Single supply op-amp configuration

[Mcfloyd]

I'll try to make my description quick so you don't tldr me.
So I worked on this project in school on a 6.5inch woofer.
I took it from an old computer set (creative) and the amp was dead.
I designed and built a new dual supply class ab stage amplifier with a low pass filter.

So now I don't have a supply, but want to use it for a home theater or computer set up, but passive sucks so I want to design a new single supply amp.

What's the best configuration, and the best IC's to use for this, and can I implement single-supply with a class ab output stage?

All I can ever find on the web is dual supply for gainclones in car audio, but I'm not using it for my car.
Thanks for the help!

 

[berkeman]

I'll try to make my description quick so you don't tldr me.
So I worked on this project in school on a 6.5inch woofer.
I took it from an old computer set (creative) and the amp was dead.
I designed and built a new dual supply class ab stage amplifier with a low pass filter.

So now I don't have a supply, but want to use it for a home theater or computer set up, but passive sucks so I want to design a new single supply amp.

What's the best configuration, and the best IC's to use for this, and can I implement single-supply with a class ab output stage?

All I can ever find on the web is dual supply for gainclones in car audio, but I'm not using it for my car.
Thanks for the help!

Welcome to the PF.

What's a "tldr"?

How would an audio power amp for a car be dual supply? Car power supplies are 12V and GND, I would think?

National Semiconductor has a series of audio amplifier ICs, but I haven't used them for several years.

 

[Mcfloyd]

I think I figured it all out, I'm going to buy a kit from parts express.

 

[berkeman]

I think I figured it all out, I'm going to buy a kit from parts express.

Great, sounds good.

And to tie off the thread with the help of www.acronymfinder.com

TLDR -- Too Long; Don't Read (aka Too Long; Didn't Read)

 

[Averagesupernova]

Berkeman, car audio amps have switchers that generate + and - supplies. How else would you get several hundred watts out of a 12 volt source with a 4 ohm speaker?

 

[Studiot]

This site has a good run down of modern alternator supply capacity.

http://www.k0bg.com/alternator.html

A rule of thumb for linear power amps is

$$Power = \frac{{{V^2}}}{{8R}}$$

Where the 'power' describes the max available RMS power, V is the voltage between the rails and R is the nominal speaker impedance.

For a 12 volt supply this works out at 4.5 watts RMS. Actually slightly less as you can never get it all.

With what is these days called an H bridge configuration that effectively switches the rails polarity every half cycle you can multiply this figure by 4 ie 18 watts.

To go beyond that, yes some form of rail converter must be employed.

 

[berkeman]

Berkeman, car audio amps have switchers that generate + and - supplies. How else would you get several hundred watts out of a 12 volt source with a 4 ohm speaker?

Ah, thanks ASN. I was confused by his response.