Maker Pro
Maker Pro

ST LM324N anyone have any schematics

R

Robert Latest

Jan 1, 1970
0
Tim said:
LM324N http://www.ortodoxism.ro/datasheets/stmicroelectronics/2156.pdf

can i make a four channel audio amp with this chip?
Yes.

left tweeter / right tweeter / left woofer / right woofer.

It may not be loud enough for your taste. I mean, you even provided a
datasheet; why don't you read it and do some math to determine the available
output power?
This would be my first electronics project but i have a scope and want
to learn.

It would be better if you had a book rather than the scope. Get a hobby
electronics book or magazine with some example circuits and build a dozen of
those. Then modify the circuits to fit your needs. Finally, start designing
on your own. That's what got most of us started here.

Of course the 'Net is full of hobby stuff as well, but it often takes some
experience to judge if something is hard or easy to build, or if it is
downright bogus. Printed publications specifically geared at the hobbyist
are better in that regards. Elektor used to have those "300+ circuits"
books, maybe they're still available.

robert
 
K

krw

Jan 1, 1970
0
LM324N http://www.ortodoxism.ro/datasheets/stmicroelectronics/2156.pdf

can i make a four channel audio amp with this chip? left tweeter /
right tweeter / left woofer / right woofer.

Sure, but it would be rather horrid. You're not going to get any
power out of it and the crossover distortion of a LM324 is pretty
bad. The frequency response won't be anything to write home about
either.

You could put a complimentary pair of transistors on the output.
This will get you some more power but the crossover distortion will
still be bad (and frequency response worse).
This would be my first electronics project but i have a scope and want
to learn.

It's a good project to learn with.
 
M

MooseFET

Jan 1, 1970
0
[... LM324 for audio ...]
You could put a complimentary pair of transistors on the output.
This will get you some more power but the crossover distortion will
still be bad (and frequency response worse).

No, the frequency responce will be bad and the crossover distortion
worse.

Vcc
!
Signal ------!+\ !/
! >-------+-----! NPN
---!-/ ! !\e
! ! !
------+---------------+------- Out
! ! !
=== ! !/e
! +------! PNP
! ! !\
GND--/\/\-+-/\/\-- GND

Forcing the Lm324 to always pull up helps a bit.
 
J

John Larkin

Jan 1, 1970
0
LM324N http://www.ortodoxism.ro/datasheets/stmicroelectronics/2156.pdf

can i make a four channel audio amp with this chip? left tweeter /
right tweeter / left woofer / right woofer.

This would be my first electronics project but i have a scope and want
to learn.
thanks!

LM324 is terrible for audio. Use, say, an LF347. But 1/4 of a little
opamp will never give you enough power to drive a speaker to useful
levels. For that you need big parts.

John
 
E

Eeyore

Jan 1, 1970
0
Tim said:
LM324N http://www.ortodoxism.ro/datasheets/stmicroelectronics/2156.pdf

can i make a four channel audio amp with this chip? left tweeter /
right tweeter / left woofer / right woofer.

This would be my first electronics project but i have a scope and want
to learn.

The first thing I'd suggest if you want decent audio quality is to avoid using
the LM324. It's a really horrid op-amp.

There are plenty of really good op-amps designed for high quality audio. You
don't specify what supply voltages you intend to use but I'll start by
suggesting the NE5532 dual op-amp. It's been around for over 30 years and cost a
fortune when it came out. These days it's made by the bucketful and you can even
buy them on ebay in small quantities for under $1 ea.

Graham
 
G

GregS

Jan 1, 1970
0
The LM324 is an *op-amp* not a power amp. It does not drive speakers.

The 324 does source more current than most op-amps. One could use a quLITY amp
than can drive 600 ohm loads, but the thing to do is use a device made
for speaker loads. There are tons of those such as............
http://www.national.com/pf/LM/LM384.html

greg
 
M

MooseFET

Jan 1, 1970
0
LM324 is terrible for audio. Use, say, an LF347. But 1/4 of a little
opamp will never give you enough power to drive a speaker to useful
levels. For that you need big parts.

John


The LT1230 will drive 30mA.

0.03^2*8 = 7.2mW

That is *way* louder than anyone needs for rap-music.
 
K

krw

Jan 1, 1970
0
[... LM324 for audio ...]
You could put a complimentary pair of transistors on the output.
This will get you some more power but the crossover distortion will
still be bad (and frequency response worse).

No, the frequency responce will be bad and the crossover distortion
worse.

Ok. ;-)
Vcc
!
Signal ------!+\ !/
! >-------+-----! NPN
---!-/ ! !\e
! ! !
------+---------------+------- Out
! ! !
=== ! !/e
! +------! PNP
! ! !\
GND--/\/\-+-/\/\-- GND

Forcing the Lm324 to always pull up helps a bit.

I've always forced the LM324 into the dust bin[*], but...

[*] I have used them for DC applications.
 
R

Rich Grise

Jan 1, 1970
0
The LT1230 will drive 30mA.

0.03^2*8 = 7.2mW

That is *way* louder than anyone needs for rap-music.

There's no such thing as rap "music". Music has a melody, while rap is
just noise. You might as well beat on a hollow log while dancing around
a boiling missionary. (not that there's anything wrong with boiling
missionaries!) ;-)

Thanks,
Rich
 
S

Spehro Pefhany

Jan 1, 1970
0
There's no such thing as rap "music". Music has a melody, while rap is
just noise. You might as well beat on a hollow log while dancing around
a boiling missionary. (not that there's anything wrong with boiling
missionaries!) ;-)

Thanks,
Rich

I'm sure the missionaries have a different position on that. Last time
I was talking to a missionary I mentioned that kid is taking a course
primarily intended for "heritage language" students. He got this
shocked expression on his face.. though I said it was intended for
"heretics".


Best regards,
Spehro Pefhany
 
S

Spehro Pefhany

Jan 1, 1970
0
[... LM324 for audio ...]
You could put a complimentary pair of transistors on the output.
This will get you some more power but the crossover distortion will
still be bad (and frequency response worse).

No, the frequency responce will be bad and the crossover distortion
worse.

Ok. ;-)
Vcc
!
Signal ------!+\ !/
! >-------+-----! NPN
---!-/ ! !\e
! ! !
------+---------------+------- Out
! ! !
=== ! !/e
! +------! PNP
! ! !\
GND--/\/\-+-/\/\-- GND

Forcing the Lm324 to always pull up helps a bit.

I've always forced the LM324 into the dust bin[*], but...

[*] I have used them for DC applications.

Ah, but they're the very best op-amp on the market at that price
level. (The worst too.)


Best regards,
Spehro Pefhany
 
K

krw

Jan 1, 1970
0
There's no such thing as rap "music". Music has a melody, while rap is
just noise. You might as well beat on a hollow log while dancing around
a boiling missionary. (not that there's anything wrong with boiling
missionaries!) ;-)
What do you have against the missionary position?
 
Top