chip swelling up and getting fried

[James Sweet]

"wylbur37" <wylbur37nospam@yahoo.com> wrote in message
news:8028c236.0409020128.29791983@posting.google.com...

For the typical flashlight battery (AAA, AA, C, D),
all of them are 1.5 volts, but how much current do they offer?
(I'm guessing it's around 100 to 150mA, and it varies according
to the type of load that's on it).

And does it differ according to the battery size?
(does a "D" cell offer more current than an "AA"?)
or is it just that the D lasts longer?

Batteries are rated in amp-hours, which is the amount of current that can be
supplied for an hour (within a certain range). Even the lowly AA alkaline
can probably supply over an amp for brief periods, a D will be capable of
much more. When you get talking rechargeables some of them can supply tens
of amps.

 

[CWatters]

Nicad cells are a different beast, and up to 20 or more amps can be drawn
short-term,

Way more than that even. 70A is possible and recent Sub C size NiMH cells
have been used at 150A (4 second bursts every 20 seconds until empty)

 

[Peter A Forbes]

On Fri, 03 Sep 2004 02:39:41 GMT, "James Sweet" <jamessweet@hotmail.com> wrote:

"wylbur37" <wylbur37nospam@yahoo.com> wrote in message
news:8028c236.0409020128.29791983@posting.google.com...
For the typical flashlight battery (AAA, AA, C, D),
all of them are 1.5 volts, but how much current do they offer?
(I'm guessing it's around 100 to 150mA, and it varies according
to the type of load that's on it).

And does it differ according to the battery size?
(does a "D" cell offer more current than an "AA"?)
or is it just that the D lasts longer?

Batteries are rated in amp-hours, which is the amount of current that can be
supplied for an hour (within a certain range). Even the lowly AA alkaline
can probably supply over an amp for brief periods, a D will be capable of
much more. When you get talking rechargeables some of them can supply tens
of amps.

Non-Nicad cells are rated in Milliampere-hours, but the rate of discharge is
very restricted, and I doubt you would get anything near an amp out of them due
to the high internal impedance. They are designed for very low discharge
currents.

Nicad cells are a different beast, and up to 20 or more amps can be drawn
short-term, in fact we have had battery pack links melted through
short-circuits.

I seem to remember that D cells are 4.5AH in Nicad and 15000 mAH in
Alkaline-Manganese, 0.6AH for AA Nicad and 1500mAH for A-M. In all cases the
Alkaline cells are much higher in nominal capacity, but that capacity is only
available at very low discharge rates.

Peter

--
Peter & Rita Forbes
diesel@easynet.co.uk
Engine pages for preservation info:
http://www.oldengine.org/members/diesel

 

[Watson A.Name - \"Watt Su]

"Roger Hamlett" <rogerspamignored@ttelmah.demon.co.uk> wrote in message
news:k0GZc.72$sB.34@newsfe5-win.ntli.net...

"wylbur37" <wylbur37nospam@yahoo.com> wrote in message
news:8028c236.0409020128.29791983@posting.google.com...
For the typical flashlight battery (AAA, AA, C, D),
all of them are 1.5 volts, but how much current do they offer?
(I'm guessing it's around 100 to 150mA, and it varies according
to the type of load that's on it).

And does it differ according to the battery size?
(does a "D" cell offer more current than an "AA"?)
or is it just that the D lasts longer?
Two seperate ratings involved. The 'current' is limited by the
internal
resistance of the battery, the resistance of the load, and by the way
the
chemistry behaves. A dead short across even a AA battery, can produce
currents over 10A, for a short time, with some battery designs (NiCad
in
particular). Yes, the available current does rise with battery size,
with
more volume for the chemistry, and areas/thicknesses for the
electrodes.
The second rating, is the mAHr rating. This gives a figure for how
much
current can be delivered for how long. This figure is normally based
upon
the current that will discharge the battery in 10 hours. So a battery
with
a 1000mAHr rating, should be able to deliver 0.1A, for 10 hours.
Now a typical AA Zinc-Cabon battery might offer perhaps 1000mAHr,
while a
D cell will perhaps offer 4000mAHr. Note that the latter implies a
'test'
current 4 times as high as that used on the smaller battery.
Some battery chemistries function better at high discharge rates than
others. So (for instance), a NiCad D battery, may well support
operation
at 50* it's 'ten hour' current, and still give perhaps 25% of the full
capacity, while designs like zinc-air, will only deliver low currents,
even into a dead short.
When multiple 'capacity' versions of the same battery exist, the extra
capacity is often gained at the cost of other features. So (for
instance),
on NiMh batteries, where versions with higher capacities exist, these
often show higher internal resistance (so will work less well at high
loads),

In my experience, the opposite is true. The newer high capacity AA
Ni-MH cells of 2000 mAH and higher have very low internal resistance,
and last longer in my digital camera than the older ones. And digital
cameras, especially mine, with autofocus and flash, use a lotta current,
probably much more than an amp at times. You might think, why does he
seem to imply that the length of time has something to do with the
internal resistance? Well, in this case, when the four AA cells start
to get discharged, the camera starts to do things like shut off the LCD
while the flash is recharging. And it takes longer to 'boot up' the
camera when the batteries are low. Finally the camera's LCD won't come
on and the battery symbol just flashes. Time for another set of freshly
charged AA cells. But the cells aren't discharged that bad, their
internal resistance has just gone up.

and increased 'self discharge' rates (they will run down quicker
when not in use).

Yeah, that seems to be the case. I've left charged batteries in my
camera case for a couple months and I notice they last a lot shorter
time in the camera. So now I'm putting a post-it on the battery
carrying case with the charging date. And I check them and recharge
when they've sat around a couple months.

A typical zinc-carbon D cell, delivering half an amp, will run for
perhaps
4 hours. A high quality alkaline manganese dioxide battery into the
same
load, will top 20 hours. The internal resistance of the D cell, will
typically be less than 0.2ohms, while the AA of the same type, may
well
have an internal resistance over 0.4ohm.
Generall, AA batteries offer some of the best volumetric, and
gravimetric
power output (pack the most 'power' into the least weight, and
volume).

Best Wishes

 

[Jerry G.]

Florescent or neon type tubes will glow if the RF is strong enough. The only
problem is that if the energy is strong enough to make something like this
glow, there may be speculation about the health concerns to people and
animals in the area of this emission.

--

Jerry G.
==========================


"Doyle" <dndowd13@charter.net> wrote in message
news:2b10adbe.0409020916.616b33d8@posting.google.com...
I am looking for a material that either glows or changes color in the
presence of RF energy. I have found nothing so far so any help at this
point would be appreciated.

Thanks,
Doyle

 

[Al]

In article <dnVZc.234945$iM.12075040@phobos.telenet-ops.be>,
"CWatters" <colin.watters@pandoraBOX.be> wrote:

Nicad cells are a different beast, and up to 20 or more amps can be drawn
short-term,

Way more than that even. 70A is possible and recent Sub C size NiMH cells
have been used at 150A (4 second bursts every 20 seconds until empty)

Many years ago I knew someone who worked at a cell manufacturing
company. There was, ahem, a certain amount of leakage at the gate. After
his car battery died, he used 6 "A" sized cells connected in series to
start his Volkwagen. Yes, it was in the days when they used the 6V
battery system.

Al

 

[Roger Gt]

"Jerry G." <jerryg50@hotmail.com> wrote in message
news:2pr050Fo49c1U2@uni-berlin.de...
: Florescent or neon type tubes will glow if the RF is strong
enough. The only
: problem is that if the energy is strong enough to make something
like this
: glow, there may be speculation about the health concerns to
people and
: animals in the area of this emission.
:

NOT really. Fear monger at work. Brief exposure is never a
problem at the low levels required to get a lamp to glow. I use a
18 watt tube, and it glows nicely with a transmitter with a 3 watt
output. NBD

 

[Mjolinor]

"Roger Gt" <not@here.net> wrote in message
news:Ay1_c.15509$Kb1.15307@newssvr29.news.prodigy.com...

"Jerry G." <jerryg50@hotmail.com> wrote in message
news:2pr050Fo49c1U2@uni-berlin.de...
: Florescent or neon type tubes will glow if the RF is strong
enough. The only
: problem is that if the energy is strong enough to make something
like this
: glow, there may be speculation about the health concerns to
people and
: animals in the area of this emission.
:

NOT really. Fear monger at work. Brief exposure is never a
problem at the low levels required to get a lamp to glow. I use a
18 watt tube, and it glows nicely with a transmitter with a 3 watt
output. NBD

Bettrer to warn and be wrong that not warn and be right.

When we have got 20 or so generations of people exposed to greater than
background RF then I will believe it does no harm but until then, at least
for me, it is not proven to do no damage.

 

[R Adsett]

In article <S02_c.435$bY2.289@newsfe2-gui.ntli.net>, mjolinor@hotmail.com
says...

"Roger Gt" <not@here.net> wrote in message
news:Ay1_c.15509$Kb1.15307@newssvr29.news.prodigy.com...

"Jerry G." <jerryg50@hotmail.com> wrote in message
news:2pr050Fo49c1U2@uni-berlin.de...
: Florescent or neon type tubes will glow if the RF is strong
enough. The only
: problem is that if the energy is strong enough to make something
like this
: glow, there may be speculation about the health concerns to
people and
: animals in the area of this emission.
:

NOT really. Fear monger at work. Brief exposure is never a
problem at the low levels required to get a lamp to glow. I use a
18 watt tube, and it glows nicely with a transmitter with a 3 watt
output. NBD



Bettrer to warn and be wrong that not warn and be right.

When we have got 20 or so generations of people exposed to greater than
background RF then I will believe it does no harm but until then, at least
for me, it is not proven to do no damage.
Just out of curiousity, what mechanism do you suggest that would cause

the damage you are warning against?

Robert

 

[Bob Myers]

"Mjolinor" <mjolinor@hotmail.com> wrote in message
news:S02_c.435$bY2.289@newsfe2-gui.ntli.net...

Bettrer to warn and be wrong that not warn and be right.

Not always; for instance, if your warning causes undue
concern, and THAT results injury or has other undesirable
consequences, then your warning could actually turn out
to do more harm than good.

What's best, of course, is that a warning, if any, comes
from someone who's reasonably sure that they're right.

When we have got 20 or so generations of people exposed to greater than
background RF then I will believe it does no harm but until then, at least
for me, it is not proven to do no damage.

It's awfully hard to prove a negative - not impossible, as
some mistakenly claim, but generally pretty difficult. The
problem in this particular case is that there already IS a good
deal of experience with people in fairly high-intensity RF
fields, and little or nothing in the way of evidence of a problem
(unless, of course, the intensity/frequency is sufficient to cause
damage through heating). RF radiation isn't ionizing, and to
date NOTHING has been proposed as a mechanism through
which any non-heating-related health problems could occur.

Bob M.

 

[The Phantom]

On 2 Sep 2004 02:28:01 -0700, wylbur37nospam@yahoo.com (wylbur37)
wrote:

For the typical flashlight battery (AAA, AA, C, D),
all of them are 1.5 volts, but how much current do they offer?
(I'm guessing it's around 100 to 150mA, and it varies according
to the type of load that's on it).

And does it differ according to the battery size?
(does a "D" cell offer more current than an "AA"?)
or is it just that the D lasts longer?

Go have a look here for the alkaline type cells:
http://data.energizer.com/datasheets/contents/alkconsumeroem.htm

and here for the NiMH cells:
http://data.energizer.com/datasheets/contents/nimh.htm

It's interesting to note that the internal resistance of the D
alkaline (173 milliohms) is larger than than that of the AA cells (146
milliohms).

It's also interesting to note that the volume of a D cell is 6.9 times
that of an AA cell, and the capacity of an alkaline D is 6.3 times
that of an alkaline AA (numbers taken from the Energizer site).

But the capacity of a NiMH D cell is only 3.7 times that of a NiMH AA
cell (calculated using 8500 mah for D cells, and 2300 mah for AA
cells, currently near the state of the art).

It looks like the battery folks have been really working hard to
squeeze more into the NiMH AA cells.

 

[Ken Weitzel]

The Phantom wrote:

On 2 Sep 2004 02:28:01 -0700, wylbur37nospam@yahoo.com (wylbur37)
wrote:


For the typical flashlight battery (AAA, AA, C, D),
all of them are 1.5 volts, but how much current do they offer?
(I'm guessing it's around 100 to 150mA, and it varies according
to the type of load that's on it).

And does it differ according to the battery size?
(does a "D" cell offer more current than an "AA"?)
or is it just that the D lasts longer?


Go have a look here for the alkaline type cells:
http://data.energizer.com/datasheets/contents/alkconsumeroem.htm

and here for the NiMH cells:
http://data.energizer.com/datasheets/contents/nimh.htm

It's interesting to note that the internal resistance of the D
alkaline (173 milliohms) is larger than than that of the AA cells (146
milliohms).

It's also interesting to note that the volume of a D cell is 6.9 times
that of an AA cell, and the capacity of an alkaline D is 6.3 times
that of an alkaline AA (numbers taken from the Energizer site).

But the capacity of a NiMH D cell is only 3.7 times that of a NiMH AA
cell (calculated using 8500 mah for D cells, and 2300 mah for AA
cells, currently near the state of the art).

It looks like the battery folks have been really working hard to
squeeze more into the NiMH AA cells.

Hi...

Think of capacity not in terms of volume, but
rather as a function of exposed surface area.

Ken

 

[James Sweet]

"The Phantom" <phantom@aol.com> wrote in message
news:8sohj0tm3mkap2hs832rbohnenlthe1nm7@4ax.com...

On 2 Sep 2004 02:28:01 -0700, wylbur37nospam@yahoo.com (wylbur37)
wrote:

For the typical flashlight battery (AAA, AA, C, D),
all of them are 1.5 volts, but how much current do they offer?
(I'm guessing it's around 100 to 150mA, and it varies according
to the type of load that's on it).

And does it differ according to the battery size?
(does a "D" cell offer more current than an "AA"?)
or is it just that the D lasts longer?

Go have a look here for the alkaline type cells:
http://data.energizer.com/datasheets/contents/alkconsumeroem.htm

and here for the NiMH cells:
http://data.energizer.com/datasheets/contents/nimh.htm

It's interesting to note that the internal resistance of the D
alkaline (173 milliohms) is larger than than that of the AA cells (146
milliohms).

It's also interesting to note that the volume of a D cell is 6.9 times
that of an AA cell, and the capacity of an alkaline D is 6.3 times
that of an alkaline AA (numbers taken from the Energizer site).

But the capacity of a NiMH D cell is only 3.7 times that of a NiMH AA
cell (calculated using 8500 mah for D cells, and 2300 mah for AA
cells, currently near the state of the art).

It looks like the battery folks have been really working hard to
squeeze more into the NiMH AA cells.

That and most rechargeable "D" cells are really just sub-C or even AA's in a
D shell. You can get real D cells but they're expensive.

 

[Mjolinor]

"R Adsett" <radsett@junk.aeolusdevelopment.cm> wrote in message
news:KJ2_c.187$84Z.150@news04.bloor.is.net.cable.rogers.com...

In article <S02_c.435$bY2.289@newsfe2-gui.ntli.net>, mjolinor@hotmail.com
says...

"Roger Gt" <not@here.net> wrote in message
news:Ay1_c.15509$Kb1.15307@newssvr29.news.prodigy.com...

"Jerry G." <jerryg50@hotmail.com> wrote in message
news:2pr050Fo49c1U2@uni-berlin.de...
: Florescent or neon type tubes will glow if the RF is strong
enough. The only
: problem is that if the energy is strong enough to make something
like this
: glow, there may be speculation about the health concerns to
people and
: animals in the area of this emission.
:

NOT really. Fear monger at work. Brief exposure is never a
problem at the low levels required to get a lamp to glow. I use a
18 watt tube, and it glows nicely with a transmitter with a 3 watt
output. NBD



Bettrer to warn and be wrong that not warn and be right.

When we have got 20 or so generations of people exposed to greater than
background RF then I will believe it does no harm but until then, at
least
for me, it is not proven to do no damage.
Just out of curiousity, what mechanism do you suggest that would cause
the damage you are warning against?

Robert

Is this addressed to me? I wasn't aware that I was warning against any.

 

[Bennet Williams]

Any brushed DC motor can be used as a generator. If you want a DC
generator, this motor will do the job. I would recommend checking the
condition of the brushes and commutator.

BRW

On 4 Sep 2004 08:19:15 -0700, veryfree123@hotmail.com (Watson A.Name)
wrote:

I scrounged this big F'ing motor out of the trash bin, looks like it
was a drive motor for a big copier or old mainframe reel to reel tape
drive. It has a grooved belt pulley on one end of the shaft, maybe
1.5" in diameter. The other end of the shaft has a big flywheel,
maybe 7 or 8" inches weighing several pounds and the whole motor
weighs maybe 30 pounds (13kg). Says 3560 RPM or something like that.
The end with the pulley has what looks like a tachometer on it. I
left it in my truck, since it's big (more like long and only 4" in
diameter) and heavy.

It takes 124VDC, yeah, DC, at 16.6 AMPS or something like that. I
have no idea why it has to be DC, since it's obviously from some big
heavy stationary equipment. After all, one can get different speeds
from an AC motor. Maybe it has to be continuously variable speed. In
any case, my thoughts were that it would make a great generator if it
has permanent magnets in it. I haven't had a chance to check it out,
or put a meter on it to see if it generates. That'll come later.
Maybe if I get a chance I'll take a pic and post it to ABSE. I'm just
wondering if anyone has worked with something like this, and if it
will make a decent generator.

 

[Tim Wescott]

Watson A.Name wrote:

I scrounged this big F'ing motor out of the trash bin, looks like it
was a drive motor for a big copier or old mainframe reel to reel tape
drive. It has a grooved belt pulley on one end of the shaft, maybe
1.5" in diameter. The other end of the shaft has a big flywheel,
maybe 7 or 8" inches weighing several pounds and the whole motor
weighs maybe 30 pounds (13kg). Says 3560 RPM or something like that.
The end with the pulley has what looks like a tachometer on it. I
left it in my truck, since it's big (more like long and only 4" in
diameter) and heavy.

It takes 124VDC, yeah, DC, at 16.6 AMPS or something like that. I
have no idea why it has to be DC, since it's obviously from some big
heavy stationary equipment. After all, one can get different speeds
from an AC motor. Maybe it has to be continuously variable speed. In
any case, my thoughts were that it would make a great generator if it
has permanent magnets in it. I haven't had a chance to check it out,
or put a meter on it to see if it generates. That'll come later.
Maybe if I get a chance I'll take a pic and post it to ABSE. I'm just
wondering if anyone has worked with something like this, and if it
will make a decent generator.

Easy variable-speed control of AC motors has only come recently, and
there are still a lot of brushed DC motors sold because of their ease of
use.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

 

[R Adsett]

In article <HTl_c.15693$ov.14644@newssvr27.news.prodigy.com>,
Not@here.net says...

"Mjolinor" wrote
: "R Adsett" wrote
: > mjolinor wrote
: > > "Roger Gt" wrote
: > > > "Jerry G." wrote

: > > > : Florescent or neon type tubes will glow if the RF is
strong
: > > > enough. The only
: > > > : problem is that if the energy is strong enough to make
something
: > > > like this
: > > > : glow, there may be speculation about the health concerns
to
: > > > people and
: > > > : animals in the area of this emission.

It was intended to "Jerry G." who seems to think it is dangerous
to breath the air!
Mostly, but since the suggestion was raised (maybe half in jest?) that 20

generations would need to pass w/o effect before considering higher than
background safe I was curious as to what sort of effect was envisioned
that would not be visible until nearly that length of time had passed.

Robert

 

[Mjolinor]

There is NO proof that there is any harm done by the low level RF
from Cell phone. THAT has been proven.

I thought I had already said that.

 

[Clarence]

"Mjolinor" <mjolinor@hotmail.com> wrote in message
news:YzB_c.43$rj1.31@newsfe2-gui.ntli.net...
:
:
: > There is NO proof that there is any harm done by the low level
RF
: > from Cell phone. THAT has been proven.
: >
: >
:
: I thought I had already said that.
:
I thought you implied the data was incomplete.

 

[Mjolinor]

"Clarence" <No@No.Com> wrote in message
news:mWG_c.11927$QJ3.10315@newssvr21.news.prodigy.com...

"Mjolinor" <mjolinor@hotmail.com> wrote in message
news:YzB_c.43$rj1.31@newsfe2-gui.ntli.net...
:
:
: > There is NO proof that there is any harm done by the low level
RF
: > from Cell phone. THAT has been proven.
:
:
:
: I thought I had already said that.
:
I thought you implied the data was incomplete.

? Confusing me now. The data is incomplete and can never be any other way.
All that happens is that as time goes on then the chance of "no harm" being
correct increases, it is never proven.

The statement above says :-
It has been proven that there is no proof that any harm is done by RF
emmissions from a cell phone.

or, another way:-
As yet it has not been proven whether or not harm is done by radio
emmissions from cell phones.