[sdiy] Breadboards

Charles Bisaillon sdiy at oveloe.com
Tue Jan 3 00:05:13 CET 2006


Ok, so what is your solution then. Your word is greatly appreciated.

Thanks

Charles





> Why I don't use breadboards - by H^) harry
> 
> When I was in college, a good friend of mine designed a circuit.
> It was a theatrical light dimmer. Back in those dark days... many
> theatrical light dimmers were still mechanical, or motor driven
> rheostats
> or variable transformers. There were some commercial thyristor designs,
> but
> they were still in their infancy. (no... they didn't use gaslights back
> then :^)
> 
> The design was a voltage controlled dimmer. 0-10V in for full range
> control.
> 
> He got a commercial prospect to come and see the design. Of course the
> solderless breadboard chose that time to fail. He begged and pleaded...
> just
> five more minutes, it works I swear it does...  Well the guy gave him an
> hour
> to no avail.
> 
> Two hours later, he found a wire that had snuck through a gap in-between
> rows
> and shorted.
> 
> Two hours too late, too bad.  The opportunity was gone.
> 
> LOL... we had a small breadboard at work.  When we were forced to 'clean
> the lab' I helped by offering to throw it away.  It was the ONE thing I
> was sure we would never
> miss :^P
> 
> SMT will certainly obsolete the solderless breadboard. Maybe SMT is not
> ALL bad :^)
> (it will obsolete my favored technique, vectorboard and T42-A pins)
> 
> If you like to use breadboards, that's cool. They were mainly used for
> teaching
> basic electronics in schools, so that parts etc could be re-used. Kind
> of like what they
> do with SPICE today.
> 
> Bob Pease made the following points in his book "Troubleshooting Analog
> Circuits"
> 
> 1) Capacitance: 2-5 pF between adjacent strips "On a good day, only a
> wise engineer
> could plan a layout that all the capacitors, sprinkled throughout the
> circuit, wouldn't ruin"
> 
> 2) Long leads : make adding effective bypass capacitors close to a chip,
> difficult.
> 
> 3) Plastics : esp Nylon, on warm humid days insulation resistance
> suffers (too low).
> 
> 4) Contamination : Solder scrapes off the leads and can build up causing
> shorts.
> The adhesive makes it difficult to blow the scrap away with compressed
> air. (courtesy of Scott Bowman, Dublin CA.)
> 
> Bob concludes...
> 
> "I didn't even think about these solderless breadboards when I wrote my
> series
> because I see them so rarely at work. They just have too many
> disadvantages
> to be good for any serious work. So, if you insist on using these slabs
> of trouble,
> don't say that I didn't warn you."
> 
> The breadboards are like SPICE in many ways. They let you try an idea
> quickly.
> In either case... I would not trust a SPICE simulation until I had built
> the real thing
> and compared the performance (to improve both the circuit, and the spice
> models).
> 
> Be afraid... be very afraid...   :^P
> 
> H^) harry
> 
> 




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