good day everyone. can plss someone help me to calculate this circuit.

Ian0

Joined Aug 7, 2020
10,276
Do you know how the circuit works?
Do you know which two resistors set the gain?
Do you realise that the power efficiency will depend on the shape of the output waveform?
 

Thread Starter

agentperry15

Joined May 19, 2023
35
Do you know how the circuit works?
Do you know which two resistors set the gain?
Do you realise that the power efficiency will depend on the shape of the output waveform?
Honestly sir I don't know how but what I know is that this is a audio amplifier and the RV1 and RV2 is one that control the volume or gain.
 

RoofSheep

Joined Mar 7, 2023
36
Do you know how the circuit works?
Do you know which two resistors set the gain?
Do you realise that the power efficiency will depend on the shape of the output waveform?
In my opinion you would need a lot more knowledge to analyze this circuit in detail.
 

Ian0

Joined Aug 7, 2020
10,276
RV2 would set the volume (not the gain) but only if it were wired correctly. The capacitor is in the wrong place.
You can think of it as an op-amp, with the non-inverting input at the base of Q1 and the inverting input at its emitter.
That should get you a approximate value for the gain.
To get an accurate value, and a value for output impedance, you are going to need the open-loop gain, and calculating that is not trivial (I'd just use SPICE).
Not only do I agree with @RoofSheep , but I think the question is impossible to answer with the information given.
 

Thread Starter

agentperry15

Joined May 19, 2023
35
RV2 would set the volume (not the gain) but only if it were wired correctly. The capacitor is in the wrong place.
You can think of it as an op-amp, with the non-inverting input at the base of Q1 and the inverting input at its emitter.
That should get you a approximate value for the gain.
To get an accurate value, and a value for output impedance, you are going to need the open-loop gain, and calculating that is not trivial (I'd just use SPICE).
Not only do I agree with @RoofSheep , but I think the question is impossible to answer with the information given.
I tried to simulate this circuit in proteus and the gain that I get is 30 db. my problem now is that how to calculate it theoretically. i tried to used 60 volts as its input and 0.138 as its output. i use the formula Gain=Vout/Vin and all I get is not close to the simulated value. i don't know what I did wrong. what should I do sir ?
 

Ian0

Joined Aug 7, 2020
10,276
You need to correct C3. It should be between the wiper of RV2 and the base of Q1. Connect the input signal directly to RV2.
 
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