Searcher7 wrote:

Tim Wescott wrote:

There are no "normal" environmental conditions -- only the environmental
conditions that people of limited imagination assume is normal.

So that you will understand what I meant, the switches will not have
to operate in space, under the ocean's surface, immersed in harsh
chemicals or substances, or temperatures below or above what humans
consider comfortable.


Will it be in a vacuum? If not, you have a lot of arcing & surface
oxidation that will degrade the contacts. Real switches use some type
of contact lube to keep oxygen away from the contacts. Also, you never
want any silicon based lube on switch contacts. The phone companies
learned that the hard way.


Yes, I think we all understand that. What we didn't know until this
moment, though, is that you had considered silver plating and decided
against it for cost reasons.

Because, you see, we can't read your mind.

You still don't know that. Because it's not true. I decided against
*any* plating of whatever materials I settled on for reasons involving
complexity. Even cost was secondary. But way address it if it had
nothing to do with my original question?


If you can't replicate _just the forces and actions_ of an existing
switch at the contacts, then you're in a different universe from me, and
no advise that I can give you will help. In fact, no amount of advise
that you get from any of the regulars here will help, because as far as I
know they're all in the same universe as I am, too.

I'm not sure what you meant by "replicate _just the forces and
actions_ of an existing switch at the contacts". Or if you were
referring to general principles or copying exactly. But either way
this has all been addressed in my design and has nothing to do with
the wiping material question.

I set the parameters for the shape, number, and arrangement of
Phosphor-Bronze contacts, as well as the allotted space needed and
supplied by the encasement because it had to be done in order for the
switch to accomplish was is needed.

Perhaps this is why you thought that the help you got on s.e.b was all
from trolls? Getting sound engineering advice from the wrong universe
can do that.

I don't know what this universe stuff is about, but personal attacks
are of a different order. I couldn't tell if there was a genuine
failure to understand my simple question or just immaturity at work.


It means that you have to obey the same laws of physics as everyone
else.


I asked if Phosphor-Bronze was an acceptable wiping material for
Phosphor-Bronze because I wasn't sure if there would be any problems
with using a different metal as the wiping material even though
contact during wiping is brief.


Wiping requires force. It sounds like it won't do you any good.


Here in this universe, how you _connect_ to a switch is largely
independent of how the _switch's contacts come together_, and with what
forces. This applies in particular if your switch is currently just a
connection diagram, and has not been reduced to practice in a way that
involves any means of making the contacts come together, with or without
any forces.

I'm not sure what that meant, or what exactly you are addressing. But
since this is my design, as I mentioned I have control and the option
to change all important variables like "contact thickness, number of
wipes between connections, length of wipes between connections,
pressure of wipes between connections..."


Remember mechanical TV tuners? The cheap ones depended only on
'wiping action' and very thin plating. As soon as the plating wore
through they were unrepairable. Contact resistance is important to
proper switch design, in all cases.


John Fields is pretty astute, and engineers learn early not to answer
general questions with specifics. "How much paint does it take to paint
a door?" should be immediately replied to with "How big is the door, and
what sort of paint?", because any specific answer is only going to be
correct if the questioner and respondent both share all the same
assumptions.

I have no idea how "astute" John is. I only know that like several
others on that group, his maturity level needs work.


You should talk. John has designed and built custom electronics for
decades. OTOH, he doesn't like to waste time on people who ask
questions and ignore the answers.


And if I asked if it was reasonable to make a door knob out of metal,
then I shouldn't expect to be berated because I didn't include
information on the size of the door or what kind of paint I'd be using
on it.


If you asked that on an electronics group you would deserve to be
treated like a troll. You asked a question and gave no information.
Engineers want to know what you really need, not what you think you
want. Your doorknob statement proves that. Even doorknobs aren't 'one
size fits all'.