A little help please regarding Amps?(LM324)

Thread Starter

nadjatee1996

Joined Aug 11, 2011
2
I have a LM324 Op-Amp, but to be honest, I have no idea how to use it...I understand a moderate amount about electronics, with the exception of reading schematics, but this project I'm making sounds simple enough. I just want to make a little amplifier for my speakers, so it can be a bit louder, I plan on using a few(or a lot) of 1.5v button batteries. Anyways, I got no idea how to use my LM324, I understand that 1in- and 1in+ yields a 1out, but my speakers have a + and - inputs, so how do I make that work?Also, the ground wire goes...where( a piece of plastic?)?
 

SgtWookie

Joined Jul 17, 2007
22,230
Well, you have the wrong IC for the job. The LM324 is a small signal amplifier, not an audio power amplifier. Also, it's only good at rather low frequencies; not something you'd really want to run audio through.

You could use an LM386; here's a datasheet for that amplifier:
http://www.national.com/ds/LM/LM386.pdf
See the example schematics in the datasheet.
It's not very powerful, but if you're using button batteries, you're not going to get much power out of them anyway.
 

Thread Starter

nadjatee1996

Joined Aug 11, 2011
2
1) would it be loud enough? I wnat it to be pretty loud, not SUPER loud, but decently enough
2) is it sold at RadioShacks?

Also, I was wrong, it's gonna be powered by my iTouch, not button batteries...
 

SgtWookie

Joined Jul 17, 2007
22,230
1) "Loud enough" is purely subjective; I have no clue what your speakers are, or what they are rated, or what you were powering them with before. An LM386 is a low power audio amp.

2) Yes.

3) I have absolutely no clue as to what voltage or power is available from an iTouch, which will have a large bearing on how loud the output will be.
 

Adjuster

Joined Dec 26, 2010
2,148
I have a LM324 Op-Amp, but to be honest, I have no idea how to use it...I understand a moderate amount about electronics, with the exception of reading schematics, but this project I'm making sounds simple enough. I just want to make a little amplifier for my speakers, so it can be a bit louder, I plan on using a few(or a lot) of 1.5v button batteries. Anyways, I got no idea how to use my LM324, I understand that 1in- and 1in+ yields a 1out, but my speakers have a + and - inputs, so how do I make that work?Also, the ground wire goes...where( a piece of plastic?)?
If you cannot read schematics, then I think you will need to learn to do so before you will be able to do much with electronics.

For anything but a really simple circuit, it is very difficult to describe how to connect something up in words. Understanding a verbal description of a circuit without reference to a diagram is also pretty hard work. The old saying that "a picture is worth a thousand words" applies very well to electronics.
 
Last edited:

Audioguru

Joined Dec 20, 2007
11,248
The output loudness from an LM386 power amplifier into an 8 ohm speaker when it has a 9v supply sounds the same as a cheap clock radio.
 
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