How do you design these days?
in [Design]
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From: Spehro Pefhany on 1 Jan 2010 00:00 On Thu, 31 Dec 2009 09:10:22 -0700, the renowned Don Lancaster <don(a)tinaja.com> wrote: >John Larkin wrote: >> On Thu, 31 Dec 2009 14:01:44 -0000, "markp" <map.nospam(a)f2s.com> >> wrote: >> >>> "RogerN" <regor(a)midwest.net> wrote in message >>> news:ROudnXLvg9-Tm6HWnZ2dnUVZ_oidnZ2d(a)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" speff(a)interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com
From: miso on 1 Jan 2010 01:55 On Dec 31, 7:43 pm, John Larkin <jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: > On Thu, 31 Dec 2009 19:28:42 -0800 (PST), "m...(a)sushi.com" > > > > <m...(a)sushi.com> wrote: > >On Dec 31, 12:50 pm, Joerg <inva...(a)invalid.invalid> wrote: > >> 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? > > >> >> 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. > > >> -- > >> 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. > > 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 The backwards pinout is an issue. I sharpie the pin numbers after I mount the dead bug.
From: David L. Jones on 1 Jan 2010 03:46 Jon Kirwan wrote: > On Wed, 30 Dec 2009 20:01:39 -0600, "RogerN" <regor(a)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! > > 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
From: Jan Panteltje on 1 Jan 2010 08:42 On a sunny day (Thu, 31 Dec 2009 17:22:14 -0800) it happened Joerg <invalid(a)invalid.invalid> wrote in <7q512eFt0gU1(a)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.
From: Jan Panteltje on 1 Jan 2010 09:06
On a sunny day (Thu, 31 Dec 2009 18:13:00 -0800) it happened John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote in <q9mqj5dsgr3mvime8j2brar18l538grq67(a)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. |