Minimum switch current

[Michael A. Terrell]

I'm sure they thought the same about you.

Next, Bill will deny that the military uses a 24 hour clock for
record keeping, too.

I guess that he never heard of Naval Observatory Time,
http://tycho.usno.navy.mil/


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

 

[Eeyore]

Check with a linguist sometime. Unfortunately, meaning is defined by
wide-spread use. A number of useful words - "gay" is an example - have
been redefined in recent years, despite the fulminations of the usual
pedants.

Your absolute definition of "dry switching" as applying only to a
switch which is totally unloaded doesn't match what I've read in trade
journals and application notes. Idiosyncratic academics do tend to
favour absolute definitions as easier to teach and justify, even if
the concept so defined isn't much use in real life. Who brain-washed
you?

Don't you mean who dropped him on his head as a child ?

Graham

 

[[email protected]]

---
Hmmm...

"The sun shines bright on my old Kentucky home
Tis summer, the darkies are homosexual"? That hardly seems right.
---

Like I said, the word has been redefined since Stephen C. Foster wrote
the lines in 1853.

http://en.wikipedia.org/wiki/My_Old_Kentucky_Home

You think that the term is being used incorrectly. If that is the way
everybody else uses the term today, they are using it correctly. You
might argue that the meaning of the phrase has changed in recent
years, but for that you'd need evidence.

Unlike you, however, once presented with factual evidence (in terms
of the definition given by Leach from the NARM engineers handbook)

A single counter-example? Dating from when?

most of the members of this group seem capable of accepting the
correct definition and moving on with their lives instead of
clinging to preconceptions which they are loath to give up for fear
of having to admit to earlier ignorance.

In the same vein, as far as bowing to group opinion goes, I daresay
that 90% of this group considers the 555 to be an OK chip for some
applications, while you steadfastly reject the majority opinion in
favor of your oft-professed belief that the 555 is a POS.

I'm sure that the 555 is an okay chip for some (very few) applications
- I've not seen one yet but that doesn't mean that such applications
don't exist. It is still a POS.

So it seems your position is that no matter what, anyone who or any
group which disagrees with you is wrong. LOL, so much for being
able to learn, eh?
---

Your position is that you know that the "silent majority" agrees with
you. This is the sort of "knowledge" that is acquired by revelation or
delusion. Either way, you should take whatever it is you use as a
organ of cognition to the nearest psychiatric institution for long
overdue maintenance.

Or so you claim.

If it were true, the extra expense involved in employing true dry
switching would make it impractical, yet we see it done all the time
in applications where contact erosion (metal transfer through a
plasma and the consequent degradation of the contact surface) must
be minimized.
---

Where do you see it done "all the time"? The telephone system never
bothered with what you call true dry switching, and for a very long
time they were the major users of mechanical switches.

---
Don't know what? That banging contacts around mechanically is as
damaging as banging them around mechanically while causing them to
switch current?

That's your daft claim, not mine, which clearly places you in the
ranks of the uninformed minority.
---

For a sufficiently low current, this claim is obviously true. You
might usefully argue about what constitutes a sufficiently low
current, but have instead chosen the daft no-threshold position.

I know you don't understand most of the stuff I post, which leaves you
free to console yourself with idea that it is all bullshit. Dream on.

Not having been obliged to take remedial English, which would have
been the Australian equivalent of English 101, I didn't get the
opportunity to sleep through that particular course. Enclosing your
quote from my post in double quotes did no more than identify it as a
quote. To qualify as an 'idiosyncratic academic' I'd still have to be
both idiosyncratic and an academic, and I'm not an academic. So not
only do you not know what an academic is, but you also have defective
ideas about punctuation. And you haven't yet realised that the 555 is
a POS.

 

[[email protected]]

Next, Bill will deny that the military uses a 24 hour clock for
record keeping, too.

I guess that he never heard of Naval Observatory Time,http://tycho.usno.navy.mil/

Where I come from, we rely on Greenwich Mean Time.

 

[John Fields]

Like I said, the word has been redefined since Stephen C. Foster wrote
the lines in 1853.

---
So, since (according to you) the word has been _lately_ redefined,
we must all now believe that Foster's meaning should be obviated or,
worse yet, taken (according to you) to mean that Blacks in that era
were queer?
---

http://en.wikipedia.org/wiki/My_Old_Kentucky_Home


You think that the term is being used incorrectly. If that is the way
everybody else uses the term today, they are using it correctly. You
might argue that the meaning of the phrase has changed in recent
years, but for that you'd need evidence.


A single counter-example? Dating from when?


I'm sure that the 555 is an okay chip for some (very few) applications
- I've not seen one yet but that doesn't mean that such applications
don't exist. It is still a POS.


Your position is that you know that the "silent majority" agrees with
you. This is the sort of "knowledge" that is acquired by revelation or
delusion. Either way, you should take whatever it is you use as a
organ of cognition to the nearest psychiatric institution for long
overdue maintenance.


Or so you claim.


Where do you see it done "all the time"? The telephone system never
bothered with what you call true dry switching, and for a very long
time they were the major users of mechanical switches.


For a sufficiently low current, this claim is obviously true. You
might usefully argue about what constitutes a sufficiently low
current, but have instead chosen the daft no-threshold position.


I know you don't understand most of the stuff I post, which leaves you
free to console yourself with idea that it is all bullshit. Dream on.


Not having been obliged to take remedial English, which would have
been the Australian equivalent of English 101, I didn't get the
opportunity to sleep through that particular course. Enclosing your
quote from my post in double quotes did no more than identify it as a
quote. To qualify as an 'idiosyncratic academic' I'd still have to be
both idiosyncratic and an academic, and I'm not an academic. So not
only do you not know what an academic is, but you also have defective
ideas about punctuation. And you haven't yet realised that the 555 is
a POS.

---
Well, Bill, I see that, as usual, your "genius" manages to cast you
in the light which suits you best, if you know what I mean, wink,
wink, nudge, nudge, so I'll take this opportunity to disengage.

Goodbye, and have a pleasant day if you can.

 

[John Fields]

Where I come from, we rely on Greenwich Mean Time.

 

[Michael A. Terrell]

??? They have their own atomic clocks:
http://tycho.usno.navy.mil/master.html USNO was started in 1845, long
before NBS/NIST got into master time activities.


NIST is a 24 hour clock system, not AM/PM.
http://tf.nist.gov/stations/wwvbtimecode.htm The first US radio
transmission of time signals was by the US NAVY.

http://tf.nist.gov/stations/wwvb.htm
http://tf.nist.gov/stations/wwvbhistory.htm
http://tf.nist.gov/stations/morevbpics.html


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

 

[[email protected]]

The various national standards laboratories do collaborate in cross-
checking the various national standards.

The first cesium-based atomic clock was developed at the UK national
standards lab in 1955

http://physics.nist.gov/GenInt/Time/biblio.html

 

[[email protected]]

---
So, since (according to you) the word has been _lately_ redefined,
we must all now believe that Foster's meaning should be obviated or,
worse yet, taken (according to you) to mean that Blacks in that era
were queer?

People who don't understand that words can change in meaning over time
can misunderstand historical documents. Your National Rifle
Association and your Supreme Court do seem to have misinterpreted the
second amendment to the consitution in this way.

http://en.wikipedia.org/wiki/Second_Amendment_to_the_United_States_Constitution

---
Well, Bill, I see that, as usual, your "genius" manages to cast you
in the light which suits you best, if you know what I mean, wink,
wink, nudge, nudge, so I'll take this opportunity to disengage.

Goodbye, and have a pleasant day if you can.

Scarcely a graceful concession, but a concession, none the less.

 

[John McMillan]

The various national standards laboratories do collaborate in cross-
checking the various national standards.

The first cesium-based atomic clock was developed at the UK national
standards lab in 1955

http://physics.nist.gov/GenInt/Time/biblio.html

isn't international time keeping currently the responsibility
of the delightfully named International Earth Rotation Service in Paris?

http://hpiers.obspm.fr/

 

[Michael A. Terrell]

isn't international time keeping currently the responsibility
of the delightfully named International Earth Rotation Service in Paris?

http://hpiers.obspm.fr/

Maybe in your neck of the woods.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

 

[John Fields]

The various national standards laboratories do collaborate in cross-
checking the various national standards.

The first cesium-based atomic clock was developed at the UK national
standards lab in 1955

http://physics.nist.gov/GenInt/Time/biblio.html

 

[[email protected]]

---
That was over 50 years ago.

Are you claiming that the USNIST isn't the primary timekeeper for
the world today?

I imagine that it is one of the primary timekeepers. What is your
evidence to indicate that it is *the* primary timekeeper?

 

[John Fields]

People who don't understand that words can change in meaning over time
can misunderstand historical documents. Your National Rifle
Association and your Supreme Court do seem to have misinterpreted the
second amendment to the consitution in this way.

http://en.wikipedia.org/wiki/Second_Amendment_to_the_United_States_Constitution



Scarcely a graceful concession, but a concession, none the less.

 

[[email protected]]

Dream on.

 

[John Fields]

Dream on.

---
LOL, _you're_ the one who seems to be in the land of Nod, what with
your grasping at straws trying to make your dream come out the way
you want it to instead of the nightmare it's become.

Fact: No matter how much you wriggle and squirm, in the end dry
switching refers to contacts which don't hot switch, and:

Fact: The 555 is a neat little chip. If you'd have come up with it
you'd have no trouble extolling its virtues, ad nauseam but, since
you didn't, you damn it.

Sour grapes, loser.

 

[John Fields]

---
LOL, _you're_ the one who seems to be in the land of Nod, what with
your grasping at straws trying to make your dream come out the way
you want it to instead of accepting the nightmare it's become. ^^^^^^^^^
added

Fact: No matter how much you wriggle and squirm, in the end dry
switching refers to contacts which don't hot switch, and:

Fact: The 555 is a neat little chip. If you'd have come up with it
you'd have no trouble extolling its virtues, ad nauseam but, since
you didn't, you damn it.

Sour grapes, loser.

 

[[email protected]]

---
LOL, _you're_ the one who seems to be in the land of Nod, what with
your grasping at straws trying to make your dream come out the way
you want it to instead of the nightmare it's become.

Fact: No matter how much you wriggle and squirm, in the end dry
switching refers to contacts which don't hot switch, and:

Dream on.

Fact: The 555 is a neat little chip. If you'd have come up with it
you'd have no trouble extolling its virtues, ad nauseam but, since
you didn't, you damn it.

The 555 is a neat little chip. Back when Hans Camenzind came up with
it, it was a handy little chip, but it has long since had its day -
people who know about the stuff that has been developed since then use
other, neater, devices that aren't quite as rudimentary.

Sour grapes, loser.

So you like to think, fossil.

 

[Paul Hovnanian P.E.]

I noticed that some switches are specified for a minimum current as well as a
maximum current. Someone once told me that this is because that minimum current
is needed to "burn away" oxides where the metals contact. Well, this is a
problem for me because I am designing a low-power device that will run on a coin
cell battery. The switch that I want to use is specified for 1 ma. minimum
current. But I want to use the internal microcontroller pull-up for this user
input switch. Are there some types of switches that have no minimum current?
How much trouble can I expect if I just ignore the spec? What about putting a
01 uF cap around the switch to produce a short burst of high current when the
switch is closed?

Robert Scott
Ypsilanti, Michigan

How much time will this switch spend closed? If its closed for a short
time (as in a momentary pushbutton for a TV remote control), add a
resistor to draw some more current. Heck, that's what those 'kewl blue'
LEDs are for. ;-)