I need to know if my formula's are correct for current gain. Sorry for shitty drawing.
I know beta would change the dc values slightly but for my prof. it's close enough.

Beta AC = 70.


DC Analysis
VB = R1R2/R1+R2
VE = VB - VBE
IE = VE/RE

AC Analysis
r'e = 25mv/IE
Req = R1 || R2
Rout = RC || RL

Voltage Gain
Av = Rout/ r'e
Vout = Av * Vin

Current Gain
Ai = Iout/Iin
Iin= Vin/Rin(total)
Rin(total) = Req || Beta AC(Rin(base))
Rin(base) = Beta AC * r'e
Iout = Ic + Il
Ic = Beta AC * Iin
Il = Vout/ RL


Bolded is what I am unsure off.
I know current out is the combination of current through the collector resistor and the load resistor since AC see's DC source as a ground. So, does that mean the current in multiplied by beta is equal to the current through the collector?

This post was edited by ROM on Apr 2 2015 11:04am

My mistake on the formula for VB in the DC analysis, I know its a voltage divider. I mistyped it.

This is what I came up with.
If your R1//R2 is a large value then you can assume the your Ib is approximatly equal to your Iin. And then therefore Ic is approximatly = Bac * Iin
Heres a photo of what I came up with.

Fg maybe?

/e if your prof is Gandam PM me. It looks like one of his questions lel.

This post was edited by marioo1182 on Apr 6 2015 12:04am

Thanks. Heres some fg for your trouble. It helped.
Can you tell me where I would modify my formula if you were to include a resistor after the source?

Your formula for which?
Your Ic = Iin*Bac would still be correct because the current after the resistor would approximatly be the same as the current through Ib because R1//R2 is so large.