--very
> > specific, worked great for years, took a day all told to design and
> > build. Good medicine.
>
> One-off things I also often build on experimental board. I am not a
> great friend of the dead-bug style, preferring Vector board with a
> ground plane. That's harder to find these days so I stocked up. Many
> things go into those little Pomona boxes that end up riding on the back
> of a coax connector. All good medicine, but at least I can put a shiny
> aluminum lid on it so the clients don't see the wire ball inside my probes.
>
> --
> Regards, Joerg
>
> http://www.analogconsultants.com/
>
> "gmail" domain blocked because of excessive spam.
> Use another domain or send PM.
Vector board is insanely priced. I buy it up at flea markets when I
find good deals and nibble out small pieces for circuits to conserve
it. I think if I had to pay real prices for vectorboard, I'd use the
on-line PCB manufacturers. I dead bug too.
Funny nobody mentioned using a board grinder.
John Larkin
Live bug is easier to visualize. And if you work on copperclad, you
can bend ungrounded pins out horizontally and solder the groudable
pins directly to the plane.
Kapton tape is great, too, when working on copperclad.
John
Spehro Pefhany
<d...@tinaja.com> wrote:
>John Larkin wrote:
>> On Thu, 31 Dec 2009 14:01:44 -0000, "markp" <map.n...@f2s.com>
>> wrote:
>>
>>> "RogerN" <re...@midwest.net> wrote in message
>>> news:ROudnXLvg9-Tm6HW...@earthlink.com...
>>>> When I was in school components fit on solderless breadboards and we made
>>>> circuits using breadboards, power supplies, meters and oscilloscopes.
>>>> Many of today's components don't appear to be breadboard friendly, so how
>>>> is it done today?
>>>>
>>>> Is circuit design software and simulation good enough to go straight to a
>>>> PC board? Or do you use surface mount to breadboard adapters? Do you
>>>> still use a soldering Iron to solder or paste solder and an oven?
>>>>
>>>> I'm wanting to tinker with some circuits but some chips I'm interested in
>>>> only comes in MSOP or other packages that look intimidating to attempt to
>>>> solder.
>>>>
>>>> Thanks!
>>>>
>>>> RogerN
>>>>
>>>>
>>> I tend to design a PCB with CAD software then have prototype PCBs made.
>>> There are several companies out there who do 'pooling', i.e. they amalgamate
>>> many designs onto one PCB, that way you end up only paying a small fraction
>>> of the tooling cost of the PCB. Some companies can handle 6 layer boards
>>> with this process. Example in the UK is PCB Snap from Spirit Circuits
>>> (www.spiritcircuits.com).
>>>
>>> This can be quite cost effectve for producing protptypes that are as close
>>> to the final product as practicable.
>>
>> Why not go for the real thing, first time? If you get it right, you
>> can sell it.
>>
>> John
>>
>
>It is NEVER right the first time.
Keep firing people who have that attitude and it eventually will be!
Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
sp...@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com
mi...@sushi.com
<jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
> On Thu, 31 Dec 2009 19:28:42 -0800 (PST), "m...@sushi.com"
The backwards pinout is an issue. I sharpie the pin numbers after I
mount the dead bug.
David L. Jones
>
>> When I was in school components fit on solderless breadboards and we
>> made circuits using breadboards, power supplies, meters and
>> oscilloscopes. Many of today's components don't appear to be
>> breadboard friendly, so how is it done today?
>>
>> to a PC board? Or do you use surface mount to breadboard adapters?
>> Do you still use a soldering Iron to solder or paste solder and an
>> oven?
>>
>> interested in only comes in MSOP or other packages that look
>> intimidating to attempt to solder.
>>
>
> You can stock up on a LOT of tiny SMT to through-hole boards and just
> solder the SMT onto those and drop them into your solderless
> breadboard or else wire-wrap sockets. Perhaps someone on the web
> sells these in batches or else has a kind of nifty board with a bunch
> of SMT outlines to through-holes on them and you can use that? Some
> companies sell these expensive adapter boards, too. But they usually
> aren't very cheap. Dead-bug point-to-point is another method.
For those interested in dead-bug prototyping, see my video blog:
http://www.eevblog.com/2009/08/06/eevblog-23-gsm-mobile-phone-audio-design/
Dave.
--
---------------------------------------------
Check out my Electronics Engineering Video Blog & Podcast:
http://www.eevblog.com
Jan Panteltje
<inv...@invalid.invalid> wrote in <7q512e...@mid.individual.net>:
>> It is 'bison kit', or translated 'Bison Glue'.
>> Lots of it to keep that speaker fixed, had to re-glue it a couple of times.
>> Maybe Bison Kit is made of Bison pee, I really do not know what is in it,
>> but it is a very good glue for general purpose application.
>
>
>It's too long ago but AFAIR we used something like Araldit in the
>Netherlands back in my days. The spelling could be wrong but it held on
>very well. It didn't leave such nasty residue unless you let it ooze all
>over the place. Ok, it wasn't exactly the Netherlands but the province
>of Zuid Limburg which you guys considered a foreign country.
>
>--
>Regards, Joerg
Araldit is a 2 component glue.
It sets faster when heated too.
Bison kit is a one component, apply to both sides, wait 3 minutes, push together glue
from a tube.
Bison kit stays a bit soft or flexible, while Araldit becomes stone hard.
Jan Panteltje
<jjla...@highNOTlandTHIStechnologyPART.com> wrote in
<q9mqj5dsgr3mvime8...@4ax.com>:
>>Real man use no PeeSeeBee:
>> ftp://panteltje.com/pub/z80/graphics_card_top.jpg
>> ftp://panteltje.com/pub/z80/graphics_card_bottom.jpg
>>:-)
>>
>
>ACK! We were going out for beer and burgers, but you just killed my
>appetite.
>
>This is more like it. The bottom board is my one-off signal
>conditioner/relay driver. And I built a spare.
>
>ftp://jjlarkin.lmi.net/Auto_plate.jpg
It looks very nice, but those screw terminals...
I have had some molten ones, probably because I used those at 10 A.
Am I imagining it, or are there awfully small traces going to those terminals?
*Fusible* traces? ;-)
Would not a few real connectors be easier?
My LM135 temp sensors ends in a stereo phono plug, as do all other sensors..
ground, +5 fed via a resistor, and signal.
The same way I drive LEDs.
So I just plug the sensors in like a headphone, and can easily swap each.
The digital inputs / output are driven by a PCF8574 (bidirectional i2c I/O expander),
and the inputs by a PCF8591, a 4 channel i2c 8 bit AD + DA converter.
The i2c hands on 3 pins of the PC par port.
In the original design there was a local LCD driven by 2 PCF8574 remotely too.
No RS232 then.
This has been working since the eighties without problems,
but I accidently killed the LCD (main wire dropped on a data line), and took it out.
The original soft was also in BASIC, MCS BASIC on a 8052 !
Anybody remember MCS BASIC?
Then rewrote it in C, and ported to CP/M.
That C ported to DR DOS.
That DOS C ported to Linux.
And it still works today:-)
Recently I added a temp PIC temp sensor via an USB to RS232 adaptor,
http://panteltje.com/panteltje/pic/temp_pic/index.html
if that sensor fails (is not connected) the software detects it, and switches back to the LM135.
Interesting to write the soft that detects all the possible USB errors, finally
had to have it check the data format the temp_pic sends, to make sure
USB enumeration had not caused some other sensor to be read....
i2c was and is, a lot simpler, not sensitive to random delays due to multi-tasking OS either.
temp_pic sensor is cool, had it in the fridge to -18, and in boiling water to 100 C.
Phil Hobbs
> On Fri, 01 Jan 2010 00:49:11 +0000, Jan Panteltje wrote:
>
>> It is 'bison kit', or translated 'Bison Glue'.
>
Like "What's the difference between a Stoic and a Cynic?
Da stoic is what brings da baby, and da cynic is what you washes it in.
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
55 Orchard Rd
Briarcliff Manor NY 10510
845-480-2058
hobbs at electrooptical dot net
http://electrooptical.net
mook johnson
> circuits using breadboards, power supplies, meters and oscilloscopes.
> Many of today's components don't appear to be breadboard friendly, so how
> is it done today?
>
> Is circuit design software and simulation good enough to go straight to a
> PC board? Or do you use surface mount to breadboard adapters? Do you
> still use a soldering Iron to solder or paste solder and an oven?
>
> solder.
>
> Thanks!
>
>
I use express PCB and get protype boards for less than $100. The time
savings is worth it.
You can also make some miniboards from this stuff.
Joerg
Also, you can bend all the pins up to achieve a living bug. Usually, and
only once. I often take a snippet of thin wood, glue that down, glue the
chip onto that and then solder all the pins that need GND to the copper.
This avoids any pin bending. With wood it's still possible to swap the
chip when you have fried it, not so easy with plastics. Plus gives me a
wonderful excuse to eat a Haagen-Dasz bar with almond crunch on top :-)
> Kapton tape is great, too, when working on copperclad.
>
Yup. The only thing I hate with copper clad is all the ugly fingerprints
after hours of experimenting.
Joerg
It is. However, the $30 for an over-priced board are really down in the
noise for my kind of projects.
> ... I buy it up at flea markets when I
> find good deals and nibble out small pieces for circuits to conserve
> it. I think if I had to pay real prices for vectorboard, I'd use the
> on-line PCB manufacturers. I dead bug too.
>
Wish we had such flea markets up here near Sacramento. But it's mostly a
city of bureaucrats :-(
> Funny nobody mentioned using a board grinder.
Well, if Harborfreight had them for cheap ...
Bill Sloman
wrote:
> On Thu, 31 Dec 2009 09:10:22 -0700, the renowned Don Lancaster
>
>
>
>
>
> <d...@tinaja.com> wrote:
> >John Larkin wrote:
Perhaps. But if the survivors are sufficiently nervous of getting
fired that they triple-check every aspect of the circuit before they
commit to a printed circuit layout, you may find that you get to the
final layout more slowly than you would have if you'd gone through a
throw-away prototype layout along the way.
--
Bill Sloman, Nijmegen
Fred Bartoli
> John Larkin wrote:
>> On Thu, 31 Dec 2009 11:49:37 -0800, Joerg <inv...@invalid.invalid>
>> wrote:
>>
>>> John Larkin wrote:
>>>> On Wed, 30 Dec 2009 20:02:02 -0800, D from BC
>>>> <myreal...@comic.com> wrote:
>>>>
>>>>> On Wed, 30 Dec 2009 20:01:39 -0600, "RogerN" <re...@midwest.net>
>>>>> wrote:
>>>>>
>>>>>> we made circuits using breadboards, power supplies, meters and
>>>>>> oscilloscopes. Many of today's components don't appear to be
>>>>>> breadboard friendly, so how is it done today?
>>>>>>
>>>>>> Is circuit design software and simulation good enough to go
>>>>>> straight to a PC board? Or do you use surface mount to breadboard
>>>>>> adapters? Do you still use a soldering Iron to solder or paste
>>>>>> solder and an oven?
>>>>>>
>>>>>> I'm wanting to tinker with some circuits but some chips I'm
>>>>>> interested in only comes in MSOP or other packages that look
>>>>>> intimidating to attempt to solder.
>>>>>>
>>>>>> Thanks!
>>>>>>
>>>>>> RogerN
>>>>>>
>>>>> If it works on a breadboard, it's not worth producing.
>>>>>
>>>>> On my current project, I have to feed the simulator pcb parasitics and
>>>>> component parasistics to get accurate simulations.
>>>>> I've had to bench test to get some parasitics. Once parasitics are
>>>>> included, scope results and simulation results get close.
>>>>>
>>>>> If all looks good on sim, I make a pcb, etch it and bench test it.
>>>> One problem is that device models often aren't available for fast
>>>> parts, or all you get are S-params when you need large-signal
>>>> time-domain stuff. So sometimes you can learn a lot by hacking some
>>>> FR4 and testing parts.
>>>>
>>>> I never breadboard entire products, or even complex circuits... just
>>>> enough to characterize parts or simple subcircuits.
>>>>
>>>> This is an EL07 driving a PHEMT...
>>>>
>>>> ftp://jjlarkin.lmi.net/BB_fast.JPG
>>>>
>>>> which made decent 5-volt, 1 GHz square waves.
>>>>
>>> How do you get those nice clean cuts into the copper?
>>
>> Just x-acto. The magic trick is to then rub it hard with a Scotchbrite
>> pad. That removes the burrs.
>>
>
> Wow, that is a precise X-acto cut.
>
Xactly
--
Thanks,
Fred.
Joerg
> On Fri, 01 Jan 2010 00:00:40 -0500, Spehro Pefhany wrote:
>
>> On Thu, 31 Dec 2009 09:10:22 -0700, the renowned Don Lancaster
>> <d...@tinaja.com> wrote:
>>
>
>
>>> It is NEVER right the first time.
>> Keep firing people who have that attitude and it eventually will be!
>>
>>
>
>
Old Chinese saying: "Man who says it cannot be done should not interrupt
man doing it" :-)
Spehro Pefhany
<excret...@invalid.invalid> wrote:
>On Fri, 01 Jan 2010 00:00:40 -0500, Spehro Pefhany wrote:
>
>> On Thu, 31 Dec 2009 09:10:22 -0700, the renowned Don Lancaster
>> <d...@tinaja.com> wrote:
>>
>
><snip>
>
>>>
>>>It is NEVER right the first time.
>>
>> Keep firing people who have that attitude and it eventually will be!
>>
>>
>
>Because you'll be doing it all?
No, but, more seriously, there is some correlation between
creativity/intelligence and a kind of disinterest in actually
implementing all of the boring details with precision (and probably
also ability to be managed, but that another story), so you have to be
careful. *Unfounded* optimism is fatal too- one has to be particularly
suspicious of data sheet claims and what evils they may be hiding
behind their happy headlines. And suspicous of boring stuff such as
the accuracy and applicability of stock layout libraries.
If one really cares about getting things right, one can work around
personality by devising checklists and such like that cover off
checking for problems that have occurred in the past-- Kaizen.
And don't hire people who think it takes three board spins to get rid
of most of the fly wires.
John Larkin
wrote:
One of these days I'm going to have a board house gold-plate a bunch
of FR4 scraps. Boy would you guys have breadboard envy!
John
John Larkin
Even better is to have the survivors enjoy their work and their lives,
and do good work because they like to. Getting it right, and
beautiful, becomes a team sport.
There's no limit to how many throw-away prototypes you can do, at
least until the project is cancelled.
John
Phil Hobbs
Your customers already know your stuff is gold-plated. ;)
John Larkin
<pcdhSpamM...@electrooptical.net> wrote:
>On 1/1/2010 10:20 AM, Fred Abse wrote:
>> On Fri, 01 Jan 2010 00:49:11 +0000, Jan Panteltje wrote:
>>
>>> It is 'bison kit', or translated 'Bison Glue'.
>>
>> What is the difference between a buffalo and a bison?
>
>Like "What's the difference between a Stoic and a Cynic?
>
I couldn't care less.
John
Leon
> When I was in school components fit on solderless breadboards and we made
> circuits using breadboards, power supplies, meters and oscilloscopes. Many
> of today's components don't appear to be breadboard friendly, so how is it
> done today?
>
> board? Or do you use surface mount to breadboard adapters? Do you still
> use a soldering Iron to solder or paste solder and an oven?
>
> only comes in MSOP or other packages that look intimidating to attempt to
> solder.
>
>
> RogerN
I generally make a PCB at home, it only takes an hour or so. If a home-
made PCB isn't suitable I use PCBTrain's 24 hour service, it only
costs £30.
Leon
John Devereux
I'm going through this right now. New (208 pin!) microcontroller, ADC,
connectors, SMPS chip. I can spend an extra couple of days re-checking
everything, and I just *know* I will still miss a couple of things. Or I
can just go ahead and make the damn board.
I think I'll just go ahead and see how it turns out. At some point it's
actually quicker and cheaper to debug using the real thing.
--
John Devereux