#### apollo321j

Joined Dec 30, 2020
4
Hi I have a problem about Transformer coupled Amp.

I did this but there is no gain in output I see that what is Vinput Could you help me thank you .What is wrong in this circuit I am a student and new in this topic .

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#### MrChips

Joined Oct 2, 2009
22,467
Welcome to AAC!

Do one stage at a time.
In the first stage you have VE = 10V from a 12V supply. This is more like a class-C amplifier than a class-A amplifier.
R1 = 36Ω putting the input impedance to less than 36Ω.

#### apollo321j

Joined Dec 30, 2020
4
Welcome to AAC!

Do one stage at a time.
In the first stage you have VE = 10V from a 12V supply. This is more like a class-C amplifier than a class-A amplifier.
R1 = 36Ω putting the input impedance to less than 36Ω.
Thank you I will try what you say .I must design it so I put it to circuit my teacher say your resistors too small what do you think about it .

#### djsfantasi

Joined Apr 11, 2010
7,187
Thank you I will try what you say .I must design it so I put it to circuit my teacher say your resistors too small what do you think about it .
So if you must design it for homework, what do you think about the size of your resistors?

#### apollo321j

Joined Dec 30, 2020
4
So if you must design it for homework, what do you think about the size of your resistors?
Sory sir I attached wrong files my values are like on this photo I realized wrong resistor but I can't change them .

#### MrChips

Joined Oct 2, 2009
22,467
Why is RE = 1kΩ?

You want VE to be a fraction of 12V, say around 1-2V.
You want the input impedance to be high, 5k-50k range.

#### apollo321j

Joined Dec 30, 2020
4
Why is RE = 1kΩ?

You want VE to be a fraction of 12V, say around 1-2V.
You want the input impedance to be high, 5k-50k range.
There is no reason I assume it I want to 10 gain from first stage and I started by assuming Re=1 k \Omega and Ie = 10mA