chyun84 said:
hmm.....thanks for replying.
i'm currently working on this circuit and need to write report for the circuits but i lack of knowledge. so i hope someone can help me over it. what i need now is:
what theory should i used on that circuit?
and what formula or equation should i use?
since it is hard to calculate the gain, i think i will put in those formula inside my report only, but i hope someone can help me with the question above. thanks
++++++++++++++++
the gain of Q1 can be approximated
R2 =5k
Ic estimated for Vcc =6vdc , IcR2 =3vdc, Vce =3vdc
Ic = 3v/5k =0.6 ma
Ace1 ~ x60
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calculations
Ib = (3 -Vbe)/100k = 0.024ma
Ie = 0.624ma
* transistor re_1 = 26mv/Ie = 26/0.624 = 42 ohm
*this is key to understanding bipolar transistors
that do not use external emitter resistors
gain common emitter say hfe_Q2 =x50
Ace1 ~ (R2 || hfe_Q2*r6 )/re1
calculate the rest yourself.
of course here are many assumptions :
Vce, Ace simplified, hfe1,2;
R4||C2 feedback ignored due to say 600 ohm generator impedance.
hawk2eye