Hello,

I'm having trouble getting the right output graph for the following circuit (class-b amplifier w/ darlington pair).

The correct output is supposed to be a nice sin wave with some distortion (the problems objective is to show it to you visually)... but I'm not getting the right plot. I've attached my results also.

I'm not sure where my slip-up is -- I've checked everything so I'm assuming that it's something very minor and involves PSPICE (I'm still getting accustomed to it).

Can anybody help me out? I'd REALLY appreciate it. Thank you for your time.

--
Best Regards,
Arthur

 

I got the following error when I put the circuit in exactly as shown:

Expecting keyword STIMULUS, saw V.|

STIMULUS has to do with the configuation files so...crap.

 

You need a base bias resistor from the bases of Q1 and Q3 to GND.

 

The dreaded input bias return path.

 

The bias resistor fixed it. Neat, although, the value of my bias resistor seems to have tuned some loss to the circuit.

 

So it's not supposed to be a sin wave?

I'm still getting a transient looking wave, like a capacitor type output, and not a sin wave which I thought was the correct output.

Thanks for your replies!

 

Check your print step rate. I didn't really zoom in on the output. It "kind of" looked sinusoidal. But it wasn't a smooth wave by any means.

 

You are suppose to see a crossover distortion during each half cycle. The answer to why this occurs and how to solve that problem will appear on later tests.

 

Okay! Thanks I got it to work... I just overlooked zooming it out >_>

But thank you everybody