How do you design these days?
in [Design]
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From: Phil Hobbs on 1 Jan 2010 12:54 On 1/1/2010 12:50 PM, John Larkin wrote: > On Fri, 01 Jan 2010 08:49:20 -0800, Joerg<invalid(a)invalid.invalid> > wrote: > >> John Larkin wrote: >>> On Thu, 31 Dec 2009 19:28:42 -0800 (PST), "miso(a)sushi.com" >>> <miso(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. >>> >> >> 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. > > 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 > Your customers already know your stuff is gold-plated. ;) 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
From: John Larkin on 1 Jan 2010 13:10 On Fri, 01 Jan 2010 11:28:56 -0500, Phil Hobbs <pcdhSpamMeSenseless(a)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
From: Leon on 1 Jan 2010 13:26 On 31 Dec 2009, 02:01, "RogerN" <re...(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! > > 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
From: John Devereux on 1 Jan 2010 13:33 Bill Sloman <bill.sloman(a)ieee.org> writes: > On Jan 1, 6:00 am, Spehro Pefhany <speffS...(a)interlogDOTyou.knowwhat> > wrote: >> On Thu, 31 Dec 2009 09:10:22 -0700, the renowned Don Lancaster >> >> >> >> >> >> <d...(a)tinaja.com> wrote: >> >John Larkin wrote: >> >> On Thu, 31 Dec 2009 14:01:44 -0000, "markp" <map.nos...(a)f2s.com> >> >> wrote: >> >> >>> "RogerN" <re...(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! > > 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. 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
From: Phil Hobbs on 1 Jan 2010 13:40
On 1/1/2010 1:10 PM, John Larkin wrote: > On Fri, 01 Jan 2010 11:28:56 -0500, Phil Hobbs > <pcdhSpamMeSenseless(a)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 > Snow a bit heavy, is it? ;) 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 |