Common Emitter amplifier

<< https://www.circuitlab.com/circuit/sc7834/test1/ >>

this amp. ckt is not amplifying, moreover the output is attenuated and distorted,,

where theoretically it must be -5 times hte input..

any justification please ..

and thanks in advance..

by QDichter
February 26, 2013

Your link is broken.

by signality
February 26, 2013

signality i think it worked with me.. try again please ,,

by QDichter
February 27, 2013

Working Vbe of a bjt is about 0.55V. With a 1V supply your base is biased to about 0.18V.

Your transistor is almost turned off. The only thing that turns it on are the peaks of the 20V pk-pk signal input which are in turn loosely clamped to about 2.5V peak at the base of Q1.

1) Reduce the input voltage swing (V1=1V);

2) Increase the supply voltage (V2=10V).

:)

by signality
February 28, 2013

ok signality,, i'm so embarrassed ,, my mistakes look like a junior ones,,,

anyway thank you very much for replying to me...

now i can see that the output is amplified ... by approx. -5 times the input besides a D.C. offset according to the biasing voltage ...

thnx again ..

regards ,,, Q .

by QDichter
February 28, 2013

Deep joy ...

by signality
February 28, 2013

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