op-amps with AA batteries?

R

rabiticide

Guest
I am a novice trying to design simple circuits. Most of my ideas
require op-amps and are things I would like to run off AA batteries.
How does one get around the +/- 15 volts going into the op-amps?

P.S. I don't like all the spam. Can anyone write a virus to destroy
the spammers? It would be appreciated.
 
rabiticide wrote:
I am a novice trying to design simple circuits. Most of my ideas
require op-amps and are things I would like to run off AA batteries.
How does one get around the +/- 15 volts going into the op-amps?

P.S. I don't like all the spam. Can anyone write a virus to destroy
the spammers? It would be appreciated.
My off the shelf solution would be to use 2 batteries.
Click to expand...
Or with one opamp to produce a virtual ground(1/2 battery voltage),
or use a small switching supply to produce -battery.
and use rail to rail opamps, some of which go as low a 5volt minimum
supply total.
 
On Fri, 4 Sep 2009 16:27:01 -0700 (PDT), rabiticide
<rabiticide@gmail.com> wrote:

I am a novice trying to design simple circuits. Most of my ideas
require op-amps and are things I would like to run off AA batteries.
How does one get around the +/- 15 volts going into the op-amps?

P.S. I don't like all the spam. Can anyone write a virus to destroy
the spammers? It would be appreciated.
Click to expand...
Use some low-voltage opamps, and run them off +-1.5.

Or use a couple of 9 volt batteries, +-9 supplies.

Or build a complicated dc-dc converter to make +-15 from 1.5.

John
 
On Fri, 04 Sep 2009 16:27:01 -0700, rabiticide wrote:

I am a novice trying to design simple circuits. Most of my ideas require
op-amps and are things I would like to run off AA batteries. How does
one get around the +/- 15 volts going into the op-amps?

By using an op-amp that was designed later than ABOUT 30 YEARS AGO!!!!
Click to expand...

Or the LM10, which is 25 years old at the very least, and works down to a
supply voltage of 1.1V. Or the LM358, which has worked at supply
voltages down to 3V for just as long.

Or any of the innumerable 'new' low power op-amps. National lists one
that is supposed to work at 0.9V, which is end-of-life for one of your AA
cells. You probably want to use at least a pair of cells so you can use
a 1.8V supply amp; using four cells will open you up to a world of
possibilities.

--
www.wescottdesign.com
 
On 2009-09-04, rabiticide <rabiticide@gmail.com> wrote:
I am a novice trying to design simple circuits. Most of my ideas
require op-amps and are things I would like to run off AA batteries.
How does one get around the +/- 15 volts going into the op-amps?
Click to expand...
redesign the circuit to use less.

P.S. I don't like all the spam. Can anyone write a virus to destroy
the spammers? It would be appreciated.
Click to expand...
you can run some op-amps off 3V (+/- 1.5V supply)
eg: LM324 or LMV844
 
rabiticide wrote:
P.S. I don't like all the spam. Can anyone write a virus to destroy
the spammers? It would be appreciated.
Click to expand...

That spam is posted through Google Groups. You are helping the
spammers by posting through there, yourself. Find a real NNTP server and
you won't see much spam.


--
You can't have a sense of humor, if you have no sense!
 
"rabiticide" <rabiticide@gmail.com> wrote in message
news:ffc797bd-ce8b-40c8-afd8-78d754111d99@s21g2000prm.googlegroups.com...
I am a novice trying to design simple circuits. Most of my ideas
require op-amps and are things I would like to run off AA batteries.
How does one get around the +/- 15 volts going into the op-amps?

P.S. I don't like all the spam. Can anyone write a virus to destroy
the spammers? It would be appreciated.
Click to expand...
Try LM324 single rail (down to 3V) quad opamp.
 
On Sat, 5 Sep 2009, Michael A. Terrell wrote:

rabiticide wrote:

P.S. I don't like all the spam. Can anyone write a virus to destroy
the spammers? It would be appreciated.


That spam is posted through Google Groups. You are helping the
spammers by posting through there, yourself. Find a real NNTP server and
you won't see much spam.

Maybe more immediately, since other places that carry newsgroups do screen
Click to expand...
out the blatant spam, a lot less shows up elsewhere. One can at this
point pretty much know that someone complaining about "too much spam" is
using google. Not only is google the source of much of the spam, but
they display it, so it looks a lot worse at google than many real
newsservers.

I seem to recall that dejanews made a point of not archiving spam, dealing
with it the same way good ISPs do, but that would seem to have stopped
when google took over the archive, or at least at some point since.
They might not have so many search problems if they actually removed
the spam before archiving the messages.

Michael
 
Michael Black wrote:
On Sat, 5 Sep 2009, Michael A. Terrell wrote:

rabiticide wrote:

P.S. I don't like all the spam. Can anyone write a virus to destroy
the spammers? It would be appreciated.


That spam is posted through Google Groups. You are helping the
spammers by posting through there, yourself. Find a real NNTP server and
you won't see much spam.

Maybe more immediately, since other places that carry newsgroups do screen
out the blatant spam, a lot less shows up elsewhere. One can at this
point pretty much know that someone complaining about "too much spam" is
using google. Not only is google the source of much of the spam, but
they display it, so it looks a lot worse at google than many real
newsservers.

I seem to recall that dejanews made a point of not archiving spam, dealing
with it the same way good ISPs do, but that would seem to have stopped
when google took over the archive, or at least at some point since.
They might not have so many search problems if they actually removed
the spam before archiving the messages.
Click to expand...

Google Groups uses have to flag it before its removed, but are either
too lazy or too stupid to clean up their nest by clicking on 'Report
This'.

I have started using Bing instead of Google. Google adds any
possible spelling of your search terms, making it difficult or
impossible to track down some rare items. the sat maps are more up to
date on Bing, as well.


--
You can't have a sense of humor, if you have no sense!
 
On Sat, 05 Sep 2009 08:15:30 -0400, Michael A. Terrell wrote:

rabiticide wrote:

P.S. I don't like all the spam. Can anyone write a virus to destroy the
spammers? It would be appreciated.


That spam is posted through Google Groups. You are helping the
spammers by posting through there, yourself. Find a real NNTP server and
you won't see much spam.
Click to expand...
And when you leave Google, be sure to send a note to them and to at least
one of their advertisers about _why_ you don't want to use Google Groups
any more.

You can affect _some_ business people by an appeal to what's right; you
can affect _all_ business people by an appeal to their pocketbook.

--
www.wescottdesign.com
 
On Sat, 5 Sep 2009 12:36:22 -0700 (PDT), rabbitKiller
<rabiticide@gmail.com> wrote:

I will see about getting news elsewhere. I was on usenet in the early
90's but it's all different now. I will leave google now...
Thanks for all the op-amp advice, I am getting my ideas through a
Circuit "Encyclopedia" which has all +/- 15 op-amps and I am glad
there're other options....
Click to expand...
If all you want is text (no pr0n) Usenet, individual.net is only about
$15/year ($10EUR/year). The customer service is second to none.
 
I will see about getting news elsewhere. I was on usenet in the early
90's but it's all different now. I will leave google now...
Thanks for all the op-amp advice, I am getting my ideas through a
Circuit "Encyclopedia" which has all +/- 15 op-amps and I am glad
there're other options....
 
On Fri, 4 Sep 2009 16:27:01 -0700 (PDT), rabiticide
<rabiticide@gmail.com> wrote:

I am a novice trying to design simple circuits. Most of my ideas
require op-amps and are things I would like to run off AA batteries.
How does one get around the +/- 15 volts going into the op-amps?

P.S. I don't like all the spam. Can anyone write a virus to destroy
the spammers? It would be appreciated.
Click to expand...
Spam spam spam . . .
Spam spam spam . . .

Hey, what you want ain't a big deal.

You choose an amp that works with low voltage supply. (from national
or maxim or ...)

Then you bias the sucker(s) to 1/2 Vcc instead of ground and just do
what you want with the amps. In the old days they might "lock up" (go
to one or another supply rail and hang). These days? Amps are much
much better.

You only have to keep in mind the divided voltages your 'e dealing
with (assuming some exceed Vcc - protect the input pins).

In the 70's we were pushing 701s' to 5 volts (2.5 volts plus and
minus, and 747's to 4 volts).
--
 
On Sat, 5 Sep 2009 15:16:51 +0100, "Phil O. Sopher"
<invalid@invalid.invalid> wrote:

"rabiticide" <rabiticide@gmail.com> wrote in message
news:ffc797bd-ce8b-40c8-afd8-78d754111d99@s21g2000prm.googlegroups.com...
I am a novice trying to design simple circuits. Most of my ideas
require op-amps and are things I would like to run off AA batteries.
How does one get around the +/- 15 volts going into the op-amps?

P.S. I don't like all the spam. Can anyone write a virus to destroy
the spammers? It would be appreciated.

Try LM324 single rail (down to 3V) quad opamp.
Click to expand...
LM324 - Ick!
 
On Sat, 5 Sep 2009, rabbitKiller wrote:

I will see about getting news elsewhere. I was on usenet in the early
90's but it's all different now. I will leave google now...
Thanks for all the op-amp advice, I am getting my ideas through a
Circuit "Encyclopedia" which has all +/- 15 op-amps and I am glad
there're other options....

That's the problem people make, they don't look at the date of the
Click to expand...
book. It gets even worse with the internet, because there usually
isn't a date put on the schematics. So people who "just want to build
the circuit" have real problems, not because the parts are dated, but
because they don't realize it, and can't figure out why they can't
find the parts.

The classic was about a decade ago when it was relatively common
to see people asking about where to get tunnel diodes, they were far
more common than should have been. It was clear people were stumbling
on old schematics posted on the internet (who knows why someone bothered
to post schematics that used tunnel diodes on the internet in general
pools of schematics), presumably thought they were good to build since
they didn't have many parts, and then had problems finding tunnel diodes.

Old circuits aren't in themselves bad, but one has to be aware of their
age, since yes, low voltage/low current op-amps didn't arrive until a
certain point, and even after they were available they weren't commonly
used in hobby circuits.

Michael
 
On Sat, 05 Sep 2009 22:37:24 -0400, Michael Black wrote:

On Sat, 5 Sep 2009, rabbitKiller wrote:

I will see about getting news elsewhere. I was on usenet in the early
90's but it's all different now. I will leave google now... Thanks for
all the op-amp advice, I am getting my ideas through a Circuit
"Encyclopedia" which has all +/- 15 op-amps and I am glad there're
other options....

That's the problem people make, they don't look at the date of the book.
It gets even worse with the internet, because there usually isn't a
date put on the schematics. So people who "just want to build the
circuit" have real problems, not because the parts are dated, but
because they don't realize it, and can't figure out why they can't find
the parts.

The classic was about a decade ago when it was relatively common to see
people asking about where to get tunnel diodes, they were far more
common than should have been. It was clear people were stumbling on old
schematics posted on the internet (who knows why someone bothered to
post schematics that used tunnel diodes on the internet in general pools
of schematics), presumably thought they were good to build since they
didn't have many parts, and then had problems finding tunnel diodes.

Old circuits aren't in themselves bad, but one has to be aware of their
age, since yes, low voltage/low current op-amps didn't arrive until a
certain point, and even after they were available they weren't commonly
used in hobby circuits.

Michael
Click to expand...
So where can I get a few tunnel diodes?

:).

--
www.wescottdesign.com
 
Tim Wescott wrote:
So where can I get a few tunnel diodes?
Click to expand...

In the tunnel. Watch out for the trains, though. ;-)


--
You can't have a sense of humor, if you have no sense!
 
"krw" <krw@att.bizzzzzzzzzzz> wrote in message
news:0if5a5htr99o64jt7j3fbrklr6bkht9pab@4ax.com...
On Sat, 5 Sep 2009 12:36:22 -0700 (PDT), rabbitKiller
rabiticide@gmail.com> wrote:
I will see about getting news elsewhere. I was on usenet in the early
90's but it's all different now. I will leave google now...
Thanks for all the op-amp advice, I am getting my ideas through a
Circuit "Encyclopedia" which has all +/- 15 op-amps and I am glad
there're other options....
If all you want is text (no pr0n) Usenet, individual.net is only about
$15/year ($10EUR/year). The customer service is second to none.
Click to expand...
Or else try the free servers ...

motzarella (now known as eternal-september)
albasani
x-privat
aioe

aioe is the worst because you have a max of 25 postings
per day, or something like 5 in any 10-minute period after
which you get blacklisted. Not good when you subscribe to
53 fora!
 
On Mon, 7 Sep 2009 10:34:06 +0100, "Phil O. Sopher"
<invalid@invalid.invalid> wrote:

"krw" <krw@att.bizzzzzzzzzzz> wrote in message
news:0if5a5htr99o64jt7j3fbrklr6bkht9pab@4ax.com...
On Sat, 5 Sep 2009 12:36:22 -0700 (PDT), rabbitKiller
rabiticide@gmail.com> wrote:
I will see about getting news elsewhere. I was on usenet in the early
90's but it's all different now. I will leave google now...
Thanks for all the op-amp advice, I am getting my ideas through a
Circuit "Encyclopedia" which has all +/- 15 op-amps and I am glad
there're other options....
If all you want is text (no pr0n) Usenet, individual.net is only about
$15/year ($10EUR/year). The customer service is second to none.

Or else try the free servers ...

motzarella (now known as eternal-september)
albasani
x-privat
aioe
Click to expand...
Forget aioe.

aioe is the worst because you have a max of 25 postings
per day, or something like 5 in any 10-minute period after
which you get blacklisted. Not good when you subscribe to
53 fora!
Click to expand...
You'll get blacklisted on 90% of the NNTP clients, as well. Also not
good.
 
Okay, this is me, the OP, now I'm off of google, and everything looks
better from here.
 
You must log in or register to reply here.

Welcome to EDABoard.com

Sponsor

Back
Top