questions on Class B audio amplifier

Look at using a LM1875 Ic amp, that chip starts at 16 Vcc up to 60 Vcc.

if you drive it with a complementary supply, then it's 8..30 Vcc/Vee etc.. This chip does 20 Watts and can source/sink 4 Amps. that's enough to drive some heavy complementary trannies.

"

Why do you waste your time like this ?

Please become an adult.

Graham

** Nope - it is actually much less. ** Not a snowflake's chance in hell. ** No to both.

** Not when delivering any power into a load.

** It is a complementary BJT follower /current booster tacked onto the output of an op-amp.

Good of a couple of watts of lo-fi.

You are UTTERLY clueless.

..... Phil

--
Same old shit, eh, Graham?

The guy is obviously having some difficulty wrapping his head around a
problem and isn\'t afraid to admit it, and instead of giving him a
helping hand, you give him a slap.

What a really mean bastard you are.

JF

Always show your assumptions.

You're assuming you can get 24V p-p out of that circuit -- review the base-emitter drop of a transistor, and the voltage drop of the op-amp before you make any promises.

See my comment above. Yes, but (but this is not the way to achieve that!!!)

Read the web page. If you have an oscilloscope to measure output -- try it. If you don't, try it out on LTSpice (which is free). Use their "generic 1-pole op-amp" with a GBW to equal the TL082, and try it at different frequencies.

In theory, yes, in practice -- what's your operating point? What class AB amp are you comparing it to? What frequency signal are you pumping through?

Yes, but a typical power amp sounds better....

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" gives you just what it says.
See details at http://www.wescottdesign.com/actfes/actfes.html

Yes but it sounds shit.

Graham

Nothing compared to you.

And Universities are turning out kids even stupider than this !

Graham

--
You calculated it right, but the TL082 isn\'t a rail-to-rail output
opamp, so the output into the emitter follower pair would be
considerably less than 12V resulting in, consequently, less than 18
watts CW into the four ohm load.

"John Fields"

** Lets see what it *really* is then:

From the data on the TL082, with +/-12 volt rails and say 500 ohms load, the available output swing is +/- 7 volts.

Equates to 14mA peak.

From the data on the TIP41, Hfe = 50typ at Ic=1A & Vce= 4 volts.

50 times 15 = 700mA.

700 mA into 4 ohms = 2.8 volts peak.

Or 1 watt, rms continuos.

Long, long way from 18 .........

...... Phil

--
So, you admit you\'ve met your master?

For years now, in an effort to try to communicate honestly, I\'ve tried
being kind to you, and cordial, and courteous, and objective, and
logical, and even friendly, but it seems that\'s all come to naught since
all you\'re interested in is denigrating anyone who brushes up against
your holy space and questions your opinions.

JF

--
RMS? ;)

JF

Ah, numbers... goodie...

Where did you get 500 ohms for load?

Yep...

Thanks,

Michael

** See above.

You just described yourself beautitfully.

Graham

It's a total heap of garbage. It's almost beyond a joke. If the rest of the site is like that then try to forget anything you 'learnt' there.

Graham

--
Why, thank you Graham!

And how do you think I described you?

Beau_tit_fully as well?

Freudian slip: When you say one thing but mean your mother.


JF

--
My, my...

A blanket condemnation, but nothing to back it up with?

How typical of you!

 
JF

--
Yup.

Nicely done. Thanks! :-)
JF