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battery hot swap.

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Brad

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Feb 23, 2008, 3:35:33 PM2/23/08
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The next step in our project is to be able to hot swap the batteries
on the device and continue to run with out any interruptions.
Currently we are using 4 AA batteries. Currently draw is about 200
mA.

Do any of you have any ideas for a solution for something like this
where we could pull the batteries out and continue running for about
30 seconds until fresh batteries are inserted?!

Thanks for any information.

-Brad

Jim Thompson

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Feb 23, 2008, 4:02:07 PM2/23/08
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Depends on what your definition of "running" is.

Voltage?

Maybe just a big-valued capacitor?

Or two sets of batteries?

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice:(480)460-2350 | |
| E-mail Address at Website Fax:(480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

America: Land of the Free, Because of the Brave

RFI-EMI-GUY

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Feb 23, 2008, 5:03:01 PM2/23/08
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Insufficient information to answer your question. What is the device?
200MA sounds like a lot of continuous current for AA batteries. Maybe
you need a NICAD or NIMH rechargeable to maintain the operation while
changing batteries. But then how do you know that the primary batteries
are ready to go?

--
Joe Leikhim K4SAT
"The RFI-EMI-GUY"©

"Treason doth never prosper: what's the reason?
For if it prosper, none dare call it treason."

"Follow The Money" ;-P

Message has been deleted

a7yvm1...@netzero.com

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Feb 23, 2008, 5:38:04 PM2/23/08
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On Feb 23, 5:21 pm, SoothSayer <SaySo...@TheMonastery.org> wrote:

>   Two set of batteries .  Switch in the new batteries on the load, switch
> out the old, and then the old can be replaced while the new, secondary
> set are already in service.  No extra cap bank circuits or storage
> circuits needed.
>
>   Or put a crank storage module on it between battery swaps, the crank
> bank would supply the needs.- Hide quoted text -
>
> - Show quoted text -

You can logically OR the two supplies through diodes, if you can live
with the drop.

Spehro Pefhany

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Feb 23, 2008, 5:46:54 PM2/23/08
to

Maybe you could use primary (eg. Lithium AA) cells with a long shelf
life just to supply that 200mA between changes. Usually, IME, with
that kind of situation the 'controller' powers down the stuff that
uses a lot of current, and just keeps enough stuff alive to maintain
the state. In that case, a double-layer capacitor may be enough.

Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
sp...@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

Eeyore

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Feb 23, 2008, 5:56:32 PM2/23/08
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Brad wrote:

Well ..... if you wanted to use a cap to store charge, @ 200 mA, in
order to get a droop of 1 volt over 30 secs then the cap would have to
be 30 x 200 milli farads = 6 Farads !

Looks like you need a small back-up battery.

Graham

Phil Allison

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Feb 23, 2008, 6:02:08 PM2/23/08
to

"RFI-EMI-GUY"

>
> 200MA sounds like a lot of continuous current for AA batteries.


** Not true at all.

The common Energizer E91 alkalines will run 6 to 8 hours at 200mA -
depending on what end voltage is OK.

NiMH AA cells could bring that up to 12 hours or more.


> Maybe you need a NICAD or NIMH rechargeable to maintain the operation
> while changing batteries.


** One could switch over to a 9 volt battery to hold up the supply while
replacing in AAs.


> But then how do you know that the primary batteries are ready to go?


** Bout the only way to do that reliably is to use NiMH AA cells and have a
strict routine of replacing them with a freshly recharged set every 8 to 10
hours.

...... Phil


Jim Thompson

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Feb 23, 2008, 6:04:00 PM2/23/08
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On Sat, 23 Feb 2008 14:38:04 -0800 (PST), a7yvm1...@netzero.com
wrote:

Or see how us big boys do it, take a look at...

PerfectDiodeForChargerIsolation.pdf

on the SED page of my website.

legg

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Feb 23, 2008, 6:12:16 PM2/23/08
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Using each new battery to push out each old battery reduces hold-up
time requirements.

RL

JosephKK

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Feb 23, 2008, 10:58:50 PM2/23/08
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I have seen 2 farad supercaps.

linnix

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Feb 23, 2008, 11:50:12 PM2/23/08
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You can get thousands F supercaps if necessary. For the size of 4 AA,
100F is possible (Wima supercap R 16x36x45 mm).

PeterD

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Feb 24, 2008, 9:12:26 AM2/24/08
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On Sun, 24 Feb 2008 03:58:50 GMT, JosephKK <quiett...@yahoo.com>
wrote:

At 6 volts?

sycochkn

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Feb 24, 2008, 11:00:40 AM2/24/08
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"Brad" <bradwill...@yahoo.com> wrote in message
news:bf72fc74-e9ab-4011...@i7g2000prf.googlegroups.com...

2 sets of battery holders?

Bob


Fred Bloggs

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Feb 24, 2008, 11:32:22 AM2/24/08
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Wrong buzzword, that's not a "hotswap" which has to do with plugging a
circuit into live power through some form of connector. The"swap" part
is close, but no cigar...


JosephKK

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Feb 24, 2008, 1:53:34 PM2/24/08
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Elna has standard product of 1 farad at 6.3 volts, and in excess of 100
F at 2.5 volts.

John Popelish

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Feb 24, 2008, 2:05:34 PM2/24/08
to
JosephKK wrote:
> PeterD wrote:

>>> I have seen 2 farad supercaps.
>>
>> At 6 volts?
>
> Elna has standard product of 1 farad at 6.3 volts, and in excess of 100
> F at 2.5 volts.

Put three of Epcos B49410B2506Q000 5000F 2.5 volt caps in
series for a 1666F 7.5 volt cap.
http://www.epcos.com/inf/20/35/ds/B49410B2506Q000.pdf
--
Regards,

John Popelish

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Martin Griffith

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Feb 24, 2008, 5:36:34 PM2/24/08
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On Sun, 24 Feb 2008 12:08:35 -0800, in sci.electronics.design
"JakTheHammer" <jakt...@aol.com> wrote:

>
>"Eeyore" <rabbitsfriend...@hotmail.com> wrote in message news:47C0A4A0...@hotmail.com...

>Your idea will work but costly. He doesn't need any big Cap, all he has to do is to make sure a new battery is full charged before swapping. Insert the new battery in first before removing the old battery. It's so simple task to ask.
>
>Jack
>
>
Tryv

<CR/LF>

occasionaly
>

martin

Michael A. Terrell

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Feb 24, 2008, 5:50:15 PM2/24/08
to
JakTheHammered wrote:
>
> You got no brain.


Aren't mirrors wonderful? People like you can prance and pose in
front of them all day, yet you still see that you are an idiot.


--
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

Phil Allison

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Feb 24, 2008, 6:15:13 PM2/24/08
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"Jak The Fuckwit Retard "

> You too have a funny sound.


** LOL - this asinine prick sounds like a

STEAMING GREAT FUCKWIT !!!


> Battery doesn't dictate the current draw,


** Err - where did I say otherwise ???

FUCKWIT !!!!!!

....... Phil


RFI-EMI-GUY

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Feb 24, 2008, 9:04:39 PM2/24/08
to
JakTheHammer wrote:
> "Eeyore" <rabbitsfriend...@hotmail.com> wrote in message news:47C0A4A0...@hotmail.com...
>>
> Your idea will work but costly. He doesn't need any big Cap, all he has to do is to make sure a new battery is full charged before swapping. Insert the new battery in first before removing the old battery. It's so simple task to ask.
>
> Jack
>
>
>
>
You a got no brain.

Michae  A. Terrell

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Feb 25, 2008, 6:33:16 AM2/25/08
to

"Phil Allison" <phila...@tpg.com.au> wrote in message news:62ec42F...@mid.individual.net...
JakTheHammer ID maybe forged, watch out when the real JackTheHammer comes in, you all will be wiped out. He's a real tiger!

JakTheHammer

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Feb 26, 2008, 2:57:27 PM2/26/08
to
On Feb 25, 3:33�am, Michae� A. Terrell <mike.temr...@earthlink.net>
wrote:
> "Phil Allison" <philalli...@tpg.com.au> wrote in messagenews:62ec42F...@mid.individual.net...
> Central Florida- Hide quoted text -

>
> - Show quoted text -

It's FUN kicking your Mizerable Ass, GregoryMorrow at
earthlink.net............You've been Impostering Hundreds of
Identities all over Usenet...........Now the REAL JakTheHammer is
going to HAMMER your Sick Ass.........Donchaknow............You
Demented, Insane Bastard...........

Eeyore

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Feb 26, 2008, 3:05:25 PM2/26/08
to

JosephKK wrote:

> Eeyore wrote:
> >
> > Well ..... if you wanted to use a cap to store charge, @ 200 mA, in
> > order to get a droop of 1 volt over 30 secs then the cap would have to
> > be 30 x 200 milli farads = 6 Farads !
> >
> > Looks like you need a small back-up battery.
>

> I have seen 2 farad supercaps.

They won't deliver 200mA though.

Graham


Eeyore

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Feb 26, 2008, 3:07:38 PM2/26/08
to

JakTheHammer wrote:

> He doesn't need any big Cap, all he has to do is to make sure a new battery is full charged before swapping. Insert the new battery in first before removing the old battery. It's so simple task to ask.

So what happens when there's a momentary break in power ? As there will be.

Graham

Jakthehammer

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Feb 26, 2008, 3:16:47 PM2/26/08
to
On Feb 24, 2:50�pm, "Michael A. Terrell" <mike.terr...@earthlink.net>
wrote:

> JakTheHammered wrote:
>
> > You got no brain.
>
> � �Aren't mirrors wonderful? �People like you can prance and pose in
> front of them all day, yet you still see that you are an idiot.

However, you are responding to an Imposter Post.........The Same Moron
that Imposters MY Identity on this NG is also Impostering YOUR
Identity...........I DON'T post to this group...........I'm only here
because Gregory Morrow <gregorymor...@earthlink.net> is all over
Usenet Impostering Hundreds of Identities and Google attributes His
Posts to me...........You'll find his Posts are DELETED from Google
because since it's MY Identity, I have the POWER to Delete them from
Google.............Complain to aoie.org.........

Jakthehammer

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Feb 26, 2008, 3:22:29 PM2/26/08
to
On Feb 24, 2:50�pm, "Michael A. Terrell" <mike.terr...@earthlink.net>
wrote:
> JakTheHammered wrote:
>
> > You got no brain.
>
> � �Aren't mirrors wonderful? �People like you can prance and pose in
> front of them all day, yet you still see that you are an idiot.

If you need the readout to file a complaint to aoie.org. here it
is.......

http://groups.google.com/group/sci.electronics.design/msg/d33fb5b9aa0d69dc?dmode=source

Michael A. Terrell

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Feb 26, 2008, 4:24:45 PM2/26/08
to

"JakTheHammer" <jakt...@aol.com> wrote in message
news:74df0779-f772-48fc...@e23g2000prf.googlegroups.com...
On Feb 25, 3:33?am, Michae? A. Terrell <mike.temr...@earthlink.net>

wrote:
> "Phil Allison" <philalli...@tpg.com.au> wrote in
> messagenews:62ec42F...@mid.individual.net...
>
> > "Jak The Fuckwit Retard "
>
> >>>> 200MA sounds like a lot of continuous current for AA batteries.
>
> >>> ** ?Not true at all.

>
> >>> The common Energizer E91 alkalines will run 6 to 8 hours at 200mA
> >>> ?-

> >>> depending on what end voltage is OK.
>
> >>> NiMH AA cells could bring that up to 12 hours or more.
>
> >>>> Maybe ?you need a NICAD or NIMH rechargeable to maintain the

> >>>> operation
> >>>> while changing batteries.
>
> >>> ** One could switch over to a 9 volt battery to hold up the
> >>> supply while
> >>> replacing in AAs.
>
> >>>> But then how do you know that the primary batteries are ready to
> >>>> go?
>
> >>> ** ?Bout the only way to do that reliably is to use NiMH AA cells

> >>> and
> >>> have a
> >>> strict routine of replacing them with a freshly recharged set
> >>> every 8 to
> >>> 10
> >>> hours.
>
> >> You too have a funny sound.
>
> > ** ?LOL ?- ? this asinine prick sounds like a
>
> > STEAMING ? GREAT ? FUCKWIT ?!!!

>
> >> Battery doesn't dictate the current draw,
>
> > ** ?Err ?- ?where did I say otherwise ????
>
> > ? FUCKWIT ?!!!!!!
>
> > ....... ? Phil

>
> JakTheHammer ID maybe forged, watch out when the real JackTheHammer
> comes in, you all will be wiped out. ?He's a real tiger!
>
> --
> ?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- Hide quoted text -
>
> - Show quoted text -

It's FUN kicking your Mizerable Ass, GregoryMorrow at
earthlink.net............You've been Impostering Hundreds of
Identities all over Usenet...........Now the REAL JakTheHammer is
going to HAMMER your Sick Ass.........Donchaknow............You
Demented, Insane Bastard...........

Oh JakTheHumburger.... Who is really Mizerable butt? Have your check
your end lately? Little Yak?

--
Service to my country? Been there, Done that, and I've got my DD214 to

disprove it.

Michael A. Terrell

unread,
Feb 26, 2008, 4:25:21 PM2/26/08
to

"Jakthehammer" <jakt...@aol.com> wrote in message
news:0a0bd242-dbc7-4b56...@b1g2000hsg.googlegroups.com...
On Feb 24, 2:50?pm, "Michael A. Terrell" <mike.terr...@earthlink.net>

wrote:
> JakTheHammered wrote:
>
> > You got no brain.
>
> ? ?Aren't mirrors wonderful? ?People like you can prance and pose in

> front of them all day, yet you still see that you are an idiot.

If you need the readout to file a complaint to aoie.org. here it
is.......

http://groups.google.com/group/sci.electronics.design/msg/d33fb5b9aa0d69dc?dmode=source


I already filed against that Bastard JakTheHammer, then I posted the
Funny muscle Stimulator's project. Can't you see it DumbAss?

--
Service to my country? Been there, Done that, and I've got my DD214 to

disprove it.

Michael A. Terrell

unread,
Feb 26, 2008, 4:25:45 PM2/26/08
to

"Jakthehammer" <jakt...@aol.com> wrote in message
news:7ea13ca1-9d7a-4be5...@e23g2000prf.googlegroups.com...
On Feb 24, 2:50?pm, "Michael A. Terrell" <mike.terr...@earthlink.net>

wrote:
> JakTheHammered wrote:
>
> > You got no brain.
>
> ? ?Aren't mirrors wonderful? ?People like you can prance and pose in

> front of them all day, yet you still see that you are an idiot.

However, you are responding to an Imposter Post.........The Same Moron
that Imposters MY Identity on this NG is also Impostering YOUR
Identity...........I DON'T post to this group...........I'm only here
because Gregory Morrow <gregorymor...@earthlink.net> is all over
Usenet Impostering Hundreds of Identities and Google attributes His
Posts to me...........You'll find his Posts are DELETED from Google
because since it's MY Identity, I have the POWER to Delete them from
Google.............Complain to aoie.org.........


Oh......That's interesting, I didn't know I'm such a dumbass. Thanks
for your alert.

--
Service to my country? Been there, Done that, and I've got my DD214 to

disprove it.

Jakthehammer

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Feb 29, 2008, 3:57:17 PM2/29/08
to
On Feb 26, 4:25�pm, "Michael�A. Terrell" <mike.temr...@earthlink.net>
wrote:
> "Jakthehammer" <jakthh...@aol.com> wrote in message

Greg, the "aioe.org" gives you away.........Terrell doesn't post from
"aioe.org".........Anyone can tell you're an Imposter by LQQKING at
the Posting Paths..........If anyone is the Victim of one of your
Imposter Posts, they can just send you a Nasty Email at your Original
Identity of gregorymorrow at earthlink.net............They can also
Complain to aioe.org............Y'see, Usenet is a Dying
Entity............Partially because of people like YOU that want to
fuck with everybody else............75% of the Usenet Posts are from a
Small Minority of Sick Jerks using Sockpuppets and Imposters to fuck
with people...........Sick Bastards like YOU have Ruined what used to
be a Good Medium of Exchange and
Discussion..........Donchaknow............

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