some breadboards
in [Design]
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From: John Larkin on 8 Apr 2010 22:24 On Thu, 08 Apr 2010 20:09:20 -0500, "krw(a)att.bizzzzzzzzzzzz" <krw(a)att.bizzzzzzzzzzzz> wrote: >On Thu, 08 Apr 2010 17:57:40 -0700, John Larkin ><jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: > >>On Thu, 08 Apr 2010 19:46:29 -0500, "krw(a)att.bizzzzzzzzzzzz" >><krw(a)att.bizzzzzzzzzzzz> wrote: >> >>>On Thu, 8 Apr 2010 17:12:33 -0700 (PDT), brent <bulegoge(a)columbus.rr.com> >>>wrote: >>> >>>>On Apr 8, 8:10�pm, John Larkin >>>><jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: >>>>> ftp://jjlarkin.lmi.net/BreadBoards.jpg >>>>> >>>>> ftp://jjlarkin.lmi.net/BreadBoards2.JPG >>>>> >>>>> John >>>> >>>>Are these your first pass board designs that you plan to put into >>>>production? >>> >>>Nice! ;-) >> >>If I test the parts I don't fully understand, the products will work >>first pass. *That* is nice. > >>A breadboard is not a prototype. It's a way to better understand a >>part. The "circuit" of such a breadboard is unlikely to appear in any >>deliverable product. > >Just bustin' your chops, John. I'm on your side in that kerfuffle (though >don't often come up to your standards), but funny is funny. And besides, I need to solder and play with parts now and then. If I ever quit soldering, just have me recycled. John
From: TerryKing on 9 Apr 2010 04:32 > And besides, I need to solder and play with parts now and then. If I > ever quit soldering, just have me recycled.> John John, I also like the "Reality Approach"! And sometimes the 'input signal' to a device isn't what you really thought it was. Even if (especially if?) it is coming from another of my designs :-) Then what the device DOES with that signal and therefore what the output signal really is, can be a nasty surprise. As my favorite tech at IBM used to say, "If what the scope shows us is Wrong or Impossible that is it's way of telling us that there are things we don't understand!" (Later they made him a Manager. What a waste! ) Regards, Terry King ..On the Red Sea at KAUST terry(a)terryking.us
From: Frnak McKenney on 9 Apr 2010 09:38 On Thu, 08 Apr 2010 17:45:20 -0700, John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: > On Thu, 8 Apr 2010 17:12:33 -0700 (PDT), brent ><bulegoge(a)columbus.rr.com> wrote: > >>On Apr 8, 8:10�pm, John Larkin >><jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: >>> ftp://jjlarkin.lmi.net/BreadBoards.jpg >>> >>> ftp://jjlarkin.lmi.net/BreadBoards2.JPG [...] > I especially like to test parts to destruction, to see what sorts of > margins I'm going to have in real life. Earlier this week I blew up a > bunch of 1206 resistors and SSRs to see how a product might behave if > arbitrarily over-voltaged, to estimate which parts would fail, and > when, so I could put some limits on a datasheet. I now have, > essentially, SOAR curves for these parts. Some guys have all the fun! <grin> Frank McKenney -- The preservation of truth values when translating scientific prose is very nearly as delicate a task as the preservation of resonance and emotional tone in the translation of literature. Neither can be fully achieved; even responsible approximation requires the greatest tact and taste. -- Thomas S. Kuhn / The Road Since 'Structure' -- Frank McKenney, McKenney Associates Richmond, Virginia / (804) 320-4887 Munged E-mail: frank uscore mckenney ayut mined spring dawt cahm (y'all)
From: MooseFET on 9 Apr 2010 10:15 On Apr 8, 6:16 pm, John Larkin <jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: > On Thu, 8 Apr 2010 18:01:57 -0700 (PDT), brent > > > > <buleg...(a)columbus.rr.com> wrote: > >On Apr 8, 8:57 pm, John Larkin > ><jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: > >> On Thu, 08 Apr 2010 19:46:29 -0500, "k...(a)att.bizzzzzzzzzzzz" > > >> <k...(a)att.bizzzzzzzzzzzz> wrote: > >> >On Thu, 8 Apr 2010 17:12:33 -0700 (PDT), brent <buleg...(a)columbus.rr.com> > >> >wrote: > > >> >>On Apr 8, 8:10 pm, John Larkin > >> >><jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: > >> >>>ftp://jjlarkin.lmi.net/BreadBoards.jpg > > >> >>>ftp://jjlarkin.lmi.net/BreadBoards2.JPG > > >> >>> John > > >> >>Are these your first pass board designs that you plan to put into > >> >>production? > > >> >Nice! ;-) > > >> If I test the parts I don't fully understand, the products will work > >> first pass. *That* is nice. > > >> A breadboard is not a prototype. It's a way to better understand a > >> part. The "circuit" of such a breadboard is unlikely to appear in any > >> deliverable product. > > >> John > > >First pass design means first pass design. This should all be modeled > >and you should not be wasting someones time to build these boards when > >a handy dandy simulator program is available. > > You can't usefully simulate a system without good part models, and > lots of parts have no or bad models. Especially RF parts used in > nonlinear or time-domain apps. Models are also bad in the following cases: Basically no op-amp model correctly shows the power supply current. Op-amps that are crashed into the rails or slew rate limited don't recover like the model suggests. Linears switcher chips are about the only ones that have anything like models that work. The recovery of the body diode in power MOSFETs is almost never fully specified in datasheets. Many have a long tail of noisy current. The noise performance of DACs are seldom fully characterized. Gate leakage in JFETs is usually not modeled.
From: Nico Coesel on 9 Apr 2010 13:45
John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >On Thu, 08 Apr 2010 19:46:29 -0500, "krw(a)att.bizzzzzzzzzzzz" ><krw(a)att.bizzzzzzzzzzzz> wrote: > >>On Thu, 8 Apr 2010 17:12:33 -0700 (PDT), brent <bulegoge(a)columbus.rr.com> >>wrote: >> >>>On Apr 8, 8:10�pm, John Larkin >>><jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: >>>> ftp://jjlarkin.lmi.net/BreadBoards.jpg >>>> >>>> ftp://jjlarkin.lmi.net/BreadBoards2.JPG >>>> >>>> John >>> >>>Are these your first pass board designs that you plan to put into >>>production? >> >>Nice! ;-) > >If I test the parts I don't fully understand, the products will work >first pass. *That* is nice. > >A breadboard is not a prototype. It's a way to better understand a >part. The "circuit" of such a breadboard is unlikely to appear in any >deliverable product. Those parts seem relatively easy. In some cases I have a PCB made to test a particular piece of circuitry. That often leads to interesting discoveries! -- Failure does not prove something is impossible, failure simply indicates you are not using the right tools... nico(a)nctdevpuntnl (punt=.) -------------------------------------------------------------- |