Design an audio power amplifier

[davenn]

Is there a way to know the output?

audio wattmeter
oscilloscope
measure the voltage across a known load resistor ( 8 Ohm)Dave

 

[meBigGuy]

Is there a way to know the output?

Depends on how accurate you need to be, what response you require, etc. Not sure what your goal is.

For example, you could build a true RMS detector with a threshold comparator and an LED, or add a VU meter, or just detect high output peaks, or whatever.

 

[PhysicoRaj]

Thanks! I downloaded a 1kHz sine beep. I'll play it in a loop and check the rms across the load. Then I hope I can work out the gain etc.

 

[meBigGuy]

LOL --- ok, you were just trying to get the gain aprox. correct. I thought you wanted continuous monitoring for some reason.

 

[PhysicoRaj]

:D well it'd be nice if I had some continuous monitoring, but the only thing I have (and could afford to) is a DMM.
It's enough because I just want to know when the amp is at min/max/optimum, so that I can hook up the speakers at the correct operating point.

 

[davenn]

I just want to know when the amp is at min/max/optimum, so that I can hook up the speakers at the correct operating point.

that sounds a really strange statement

Dave

 

[PhysicoRaj]

that sounds a really strange statement

Dave

I'm not sure if the amp is going to blindly deliver 8w to 8ohms it's a function of input voltage. So to check the limit I'll have to vary both the input (volume control) and the gain, check the output on an 8 Ohm load {not sacrificing my speakers, maybe another old speaker ;)} get it to around 6w undistorted, then connect the speakers. That's what I meant.