I checked ESP works they all used IC were just allowed to use transistors

 

Could you find me alternative circuit on net that works well?

hi ganny,
I would like to help, please give me an idea of your specification and I will discuss it with you.

Regarding the results in LTSpice, I have been using LTS for over 10 years, running many circuits using the 2N2222.
All have worked in practical circuits giving results close to the simulation, so I have a high degree of confidence the the 2N2222 model.

I have no experience of Proteus
Eric

 

Hello,

Then have a look at this book:
https://archive.org/details/fe_Audio_Electronics_Transistor_Amplifiers_Design_Handbook_D._Self

Bertus

 

I have no experience of Proteus

Proteus works very well The circuit I have drawn and the one you have drawn seem to work as expected.

The 2n2222 model within Proteus is flawed.. The 2n2222a works as it should.. I expect the circuit being simulated by Granny isn't quite correct.. I can't see the connections in this pictures properly..

 

Hi guys, Could you find me an audio amplifier made using transistor about 4W? I spent a lot for this project yet I have done nothing. Its hard to look for components. Make sure it is easy to look at stores around. Thank You

 

Your only criteria is use transistors and build a 4 W amplifier? No criteria on the input signal?

No criteria on the total harmonic distortion?

 

Hallo,

As you posted in homework help, are you not supposed to design an audio amplifier?
What you are asking is like making a copy of a given design and not your own design.
The book I posted in post #23 will give you good guidelines for designing an amplifier.

Bertus

 

No criteria on the total distortion and even in the output signal. Yes its just a copy from internet it doesnt require own design

 

Also I have limited time to study all those things

 

hi g,
Anyone of these look interesting.
https://www.google.co.uk/search?q=a...frutLZAhWCKVAKHe3TAEUQsAQIJg&biw=1176&bih=610


@bertus
EDIT: Agreed ref your link.

 

Hello,

@ericgibbs , This would be a better query, as the TS is supposed to use transistors:
https://www.google.co.uk/search?cli......0...1c.1.64.psy-ab..0.0.0....0.LySTlhLkgpU

Bertus

 

If there is no criteria, then what you have originally is good to go.

 

I made a prototype of the audio amplifier using 4W/8Ohms speaker it didnt works

 

hi ganny,
Do not get disheartened, we have all been in that position.
Post the circuit diagram of this latest amp.
E

 

You would have to design an amplifier to be capable of driving a 4W speaker. I'd say build a 2 or 3W amp.

Being it's an audio amp, you would want low distortion so the music or voice would be clear.

 

I saw this in my book Electronics devices by Floyd. What transistor should I use in this circuit so ot will work in 4 watts 8 ohms speaker. Pleaseee help me.

 

hi ganny,
That is a poor example, you will not get 4Watts from that output driver, possibly 2-300mW.
E

 

Hello,

Perhaps you could have a look at the attached PDF with a 3 Watt amplifier.

Bertus

 

Hi,

One of the big drawbacks to the original circuit was that it has only a 5v power supply.
That's not going to produce much power out. At most, and this is beyond what is really possible, if we divide that by 2 we get 2.5v and 2.5v and 8 ohms doesnt lead to much power. It's actually much less than that though because of transistor drops and resistor drops, etc., as well as a DC voltage to sine voltage conversion factor like around 70 percent or so. So the theoretical limit of output power is very low, typical maybe for headphones. For example, with a 12v supply and plus and minus 5.5v output zeroed at +6v, the factor is 0.71 or close to that.

 

I understand. Thanks for your response