Re: TI-H: Re: Voltage at 4.4v ???

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Re: TI-H: Re: Voltage at 4.4v ???

Richard Piotter wrote:

> I use duracels only because of the massive power they throw out. No
> rechargable, not even alkalines put out duracel power. I don't want to
> cause a fuss, but I have tested battery runtime and power and duracel
> beat everything. I probably got those 5v readings because of the power a
> duracel puts out. Rechargables only run at 1.2 volts, not 1.5 like a
> high power alkaline. That low recharable power may be going low enough
> for the drop out voltage to kick in. That is probably why you have a low
> current.

Welp, I'll warn you now... I'm gonna be pretty nasty about this post.
;-|

Either my messages aren't getting out... or none of you are reading
them.
So it looks like I get to explain this again. Either that, or you should
go pick up a cheap Electronics 101 book and learn the basics first.

That drop out voltage doesn't ever "kick in" -- It is ALWAYS present. I
don't
care if you're powering the regulator with 35 volts at 280 amps or 9
volts
at 50 mA... the regulator will ALWAYS drop its drop out voltage (The
drop out
voltage itself will vary based on current draw on the regulator,
however)
So essentially using your beloved Duracells doesn't make any damned
difference.
If your duracells are only putting out 6V, it still isn't any good. I
think
you are confusing "power" and "voltage" -- Power is essentially V*A
(Watts
are a unit of power) and voltage is a measurment of the difference in
electron potential. In any case, battery "power" is not the word for
what you're trying to describe.. you are measuring power/time ... 
I.E. the amount of time the battery lasts.

Additionally, you are incorrect in your description of Duracells.
Duracells
-=ARE=- Alkaline batteries, just like the pink bunny batts. The
differences
between the batteries are fairly minor and you simply cannot compare
them
since you have no idea how long each of the batts you tested was on the
store shelf. Additionally... MOST batteries are renewable -- Its just
that
normal alkalines do not recharge well at all. NiCds are specialized for
being rechargable... NiMH are ever better than NiCds. The renewables are
probably alkalines that are just modified slightly to make them take a
charge
better. Personally, I don't think the renewables are worth the cardboard
they
come in.

Additionally, 5 NiCd cells are usually combined to make a 6 volt pack --
But when fully charged this pack may measure as much as 8 volts. The
NiCds
when fully charged are usually at at least 1.5 volts.. The problem is
that
the NiCd discharge curve is much different from the Alkaline discharge
curve. Thus, the pack is at 6 volts after only a few minutes of use. In
any
case, you simply cannot feed a 7805 with 6 volts! It just doesn't
freaking
work!!!!!

I don't care if you ARE getting 5 volts out of a 7805 with your
duracells...
that 5 volts is at no LOAD (your DMM is extremely high impedence) I'm
betting
that with your cartridges in there that voltage would go down to 4.5 or
more..
and God knows what when you started producing switching noise.
 
> I still agree with the data though, switch to the National VR.

Well, thank God... that's what saved you from my flaming wrath. ;-)

> Also, duracells are great with the SPinTerface port.

As are any battery...

BTW, thanks for taking that damned 12 line "R" out of your sig. I've
always
thought that large sigs are the poster's attempt to make up for a lack
of
size elsewhere.... ;-)

Bryan Rittmeyer
bryanr@flash.net
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