resistance of brass strip

P

Parl

Guest
I want to make a battery tester. I am in the UK.

I'll use a fixed metal sheet which I will press the positive stud of a
cell on. (A meter probe will go to the other end.)



(1) I tried an aluminium sheet for the metal but it didn't make good
contact possibly on account of repeated re-tarnishing.


(2) I'm considering a metal strip like the contacts on a 1289 (3LR12)
battery: http://www.smallbattery.company.org.uk/sbc_3LR12.jpg

However I think the strips are and when I look at the electrical
conductivity of brass it seems quite poor compared to copper. If brass
is really a poor conductor then why is it used on a battery?

(3) What alternative material could I use? Perhaps a plated metal
sheet of some sort?
 
Parl wrote:

I want to make a battery tester. I am in the UK.

I'll use a fixed metal sheet which I will press the positive stud of a
cell on. (A meter probe will go to the other end.)



(1) I tried an aluminium sheet for the metal but it didn't make good
contact possibly on account of repeated re-tarnishing.


(2) I'm considering a metal strip like the contacts on a 1289 (3LR12)
battery: http://www.smallbattery.company.org.uk/sbc_3LR12.jpg

However I think the strips are and when I look at the electrical
conductivity of brass it seems quite poor compared to copper. If brass
is really a poor conductor then why is it used on a battery?
Proably mechanical properties - it is nicer to machine than copper

(3) What alternative material could I use? Perhaps a plated metal
sheet of some sort?
Brass would be OK until it tarnishes, at which point you would need to clean
it with sandpaper. Brass is a very poor conductor compared to copper, but
for a few amps it is OK, e.g. the pins of 13 Amp plugs are brass.
Nickel-plated brass or copper, or bare stainless steel (which is
impractical to soft-solder under normal circumstances) may be more
resistant to corrosion and tarnishing, or gold would be ideal - either as a
plating or solid depending on budget.

Chris
 
In article <Xns9BBCE36A437BF74C1H4@194.177.98.144>,
Parl <mail@nomail.invalid> wrote:

However I think the strips are and when I look at the electrical
conductivity of brass it seems quite poor compared to copper. If brass
is really a poor conductor then why is it used on a battery?
Alloys are going to have lower conductivity than pure metals. Electrons
scatter from defects (crystal disorder). But usually alloys are good
enough. Even a thick nichrome is likely to be good enough for your
purpose. Tin/lead solder is a poor conductor, but because it melts at a
low temperature, it is used to provide good connections in electronic
equipment,

Bill

--
Private Profit; Public Poop! Avoid collateral windfall!
 
On Thu, 26 Feb 2009 18:47:06 -0800 (PST), Engineer <junk2007@rogers.com>
wrote:

On Feb 24, 5:21 pm, Parl <m...@nomail.invalid> wrote:
I want to make a battery tester.  I am in the UK.

I'll use a fixed metal sheet which I will press the positive stud of a
cell on.  (A meter probe will go to the other end.)

(1) I tried an aluminium sheet for the metal but it didn't make good
contact possibly on account of repeated re-tarnishing.

(2) I'm considering a metal strip like the contacts on a 1289 (3LR12)
battery:http://www.smallbattery.company.org.uk/sbc_3LR12.jpg

However I think the strips are and when I look at the electrical
conductivity of brass it seems quite poor compared to copper. If brass
is really a poor conductor then why is it used on a battery?

(3) What alternative material could I use? Perhaps a plated metal
sheet of some sort?

Use might try brass with a blob (pad) of soft solder where you want to
touch the battery - it will be soft enough to break any tarnish each
time you use it. In your application the higher resistance of the
brass compared to copper will be completely negligable.
Cheers,
Roger
Tin plated copper strip is also available out there in various gauges.

Tinning the attachment hole will kill any tarnish problems.

Silver Plated Copper wire works real good as a conductor too. ;-)
 
On Feb 24, 5:21 pm, Parl <m...@nomail.invalid> wrote:
I want to make a battery tester.  I am in the UK.

I'll use a fixed metal sheet which I will press the positive stud of a
cell on.  (A meter probe will go to the other end.)

(1) I tried an aluminium sheet for the metal but it didn't make good
contact possibly on account of repeated re-tarnishing.

(2) I'm considering a metal strip like the contacts on a 1289 (3LR12)
battery:http://www.smallbattery.company.org.uk/sbc_3LR12.jpg

However I think the strips are and when I look at the electrical
conductivity of brass it seems quite poor compared to copper. If brass
is really a poor conductor then why is it used on a battery?

(3) What alternative material could I use? Perhaps a plated metal
sheet of some sort?
Use might try brass with a blob (pad) of soft solder where you want to
touch the battery - it will be soft enough to break any tarnish each
time you use it. In your application the higher resistance of the
brass compared to copper will be completely negligable.
Cheers,
Roger
 
Parl wrote:
I want to make a battery tester. I am in the UK.

I'll use a fixed metal sheet which I will press the positive stud of a
cell on. (A meter probe will go to the other end.)



(1) I tried an aluminium sheet for the metal but it didn't make good
contact possibly on account of repeated re-tarnishing.


(2) I'm considering a metal strip like the contacts on a 1289 (3LR12)
battery: http://www.smallbattery.company.org.uk/sbc_3LR12.jpg

However I think the strips are and when I look at the electrical
conductivity of brass it seems quite poor compared to copper. If brass
is really a poor conductor then why is it used on a battery?

(3) What alternative material could I use? Perhaps a plated metal
sheet of some sort?
Put a blob of high silver content silver solder on your brass or copper
 
Parl wrote:
I want to make a battery tester. I am in the UK.

I'll use a fixed metal sheet which I will press the positive stud of a
cell on. (A meter probe will go to the other end.)



(1) I tried an aluminium sheet for the metal but it didn't make good
contact possibly on account of repeated re-tarnishing.


(2) I'm considering a metal strip like the contacts on a 1289 (3LR12)
battery: http://www.smallbattery.company.org.uk/sbc_3LR12.jpg

However I think the strips are and when I look at the electrical
conductivity of brass it seems quite poor compared to copper. If brass
is really a poor conductor then why is it used on a battery?

(3) What alternative material could I use? Perhaps a plated metal
sheet of some sort?

The amount of brass involved isn't going to make much difference from
copper contacts. It is a very small part of the total circuit
resistance. The advantage of brass is that it is harder and wont deform
when you slot a battery between the contacts. In addition, it is going
to allow a higher contact pressure and wiping of the surface each time
you put the battery in place. This wiping is the important factor as it
cleans the contact surface.

Where a brass contact is iffy is in the mv or lower range. As an
example, consider a modern AC 120V 15A switch (which is rather poor in
wiping compared to a DC rated switch). In an application for a gas
fireplace using a millivolt source, it works well- for a while - then
contact problems occur (this doesn't happen with a 12V automotive
switch) which has good wiping action) - and, my personal experience is
that a nickel plated 120V AC switch (a bit more expensive and also
non-wiping) works well for a much longer time- how long- I don't know as
after about 10 years, there have been no problems where 6 months with a
brass non wiping contact gave problems.
Note: nickel has roughly twice the resistivity of brass so the advantage
is due to less of a surface film.
So you don't want to simply press the battery contact to the brass plate
but put it on with a rubbing action as in most chargers or battery holders.

Don Kelly
dhky@shawcross.ca
remove X to reply
 
On Feb 28, 12:12 am, Don Kelly <d...@shawcross.ca> wrote:
Parl wrote:
I want to make a battery tester.  I am in the UK.

I'll use a fixed metal sheet which I will press the positive stud of a
cell on.  (A meter probe will go to the other end.)

(1) I tried an aluminium sheet for the metal but it didn't make good
contact possibly on account of repeated re-tarnishing.

(2) I'm considering a metal strip like the contacts on a 1289 (3LR12)
battery:http://www.smallbattery.company.org.uk/sbc_3LR12.jpg

However I think the strips are and when I look at the electrical
conductivity of brass it seems quite poor compared to copper. If brass
is really a poor conductor then why is it used on a battery?

(3) What alternative material could I use? Perhaps a plated metal
sheet of some sort?

The amount of brass involved isn't going to make much difference from
copper contacts. It is a very small part of the total circuit
resistance. The advantage of brass is that it is harder and wont deform
when you slot a battery between the contacts. In addition, it is going
to allow a higher contact pressure and wiping of the surface each time
you put the battery in place. This wiping is the important factor as it
cleans the contact surface.

Where a brass contact is iffy is in the mv or lower range. As an
example, consider a modern AC 120V 15A switch (which is rather poor in
wiping compared to a DC rated switch). In an application for a gas
fireplace using a millivolt source, it works well- for a while - then
contact problems occur (this doesn't happen with a 12V automotive
switch) which has good wiping action) - and, my personal experience is
that a nickel plated 120V AC switch (a bit more expensive and also
non-wiping) works well for a much longer time- how long- I don't know as
after about 10 years, there have been no problems where 6 months with a
brass non wiping contact gave problems.
Note: nickel has roughly twice the resistivity of brass so the advantage
is due to less of a surface film.
So you don't want to simply press the battery contact to the brass plate
but put it on with a rubbing action as in most chargers or battery holders.

Don Kelly
d...@shawcross.ca
remove X to reply- Hide quoted text -

- Show quoted text -
HMPH! SOUNDS ALL TOO DUBIOUS

I AM PROTEUS
 
On Wed, 4 Mar 2009 05:20:47 -0800 (PST), proteusiiv@gmail.com wrote:

HMPH! SOUNDS ALL TOO DUBIOUS

I AM PROTEUS

What an idiot like you knows about metallurgy would fit on the tip of a
molecular probe.
 
Archimedes' Lever wrote:
On Wed, 4 Mar 2009 05:20:47 -0800 (PST), proteusiiv@gmail.com wrote:

HMPH! SOUNDS ALL TOO DUBIOUS

I AM PROTEUS


What an idiot like you knows about metallurgy would fit on the tip of a
molecular probe.
You mean, as a troll you know about anything????
 
On Mar 4, 8:17 pm, Archimedes' Lever <OneBigLe...@InfiniteSeries.Org>
wrote:
On Wed, 4 Mar 2009 05:20:47 -0800 (PST), proteus...@gmail.com wrote:

HMPH!  SOUNDS ALL TOO DUBIOUS

I AM PROTEUS

 What an idiot like you knows about metallurgy would fit on the tip of a
molecular probe.
FAGGOT CLEAN MY PROBE

I HAVE DESIGNED MICRO PARTS ALRIGHT
THERE IS A NANO SIZED VERSION OF YOUR BRAIN
NO WAIT THAT IS YOUR BRAIN

I AM PROTEUS
 
On Mar 4, 8:17 pm, Archimedes' Lever <OneBigLe...@InfiniteSeries.Org>
wrote:
On Wed, 4 Mar 2009 05:20:47 -0800 (PST), proteus...@gmail.com wrote:

HMPH!  SOUNDS ALL TOO DUBIOUS

I AM PROTEUS

 What an idiot like you knows about metallurgy would fit on the tip of a
molecular probe.

BY YOUR TRACK RECORD WITH OTHERS HERE I HAVE DETERMINDED THAT THAT IS
ABOUT THE SIZE OF YOUR HEART TOO

I AM PROTEUS
 
On Mon, 9 Mar 2009 06:21:18 -0700 (PDT), proteusiiv@gmail.com wrote:

I HAVE DESIGNED MICRO PARTS ALRIGHT

Sure you have.
 
On Mar 9, 7:16 pm, Archimedes' Lever <OneBigLe...@InfiniteSeries.Org>
wrote:
On Mon, 9 Mar 2009 06:21:18 -0700 (PDT), proteus...@gmail.com wrote:

I HAVE DESIGNED MICRO PARTS ALRIGHT

  Sure you have.
OF COURSE I HAVE YOU FAGGOTY CALIFORNIAN FORNICATOR
I HAVE A GREAT TEAM AND HAVE SPECIFIED METALALURGY FOR PARTS FOR THEM
AS WELL

YOU THOUGHT YOU KNEW EVERYTHING & EVERYONE IN THE GROUP
YOU ERRED YOU ARE WROYNG
YOU HAVE CAUSE LOTS OF DAMAGE
YOU ARE A GREATER PROBLEM THAN YOU THINK AND HAVE BEEN FOUND NOT WORTH
THE EFFORTS

YOU MUST MAKE AMENDS OR YOU WILL NEVER REACH A COLLECTIVE GOAL AGAIN

I AM PROTEUS
 
I HAVE ALSO SPECIFIED THE ELEMENTS AND THEIR PHYSICAL CHARACTERISTICS
INTO DESIGN PARAMETERS WITH FUNCTIONAL EXPANSIONS AND EXPECTATIONS

THIS BRASS STRIP CONUNDRUM IS PETTY TO ME AND HAS LONG RESOLVED

I AM PROTEUS
 
On Tue, 10 Mar 2009 05:41:07 -0700 (PDT), proteusiiv@gmail.com wrote:

On Mar 9, 7:16 pm, Archimedes' Lever <OneBigLe...@InfiniteSeries.Org
wrote:
On Mon, 9 Mar 2009 06:21:18 -0700 (PDT), proteus...@gmail.com wrote:

I HAVE DESIGNED MICRO PARTS ALRIGHT

  Sure you have.

OF COURSE I HAVE YOU FAGGOTY CALIFORNIAN FORNICATOR
I HAVE A GREAT TEAM AND HAVE SPECIFIED METALALURGY FOR PARTS FOR THEM
AS WELL
That might even be believable if you could actually spell the word
metallurgy.
YOU THOUGHT YOU KNEW EVERYTHING & EVERYONE IN THE GROUP
Nope. Never made any such statement. I do know an idiot when one
posts, however, idiot.

YOU ERRED YOU ARE WROYNG
YOU HAVE CAUSE LOTS OF DAMAGE
YOU ARE A GREATER PROBLEM THAN YOU THINK AND HAVE BEEN FOUND NOT WORTH
THE EFFORTS
Giving up so soon? What a pussy.

YOU MUST MAKE AMENDS OR YOU WILL NEVER REACH A COLLECTIVE GOAL AGAIN
I do fine every day. The company I work for will NEVER have hard
economic times.

The building owner you work for might want a cheaper Bldg Supr, however.
You fail in two areas. Brains, and ambition.

I AM PROTEUS
No, you are Roy, an utter idiot, that hasn't stopped crying since the
group saw you for what you are.
 
On Mar 10, 8:03 pm, Archimedes' Lever <OneBigLe...@InfiniteSeries.Org>
wrote:
On Tue, 10 Mar 2009 05:41:07 -0700 (PDT), proteus...@gmail.com wrote:
On Mar 9, 7:16 pm, Archimedes' Lever <OneBigLe...@InfiniteSeries.Org
wrote:
On Mon, 9 Mar 2009 06:21:18 -0700 (PDT), proteus...@gmail.com wrote:

I HAVE DESIGNED MICRO PARTS ALRIGHT

  Sure you have.

OF COURSE I HAVE YOU FAGGOTY CALIFORNIAN FORNICATOR
I HAVE A GREAT TEAM AND HAVE SPECIFIED METALALURGY FOR PARTS FOR THEM
AS WELL

 That might even be believable if you could actually spell the word
metallurgy.



YOU THOUGHT YOU KNEW EVERYTHING & EVERYONE IN THE GROUP

 Nope.  Never made any such statement.  I do know an idiot when one
posts, however, idiot.

YOU ERRED YOU  ARE WROYNG
YOU HAVE CAUSE LOTS OF DAMAGE
YOU ARE A GREATER PROBLEM THAN YOU THINK AND HAVE BEEN FOUND NOT WORTH
THE EFFORTS

  Giving up so soon?  What a pussy.

YOU MUST MAKE AMENDS OR YOU WILL NEVER REACH A COLLECTIVE GOAL AGAIN

 I do fine every day.  The company I work for will NEVER have hard
economic times.

 The building owner you work for might want a cheaper Bldg Supr, however.
You fail in two areas.  Brains, and ambition.

I AM PROTEUS

  No, you are Roy, an utter idiot,<=THIS IS WHAT GOT YOU PEGGED THE FAGGOT OF THE GRPOUP] that hasn't stopped crying since the
group saw you for what you are.
WHATEVER OR WHOM EVER YOU FANCY THAT I AM
YOU ARE - WERE AND WILL ALWAYS BE WRONG

BTW TWO WRONGS DON'T MAKE A RIGHT CLOSET BOY

YOU ARE TOM HORNE ALIAS THE DONKEY

A HARRASER A TROUBLEMAKER AND A JUDGEMENTAL TEMPERAMENTAL TROLL

AGAIN ROY ONLY ABUSED YOU AND JEALOUS TROLLS LIKE YOU ALL YOU DID WAS
MALIGN HIM AFTER HE CORRECTED YOU

YOU COULDN'T STAND THAT A TECH HAD CALLED YOU ON A TOPIC AND HE WAS
CORRECT " NOT YOU" JUST AS YOU ARE NOT CORRECT NOW

GO GET THERAPY AND CUT YOUR SUB HUMAN CRAP SLINGING OUT IT IS VERY
UNPLEASANT TO THE OTHERS
YOU ARE SICK VERY SICK AND TOTALLY WRONG


I AM PROTUES
 
On Wed, 11 Mar 2009 06:49:20 -0700 (PDT), proteusiiv@gmail.com wrote:

YOU COULDN'T STAND THAT A TECH HAD CALLED YOU ON A TOPIC AND HE WAS
CORRECT " NOT YOU" JUST AS YOU ARE NOT CORRECT NOW

Quote and post the proof of this claim. Roy never corrected any person
in this group.

Also, you have no clue who I am as many hate you here, and you have
pooled them al together, thinking they are all one person. You are a
complete idiot.

What happened to your WebTardTV account, boy?

Oh... that's right... they did not like the horseshit you post either!

If google did not have so many like you being abusive, your account with
them would already be gone as well.

It isn't that hard, considering the stupid crap you post.
 
On Mar 11, 9:49 am, proteus...@gmail.com wrote:
On Mar 10, 8:03 pm, Archimedes' Lever <OneBigLe...@InfiniteSeries.Org
wrote:

On Tue, 10 Mar 2009 05:41:07 -0700 (PDT), proteus...@gmail.com wrote:
On Mar 9, 7:16 pm, Archimedes' Lever <OneBigLe...@InfiniteSeries.Org
wrote:
On Mon, 9 Mar 2009 06:21:18 -0700 (PDT), proteus...@gmail.com wrote:

I HAVE DESIGNED MICRO PARTS ALRIGHT

  Sure you have.

OF COURSE I HAVE YOU FAGGOTY CALIFORNIAN FORNICATOR
I HAVE A GREAT TEAM AND HAVE SPECIFIED METALALURGY FOR PARTS FOR THEM
AS WELL

 That might even be believable if you could actually spell the word
metallurgy.

YOU THOUGHT YOU KNEW EVERYTHING & EVERYONE IN THE GROUP

 Nope.  Never made any such statement.  I do know an idiot when one
posts, however, idiot.

YOU ERRED YOU  ARE WROYNG
YOU HAVE CAUSE LOTS OF DAMAGE
YOU ARE A GREATER PROBLEM THAN YOU THINK AND HAVE BEEN FOUND NOT WORTH
THE EFFORTS

  Giving up so soon?  What a pussy.

YOU MUST MAKE AMENDS OR YOU WILL NEVER REACH A COLLECTIVE GOAL AGAIN

 I do fine every day.  The company I work for will NEVER have hard
economic times.

 The building owner you work for might want a cheaper Bldg Supr, however.
You fail in two areas.  Brains, and ambition.

I AM PROTEUS

  No, you are Roy, an utter idiot,<=THIS IS WHAT GOT YOU PEGGED THE FAGGOT OF THE GRPOUP]  that hasn't stopped crying since the
group saw you for what you are.

WHATEVER OR WHOM EVER YOU FANCY THAT I AM
YOU ARE - WERE AND WILL ALWAYS BE WRONG

BTW TWO WRONGS DON'T MAKE A RIGHT CLOSET BOY

YOU ARE TOM HORNE ALIAS THE DONKEY

A HARRASER A TROUBLEMAKER AND A JUDGEMENTAL TEMPERAMENTAL TROLL

AGAIN ROY ONLY ABUSED YOU AND JEALOUS TROLLS LIKE YOU ALL YOU DID WAS
MALIGN HIM AFTER HE CORRECTED YOU

YOU COULDN'T STAND THAT A TECH HAD CALLED YOU ON A TOPIC AND HE WAS
CORRECT " NOT YOU" JUST AS YOU ARE NOT CORRECT NOW

GO GET THERAPY AND CUT YOUR SUB HUMAN CRAP SLINGING OUT IT IS VERY
UNPLEASANT TO THE OTHERS
YOU ARE SICK VERY SICK AND TOTALLY WRONG

I AM PROTUES
Sorry Wrong! Thank you for playing. I have never had a need to hide
my identity from anyone. I sign my posts with my real name. Anytime
you would like to take a break from the name calling you might try
telling me; on list or off; what I said that makes you so hostile
towards me. I simply cannot recall having personally attacked you or
anyone else here or anywhere else on Usenet.

--
Tom Horne
 
On Mar 12, 11:56 am, Tom Horne <horn...@gmail.com> wrote:
On Mar 11, 9:49 am, proteus...@gmail.com wrote:





On Mar 10, 8:03 pm, Archimedes' Lever <OneBigLe...@InfiniteSeries.Org
wrote:

On Tue, 10 Mar 2009 05:41:07 -0700 (PDT), proteus...@gmail.com wrote:
On Mar 9, 7:16 pm, Archimedes' Lever <OneBigLe...@InfiniteSeries.Org
wrote:
On Mon, 9 Mar 2009 06:21:18 -0700 (PDT), proteus...@gmail.com wrote:

I HAVE DESIGNED MICRO PARTS ALRIGHT

  Sure you have.

OF COURSE I HAVE YOU FAGGOTY CALIFORNIAN FORNICATOR
I HAVE A GREAT TEAM AND HAVE SPECIFIED METALALURGY FOR PARTS FOR THEM
AS WELL

 That might even be believable if you could actually spell the word
metallurgy.

YOU THOUGHT YOU KNEW EVERYTHING & EVERYONE IN THE GROUP

 Nope.  Never made any such statement.  I do know an idiot when one
posts, however, idiot.

YOU ERRED YOU  ARE WROYNG
YOU HAVE CAUSE LOTS OF DAMAGE
YOU ARE A GREATER PROBLEM THAN YOU THINK AND HAVE BEEN FOUND NOT WORTH
THE EFFORTS

  Giving up so soon?  What a pussy.

YOU MUST MAKE AMENDS OR YOU WILL NEVER REACH A COLLECTIVE GOAL AGAIN

 I do fine every day.  The company I work for will NEVER have hard
economic times.

 The building owner you work for might want a cheaper Bldg Supr, however.
You fail in two areas.  Brains, and ambition.

I AM PROTEUS

  No, you are Roy, an utter idiot,<=THIS IS WHAT GOT YOU PEGGED THE FAGGOT OF THE GRPOUP]  that hasn't stopped crying since the
group saw you for what you are.

WHATEVER OR WHOM EVER YOU FANCY THAT I AM
YOU ARE - WERE AND WILL ALWAYS BE WRONG

BTW TWO WRONGS DON'T MAKE A RIGHT CLOSET BOY

YOU ARE TOM HORNE ALIAS THE DONKEY

A HARRASER A TROUBLEMAKER AND A JUDGEMENTAL TEMPERAMENTAL TROLL

AGAIN ROY ONLY ABUSED YOU AND JEALOUS TROLLS LIKE YOU ALL YOU DID WAS
MALIGN HIM AFTER HE CORRECTED YOU

YOU COULDN'T STAND THAT A TECH HAD CALLED YOU ON A TOPIC AND HE WAS
CORRECT " NOT YOU" JUST AS YOU ARE NOT CORRECT NOW

GO GET THERAPY AND CUT YOUR SUB HUMAN CRAP SLINGING OUT IT IS VERY
UNPLEASANT TO THE OTHERS
YOU ARE SICK VERY SICK AND TOTALLY WRONG

I AM PROTUES On Thursday

Sorry Wrong!  Thank you for playing.  I have never had a need to hide
my identity from anyone.  I sign my posts with my real name.  Anytime
you would like to take a break from the name calling you might try
telling me; on list or off; what I said that makes you so hostile
towards me.  I simply cannot recall having personally attacked you or
anyone else here or anywhere else on Usenet.

--
Tom Horne- Hide quoted text -

- Show quoted text -
NO INSTEAD MYSTERIOUSLY TROLLS STARTED THEIR MURDEROUS RAMPAGE ON USER
ROYKEY AFTER YOU FLUBBED A BONDING POST

I AM PROTEUS
 

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