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'[EE] Eneloop short circuit current'
2011\01\10@031948 by V G

picon face
Hi all,

Approximately how much would you guys estimate a single fully charged
Eneloop's short circuit current to be?

I short circuited a single Eneloop with my ammeter and I don't know if I'm
reading this right, but it's only showing around 2.5 Amps. I would think the
current supply capability would be much higher than this

2011\01\10@034016 by Charles Craft

picon face
www.candlepowerforums.com/vb/showthread.php?t=79302

The flashlight and photography people seem to be the ones that obsess over battery details.

On 1/10/2011 3:19 AM, V G wrote:
> Hi all,
>
> Approximately how much would you guys estimate a single fully charged
> Eneloop's short circuit current to be?
>
> I short circuited a single Eneloop with my ammeter and I don't know if I'm
> reading this right, but it's only showing around 2.5 Amps. I would think the
> current supply capability would be much higher than this.
>

2011\01\10@044101 by RussellMc

face picon face
SW - IF YOU READ ANYTHING 'NUMERICAL' HERE AND GLOSS OVER IT BECAUSE
THE MOST BASIC MATH INVOLVED IS ANNOYING THEN YOU DO YOURSELF A
DISSERVICE.

If you read the following and it doesn't allow you to much better
understand your problem and answer your question then you need a brain
recondition :-). ie it's all here well enough, your brain is known
excellent when working well, ... .

Maximum current you should "ideally" draw would be that stated  by the
manufacturer as the maximum.

What did you find when you looked here ?
(As Mr Gaggle serves this up as the first hit (in NZ anyway) when you
search for Eneloop I know we can safely assume that you looked at it.)

          http://www.eneloop.info/

And especially, what did you conclude from the discharge graphs on
this page when you looked at as part of your
youdidlookatthispagebeforeaskingsoastonotlooktotallyuninformeddidn'tyou
procedures?

          http://www.eneloop.info/home/performance-details/discharge-current.html

_____

As a guide, an unused newish AA Alkaline should give 5A to 10A+ on
short circuit as you describe. If it doesn't then your test system is
wanting. Fully charged normal AA NimH of say 2000 mAh capacity will
give 5A - 10A+ on short circuit. Eneloop may differ BUT see graphs
above.

2.5 A is well below what I'd expect for a true short circuit current.

What you actually get when using an ammeter to "short circuit" the
battery will be modified by

- cell internal resistance

- meter lead resistance (usually minimal)

- meter plugs contact resistance (variable. Can be horrendous)

- Contact resistance to battery - you affect this greatly.

- VERY IMPORTANTLY, meter internal resistance. Can be very low or
surprisingly high, depending on meter.

If you 'wiggle' [tm] the meter plugs while measuring, does the current
change. If so, improve your plugs or use a better meter or at a
minimum use the max value.

Place a VOLT meter across the leads to the short-circuiting ammeter.
What is the battery voltage when it is being "short circuited". How
does that compare to what you'd expect and/or the graph I refer to
above.

Measure the voltage drop in the leads under test. (Can help to take
out the meter test plugs, wind a piece of wire around metal - reinsert
plug. May have mechanical  problems in some cases.

Pass 2A or more through ammeter from eg a current limited source with
an open circuit voltage of say 5 volt. Measure meter voltage drop. at
test lead ends. Meter resistance should be under 0.1 ohm and ideally
well under 0.1 ohm.

A loaded battery that delivers ABOUT 1 V to a load will supply 2A max
to 0.5 ohm, 10A max to 0.1 ohm.
The meter should have minimal effect on the measurement so R needs to be low.

Obtain/make a say ~~ 0.2 R resistor. Attach VOLT meter across it so
you don't need to hold it in place. Briefly place across Eneloop. What
is voltage?




On 10 January 2011 21:19, V G <spam_OUTx.solarwind.xTakeThisOuTspamgmail.com> wrote:
> Hi all,
>
> Approximately how much would you guys estimate a single fully charged
> Eneloop's short circuit current to be?
>
> I short circuited a single Eneloop with my ammeter and I don't know if I'm
> reading this right, but it's only showing around 2.5 Amps. I would think the
> current supply capability would be much higher than this.
>

2011\01\10@044425 by alan.b.pearce

face picon face
> I short circuited a single Eneloop with my ammeter and I don't know if I'm
> reading this right, but it's only showing around 2.5 Amps. I would think the
> current supply capability would be much higher than this.

Any current meter is not an internal short circuit, but an appreciable resistance. For example I recently fell into this trap using a Fluke 89-IV DMM, which I thought would have a minimal resistance in the current shunt - turned out to be over 0.5 ohm on the 0.5A range. Even on a moving coil meter expect to have a voltage drop of around 0.1V at full scale.

It will be the lead resistance and internal resistance of the meter that will be determining the current. If you can measure the battery voltage while measuring the current you will get a feel for just how high the resistance of your test set up is.
-- Scanned by iCritical.

2011\01\10@073447 by RussellMc

face picon face
> http://www.candlepowerforums.com/vb/showthread.php?t=79302
>
> The flashlight and photography people seem to be the ones that obsess
> over battery details.

Obsess is often a bit unfair when it comes to cameras.
A modern SLR may peak at close to 5 amps drain and flash recycle times
depend critically on battery current capacity.

On my A700 the internal flash recycle rates plummet when indicated
battery capacity is still 30% + when using internal LiIon battery - so
the camera knows.

Using external flash at an event, wedding etc with heavy use, the
removed "dead" batteries, whether NimH or Alkaline, are often hotter
than be held in the hand - say 60 - 70 C and maybe more.



          Russel

2011\01\10@181023 by V G

picon face
On Mon, Jan 10, 2011 at 4:44 AM, <.....alan.b.pearceKILLspamspam@spam@stfc.ac.uk> wrote:

> Any current meter is not an internal short circuit, but an appreciable
> resistance. For example I recently fell into this trap using a Fluke 89-IV
> DMM, which I thought would have a minimal resistance in the current shunt -
> turned out to be over 0.5 ohm on the 0.5A range. Even on a moving coil meter
> expect to have a voltage drop of around 0.1V at full scale.
>
> It will be the lead resistance and internal resistance of the meter that
> will be determining the current. If you can measure the battery voltage
> while measuring the current you will get a feel for just how high the
> resistance of your test set up is.
>

Ah. Then what would be a good way to measure short circuit current

2011\01\10@183308 by Kerry Wentworth

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face
A clamp on DC ammeter?  Or you could just draw a substantial current from the battery and measure how much the battery voltage drops.

For example, a battery measures 11.8 volts no load, and 11.65 when drawing 1 amp.  Internal resistance of the battery is .15V/1A, or .15 ohms.  11.8V/.15ohms = 78.66 amps.

Kerry


V G wrote:
{Quote hidden}

-- Internal Virus Database is out-of-date.
Checked by AVG Anti-Virus.
Version: 7.0.289 / Virus Database: 267.11.13 - Release Date: 10/6/05

2011\01\10@205115 by RussellMc

face picon face
> Ah. Then what would be a good way to measure short circuit current?

Reading my reply and doing what I said.


                  Russel

2011\01\11@054544 by RussellMc

face picon face
> Obtain/make a say ~~ 0.2 R resistor. Attach VOLT meter across it so
> you don't need to hold it in place. Briefly place across Eneloop. What
> is voltage?

What result did you get?


2011\01\11@055639 by alan.b.pearce

face picon face
> > Obtain/make a say ~~ 0.2 R resistor. Attach VOLT meter across it so
> > you don't need to hold it in place. Briefly place across Eneloop. What
> > is voltage?
>
> What result did you get?

If he got anything, I would suggest it would be a very hot hand ...

I am not sure I would recommend attempting a short circuit current test on these cells, but rather extrapolating the internal impedance from measuring volts and current simultaneously from the 2.5A or so that he knows he can draw.
-- Scanned by iCritical.

2011\01\11@062120 by Michael Watterson

face picon face
On 11/01/2011 10:56, .....alan.b.pearceKILLspamspam.....stfc.ac.uk wrote:
>>> Obtain/make a say ~~ 0.2 R resistor. Attach VOLT meter across it so
>>> you don't need to hold it in place. Briefly place across Eneloop. What
>>> is voltage?
>> What result did you get?
> If he got anything, I would suggest it would be a very hot hand ...
>
> I am not sure I would recommend attempting a short circuit current test on these cells, but rather extrapolating the internal impedance from measuring volts and current simultaneously from the 2.5A or so that he knows he can draw.
I don't believe the Internal Resistance is linear.
Self heating and Chemistry affects Internal Resistance vs current

2011\01\11@070608 by RussellMc

face picon face
> > > Obtain/make a say ~~ 0.2 R resistor. Attach VOLT meter across it so
> > > you don't need to hold it in place. Briefly place across Eneloop. What
> > > is voltage?
> >
> > What result did you get?

>  If he got anything, I would suggest it would be a very hot hand ...

About 5 Watt dissipation.
Any usual range of 'briefly" should suffice to protect adequately,
provided a 5W+ dissipation resistor was used. While one could have
added DTTAH / YMMV / do not stapel spindle bend fold or mutilate, keep
in a safe place, ride safely preserve nature never wear a helmet, ...
/ he will hopely by now be able to use I^2R V^2/r and Introductory
Common Sense 101, but maybe not.


> I am not sure I would recommend attempting a short circuit current test on these cells, but rather extrapolating the internal impedance from measuring volts and current simultaneously from the 2.5A or so that he knows he can draw.

Yah.
But what I suggested was quite a long way from a short circuit,
exceeded at best an example long term Eneloop data sheet figure by
about 33% and was well within the load range of real world
applications. DSLR cameras 9as noted) may draw that much. My flash
probably takes whatever it is fed.

I suggested 0.2 ohm and a parallel volmeter - thus eliminating ammeter
drop. Add to that a bit of contact resistance - not a lot extra.
At 1V that's <= 5A. At 1.1V <= 5.5A. At 1.2V <=  6A. I'd be surprised
if it actually managed that. It may.

The Eneloop data sheet that I provided a link to

www.eneloop.info/home/performance-details/discharge-current.html
better:
<http://www.eneloop.info/index.php?eID=tx_cms_showpic&file=uploads/pics/Discharge_Rate_Characteristic.gif&width=800m&height=600m&bodyTag=%3Cbody%20style%3D%22margin:0;%20background:%23fff;%22%3E&wrap=%3Ca%20href%3D%22javascript:close();%22%3E%20|%20%3C/a%3E&md5=c0f3ebef43fef7a8f2f61e201738408f>

shows a 4A continuous discharge capability - ~1.3V start, 1.2v at ~ 7
minutes, 1.15V at ~ 20 minutes, 1.1V at  25 mins, 1V at just under 30
minutes.
Delivered capacity close to 2000 mAh - impresive if true.

Wattage at the very start is 1.3V, 0.2R =~ 8.5W, 6.5 A
Possible. Unlikely

A good (lowish resistance) ammeter short circuiting a new reputable AA
Alkaline or SOME NimH will exceed 10A.

I actually sort used AA Alkalines this way. A QUICK /C on 10A+ range
will allow you to rapidly sort through a box of cells and rapidly rank
them. Too much treatment like this is definitely not going to be good
for the battery's health.


       R




> --
> Scanned by iCritical.
>
>

2011\01\11@075312 by Olin Lathrop

face picon face
V G wrote:
> Ah. Then what would be a good way to measure short circuit current?

Not really a good idea in the first place.  You are basically putting the
battery's voltage directly accross its internal resistance.  All the energy
the chemical to electrical reaction can muster is then dissipated as heat in
the same place.  Bad idea.  And what are you going to do with that
information anyway?

Wanting to know the battery's internal resistance is legitimate, but note
that at the special case of a short, it won't likely be close to what it is
in normal operation anyway.  If you really want to see what your batteries
can do, put a resistor accross them that should draw near their rated max
current, and measure the voltage drop accross the battery from open to high
current.  Since you know the external resistor and have measured the battery
voltage, you know the current.  The voltage drop at the battery terminals
divided by the current is the internal resistance *at that operating point*..
That still won't guarantee what it is at other operating points, but it's a
much more meaninful value than short circuit current.


********************************************************************
Embed Inc, Littleton Massachusetts, http://www.embedinc.com/products
(978) 742-9014.  Gold level PIC consultants since 2000

2011\01\11@084255 by Oli Glaser

flavicon
face
On 11/01/2011 12:05, RussellMc wrote:
> I suggested 0.2 ohm and a parallel volmeter - thus eliminating ammeter
> drop. Add to that a bit of contact resistance - not a lot extra.
> At 1V that's<= 5A. At 1.1V<= 5.5A. At 1.2V<=  6A. I'd be surprised
> if it actually managed that. It may.

Judging from the original link (seems very thorough comparison of various cells) posted by C.C which I checked out (eneloop 2000mAh attached) - looks like the eneloop managed 10A for around 9.4 mins, initially at around 1.1V dropping to 1V but holding there well. Seemed to be one of the best performance wise anyway - many others managed <5A .
Looking at the graphs was very informative, just the info I would be looking for if selecting a cell (various V/Ah curves at different discharge rates from around 0.5A to 10A or wherever the battery fails to sustain voltage - as M.W notes the resistance is not completely linear, looks to get to a certain point then drop rapidly with NiMh)
The above method suggested would seem a simple way to determine this reasonably accurately though, shouldn't be too hard (with a bit of c.s applied) It's probably what I would do.

2011\01\11@084536 by Oli Glaser

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part 1 103 bytes content-type:text/plain; charset="iso-8859-1" (decoded quoted-printable)

For some reason graph failed to attach...
Here it is.



part 2 15342 bytes content-type:image/gif; name="EneloopAA2000atVariousRates.gif" (decode)


part 3 181 bytes content-type:text/plain; name="ATT00001.txt"
(decoded base64)

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2011\01\11@092515 by RussellMc

face picon face
part 1 298 bytes content-type:text/plain; charset="iso-8859-1" (decoded quoted-printable)

That is a remarkably good set of cuves.
That battery is substantially superior in energy output at a given C
rating than about any I've seen.
At about C/4 - C/5 it's above 1.25V for perhaps 75% of its capacity.
Extremely good.


Russell

Eneloop AA.


part 2 15342 bytes content-type:image/gif; name="EneloopAA2000atVariousRates.gif" (decode)


part 3 181 bytes content-type:text/plain; name="ATT00001.txt"
(decoded base64)

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2011\01\11@171951 by V G

picon face
Update: I'm pretty sure my multimeter is messed up. I measured the current
my flashlight is taking and I get different values every time I touch the
leads to the light. I get anywhere from 0.2 A to around 1 A. I don't think
it's *how* I'm touching the leads to the light because no matter what the
reading is, I see the same brightness of the light, at a 0.2 A reading as
well as a 1 A reading

2011\01\11@172215 by V G

picon face
On Tue, Jan 11, 2011 at 5:19 PM, V G <EraseMEx.solarwind.xspam_OUTspamTakeThisOuTgmail.com> wrote:

> Update: I'm pretty sure my multimeter is messed up. I measured the current
> my flashlight is taking and I get different values every time I touch the
> leads to the light. I get anywhere from 0.2 A to around 1 A. I don't think
> it's *how* I'm touching the leads to the light because no matter what the
> reading is, I see the same brightness of the light, at a 0.2 A reading as
> well as a 1 A reading.


A possibility is that I could have damaged the current measuring circuitry
by short circuitng the Eneloop. The mutlimeter says 20 A max (unfused), and
I tested two Eneloops in series which *may* have forced through more than 20
Amps.

Oh well. It's a cheap multimeter anyway

2011\01\11@174647 by Carl Denk

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face
Yea, I know you said "unfused", but, Probably the meter has a 20 amp fuse inside. Take the battery out and look for screws. I blow the low ampage fuse in my meters pretty regularly. :(

On 1/11/2011 5:21 PM, V G wrote:
> On Tue, Jan 11, 2011 at 5:19 PM, V G<x.solarwind.xspamspam_OUTgmail.com>  wrote:
>
>    
>> Update: I'm pretty sure my multimeter is messed up. I measured the current
>> my flashlight is taking and I get different values every time I touch the
>> leads to the light. I get anywhere from 0.2 A to around 1 A. I don't think
>> it's *how* I'm touching the leads to the light because no matter what the
>> reading is, I see the same brightness of the light, at a 0.2 A reading as
>> well as a 1 A reading.
>>      
>
> A possibility is that I could have damaged the current measuring circuitry
> by short circuitng the Eneloop. The mutlimeter says 20 A max (unfused), and
> I tested two Eneloops in series which *may* have forced through more than 20
> Amps.
>
> Oh well. It's a cheap multimeter anyway.
>

2011\01\11@175124 by Bob Blick

face
flavicon
face

On Tue, 11 Jan 2011 17:19:34 -0500, "V G" said:
> Update: I'm pretty sure my multimeter is messed up. I measured the
> current
> my flashlight is taking and I get different values every time I touch the
> leads to the light. I get anywhere from 0.2 A to around 1 A. I don't
> think
> it's *how* I'm touching the leads to the light because no matter what the
> reading is, I see the same brightness of the light, at a 0.2 A reading as
> well as a 1 A reading.

The test leads are a likely suspect. Broken strands at the connections
can cause the resistance to vary wildly.

Bob

-- http://www.fastmail.fm - Send your email first class

2011\01\11@175817 by peter green

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face
Carl Denk wrote:
> Yea, I know you said "unfused", but, Probably the meter has a 20 amp
> fuse inside. Take the battery out and look for screws. I blow the low
> ampage fuse in my meters pretty regularly. My experiance with cheap-medium meters is that most of them don't have a fuse for the high current range. Just a peice of thick resistance wire directly between the terminals. The only meter i've seen with a fuse on the high current range is the agilent benchtop in my office at uni

2011\01\11@180544 by Mark Rages

face picon face
If you have ever wondered about the short circuit current of a 9V
battery, I suggest you watch this video:
http://www.youtube.com/watch?v=XOxMUZUJUS4

(also covers basic battery chemistry in an entertaining way.)

Regards,
Mark
markrages@gmail
-- Mark Rages, Engineer
Midwest Telecine LLC
@spam@markragesKILLspamspammidwesttelecine.co

2011\01\11@180827 by V G

picon face
On Tue, Jan 11, 2011 at 5:51 PM, Bob Blick <KILLspambobblickKILLspamspamftml.net> wrote:

> The test leads are a likely suspect. Broken strands at the connections
> can cause the resistance to vary wildly.


But regardless of the reading, the brightness stayed exactly the same. I
think I'd notice a change in brightness if there really was a difference of
0.8 Amps

2011\01\11@181523 by Olin Lathrop

face picon face
V G wrote:
> Update: I'm pretty sure my multimeter is messed up. I measured the
> current my flashlight is taking and I get different values every time
> I touch the leads to the light. I get anywhere from 0.2 A to around 1
> A. I don't think it's *how* I'm touching the leads to the light
> because no matter what the reading is, I see the same brightness of
> the light, at a 0.2 A reading as well as a 1 A reading.

There is a internal problem in the meter.  The 200mA reading is probably
right.  There is a bad connection somewhere in series with the current
shunt, but between the points where its voltage is measured.  If the meter
rotary switch is in series with the current shunt, it is the first suspect.
Better meters have a separate plug for the high current range just for this
reason.  Sometimes working the switch back and forth a few times with the
meter off wipes off some of the crud.  In your case, the crud probably got
there when you abused the meter trying to measure the short circuit battery
current earlier.


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(978) 742-9014.  Gold level PIC consultants since 2000

2011\01\11@181540 by V G

picon face
On Tue, Jan 11, 2011 at 6:05 PM, Mark Rages <RemoveMEmarkragesTakeThisOuTspamgmail.com> wrote:

> If you have ever wondered about the short circuit current of a 9V
> battery, I suggest you watch this video:
> http://www.youtube.com/watch?v=XOxMUZUJUS4


LOL! Forty 9 Volt batteries! HAHAHAH that was awesome. I was surprised she
didn't wear insulator insulating gloves or anything. I think 360 Volts could
have killed her if she slipped touched it

2011\01\11@181800 by Olin Lathrop

face picon face
V G wrote:
>> The test leads are a likely suspect. Broken strands at the
>> connections can cause the resistance to vary wildly.
>
> But regardless of the reading, the brightness stayed exactly the
> same. I think I'd notice a change in brightness if there really was a
> difference of 0.8 Amps.

I agree.  The fault is not in the test leads, since that would have to
actually change the current by a factor of 4 to get what you see.  However,
if the current shunt or something in series with it is flaky, then the
overall current need not change much to get very different readings because
you're dropping only a small part of the overall voltage in either case.


********************************************************************
Embed Inc, Littleton Massachusetts, http://www.embedinc.com/products
(978) 742-9014.  Gold level PIC consultants since 2000

2011\01\11@182710 by Oli Glaser

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On 11/01/2011 22:19, V G wrote:
> Update: I'm pretty sure my multimeter is messed up. I measured the current
> my flashlight is taking and I get different values every time I touch the
> leads to the light. I get anywhere from 0.2 A to around 1 A. I don't think
> it's *how* I'm touching the leads to the light because no matter what the
> reading is, I see the same brightness of the light, at a 0.2 A reading as
> well as a 1 A reading.

Sounds like there is a problem, but why use a flashlight to try to confirm it? (I assume you know different, but just in case you have some sophisticated flashlight with some clever control circuitry, or PWM etc)
Just to be sure, why not just use a battery + resistor to produce a predictable current. Or a bench supply if available.
Test on a few ranges too.
As Bob said though, dodgy leads/sockets sound like a distinct possibility.
Is the voltage (or resistance) working okay? Have you tried the test method suggested there? I think you would have far more chance of success that way. IME, cheap multimeters can be terrible at measuring current but *usually* not too bad with voltage.




2011\01\11@182757 by Isaac Marino Bavaresco

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Em 11/1/2011 21:08, V G escreveu:
> On Tue, Jan 11, 2011 at 5:51 PM, Bob Blick <spamBeGonebobblickspamBeGonespamftml.net> wrote:
>
>> The test leads are a likely suspect. Broken strands at the connections
>> can cause the resistance to vary wildly.
>
> But regardless of the reading, the brightness stayed exactly the same. I
> think I'd notice a change in brightness if there really was a difference of
> 0.8 Amps.


Not simply a 0.8A difference, but a 5 to 1 ratio. You surely would
notice a difference.

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2011\01\11@183208 by Carl Denk

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I've had at least 4 different manufacturer's meters, at best medium value meters. All have had fuses on both the high and low range amps. None are Fluke, BK, or Klein price range. Current meters are Greenlee 93-606, and UNI-T UT60A.  Within the last few days, I cleaned and lubed the rotary switch contacts on the Greenlee. It was intermittent staying on when turned off. :)

On 1/11/2011 5:58 PM, peter green wrote:
> Carl Denk wrote:
>    
>> Yea, I know you said "unfused", but, Probably the meter has a 20 amp
>> fuse inside. Take the battery out and look for screws. I blow the low
>> ampage fuse in my meters pretty regularly.
>>      
> My experiance with cheap-medium meters is that most of them don't have a
> fuse for the high current range. Just a peice of thick resistance wire
> directly between the terminals. The only meter i've seen with a fuse on
> the high current range is the agilent benchtop in my office at uni.
>

2011\01\11@183327 by V G

picon face
On Tue, Jan 11, 2011 at 6:26 PM, Oli Glaser <TakeThisOuToli.glaserEraseMEspamspam_OUTtalktalk.net> wrote:

> Sounds like there is a problem, but why use a flashlight to try to
> confirm it? (I assume you know different, but just in case you have some
> sophisticated flashlight with some clever control circuitry, or PWM etc)
>

You're absolutely right. There might be some control mechanism in my
flashlight - it's an LED flashlight with a Cree C3 emitter.


> Just to be sure, why not just use a battery + resistor to produce a
> predictable current.


I'll test this next and let you guys know.


> Or a bench supply if available.
> Test on a few ranges too.
> As Bob said though, dodgy leads/sockets sound like a distinct possibility..
> Is the voltage (or resistance) working okay? Have you tried the test
> method suggested there? I think you would have far more chance of
> success that way. IME, cheap multimeters can be terrible at measuring
> current but *usually* not too bad with voltage.


That's right - I've never had an issue measuring voltages.

Just a note - my multimeter *does* have two different sockets for current
measurement. One of them is labeled "mA", and the other is labeled "20 A
max", "unfused"

2011\01\11@185143 by Carl Denk

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face
Both my meters are labeled for both ranges as "FUSED". :) :)



On 1/11/2011 6:33 PM, V G wrote:
>
> That's right - I've never had an issue measuring voltages.
>
> Just a note - my multimeter *does* have two different sockets for current
> measurement. One of them is labeled "mA", and the other is labeled "20 A
> max", "unfused".
>

2011\01\11@190247 by Charles Craft

picon face
On 1/11/2011 6:32 PM, Carl Denk wrote:
> I've had at least 4 different manufacturer's meters, at best medium
> value meters. All have had fuses on both the high and low range amps.
> None are Fluke, BK, or Klein price range. Current meters are Greenlee
> 93-606, and UNI-T UT60A.  Within the last few days, I cleaned and lubed
> the rotary switch contacts on the Greenlee. It was intermittent staying
> on when turned off. :)
>
>    
I've got a Fluke meter that wants to stay on when in the Off position.
What did you lube the contacts with after you cleaned yours

2011\01\11@194642 by V G

picon face
On Tue, Jan 11, 2011 at 7:02 PM, Charles Craft <RemoveMEchuckseaspamTakeThisOuTmindspring.com>wrote:
>
> What did you lube the contacts with after you cleaned yours?


HAhahahah!






Wait. Are you being serious

2011\01\11@200412 by IVP

face picon face
> I think 360 Volts could have killed her if she slipped and touched it

Too right. That's > rectified mains voltage. I think 60VDC is about
where it gets dangerou

2011\01\11@234754 by RussellMc

face picon face
> > I think 360 Volts could have killed her if she slipped and touched it

12 VDC *has* killed

6  VDC coiuldand may have.

2 VDC may if you tried hard enough.


> Too right. That's > rectified mains voltage. I think 60VDC is about
> where it gets dangerous

About 50 VDC gets "usefully dangerous"

But a 12V car battery CAN kill you (by electrocution, as well as if it
is dropped on your head)
Would you be prepared, for say a $1000 (or GBP) wager, to rub your
chest with saturated salt solution, and then to lean with bare skin
across the terminals of a 12V car battery?
Or 6V?
Or 2V.

A contrived arrangement?
Maybe, but bare chests *  and car batteries may occur in  eg
maintenance situations. Sweat makes a passable imitation for "high
conductivity surface coating".
Maybe carrying a truck battery out to a truck on a hot summer day with
an unbuttoned shirt, or shirtless.
Think about how you MIGHT carry a very heavy truck battery. (I
wouldn't because, apart from shock aspects I've had too many battery
acid encounters to let one that close to my chest**.)

Regardless - people HAVE died from contact with 12V in "ideal" situations.

You could very likely manage it with a 1V or so source with enough effort!.

It took me several attempts to convince people working on a vintage
battery electric locomotive restoration that their >50V  to >> 50V
battery of N00 Ah rating really shouldn't be left with wiring exposed,
as was being done,based on photos and text in newsletters I was sent.
Every time I saw it mentioned or saw a photo I commented. After a
while it stopped happening - whether they fixed it is unknown - maybe
I just annoyed them too much :-)..

* Nothing to do with US 2nd amendment, which only relates to bare-arms.


     Russel

2011\01\12@041644 by alan.b.pearce

face picon face
> I've got a Fluke meter that wants to stay on when in the Off position.
> What did you lube the contacts with after you cleaned yours?

I have one of those too. I am sending it back for repair under the lifetime warranty.
-- Scanned by iCritical.

2011\01\12@075949 by RussellMc

face picon face
> I have one of those too. I am sending it back for repair under the lifetime warranty.

Too late. If it's dead its lifetime, and thus it's warranty. mi\ust
have expired.
No ?
:-)

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