modified 5 years ago

PreAmp bjt feedback network super 555

01:18:50

Preamplificador de dos transistores bjt realimentado negativamente de ganancia -10. Puse 555 sólo para llamar la atención.

published 5 years ago

fatcat2

5 years ago

Is this voltage series feedback?

MatthewKessler

5 years ago

I cannot understand a word you're saying. But this circuit is cool.

JoeHH

5 years ago

Thanks!

fatcat2

5 years ago

@JoeHH, I had previously encountered such a circuit but I didn't know what feedback it uses. B=R1/R2 here and not the usual formula; Idk why. What kind of feedback is it?

JoeHH

5 years ago

in effect, the feedback loop determines the gain, but only if it is taken into account that the input of the amplifier is at the base of the first transistor. plus there's the input resistor.

fatcat2

5 years ago

The CC stage's output is fed back to the CE stage so that the output closely matches the input. I suppose that it is current series feedback.

fatcat2

5 years ago

Av/(1+BAv) helps. B=R1/R2 I think.

JoeHH

5 years ago

Right... B=(hie//10//124//223)/(hie//10//124//223+223) /Av/=betha*(2//(betha+1)*4.7)/hie Vin=100mV*(hie//124//223)/(hie//124//223+10)

JoeHH

5 years ago

now yes, let's get to work... Vout=Vin*Av/(1+BAv)

add comment in editor

EveryCircuit is an easy to use, highly interactive circuit simulator and schematic capture tool. Real-time circuit simulation, interactivity, and dynamic visualization make it a must have application for professionals and academia. EveryCircuit user community has collaboratively created the largest searchable library of circuit designs. EveryCircuit app runs online in popular browsers and on mobile phones and tablets, enabling you to capture design ideas and learn electronics on the go.