Audio Amplifier Using TIP 147, 142

[Usama Khurram]

<< Obnoxious all caps post fixed by Moderators >>[/color]
I have made an audio amplifier using an LM386 IC, but it does not amplify any sound from the microphone. Please help me to improve this using a Darlington pair or any other power transistor like the TIP147/142...

 

[davenn]

Please don't use uppercase lettering ... its considered shouting when typing online

OK you haven't given us enough info to help you
how about circuit diagram if what you have built and maybe a photo or 2 of your construction so that the wiring can be checked for errorsDave

 

[Jeff Rosenbury]

Also, please add any information you have about your microphone.

 

[Usama Khurram]

I have cascaded these two , means first i install the Common colletor because of high input impedence and then i apply its output from emitter to LM386 ... but theere is no sound which i applied on common collector base. which type of microphone should i use for this.. please guide me.

 

[Svein]

first i install the Common colletor because of high input impedence and then i apply its output from emitter to LM386

Well, the common collector stage you have shown is just a textbook drawing. What does your real circuit look like?

 

[Usama Khurram]

Well, the common collector stage you have shown is just a textbook drawing. What does your real circuit look like?

output speaker specs is: 4Ohm, 3 Watt

 

[NascentOxygen]

Your common-collector stage needs fixing! You'll almost certainly need a capacitor to couple the signal from the mic to the base, and this capacitor needs to go directly to the base (you are showing the mic wrongly connected directly to the power rail, V_cc).

 

[Usama Khurram]

can

Your common-collector stage needs fixing! You'll almost certainly need a capacitor to couple the signal from the mic to the base, and this capacitor needs to go directly to the base (you are showing the mic wrongly connected directly to the power rail, V_cc).

you please draw the picture on peper and send me here? as it does not work till now.

 

[Svein]

you please draw the picture on peper and send me here? as it does not work till now.

Here is a schematic for a "common collector" stage.