So, i am doing P3A for college work, and i need to do calculations. I did DC calculations, now i started AC and already i have a problem.

This is a scheme ---> 60-80W Power Amplifier

Generator source voltage is 100 mV (70.7 mV RMS) with frequency 1 kHz

I am simulating project in Isis proteus so i`ll put some pictures so you can see where my problem is.

First picture is understandable, voltage across input filter is 70.7 mV and there is no problems.

But, when i put only a resistor in parallel how it is in project scheme, i dont know what is happening anymore. (second picture)

I am all confused when i put capacitor in parallel with resistor like in third picture.

I was trying with impedance calculations and many other things but never got same results like in simulator. So, if somebody of you guys understand this please give me an answer or just a path to follow

thank you very much

This is a scheme ---> 60-80W Power Amplifier

Generator source voltage is 100 mV (70.7 mV RMS) with frequency 1 kHz

I am simulating project in Isis proteus so i`ll put some pictures so you can see where my problem is.

First picture is understandable, voltage across input filter is 70.7 mV and there is no problems.

But, when i put only a resistor in parallel how it is in project scheme, i dont know what is happening anymore. (second picture)

I am all confused when i put capacitor in parallel with resistor like in third picture.

I was trying with impedance calculations and many other things but never got same results like in simulator. So, if somebody of you guys understand this please give me an answer or just a path to follow

thank you very much