http://imageshack.us/photo/my-images/823/withdcsource.jpg/

i have designed a simple circuit with a dc source,i wanted IC to be 18ma, that is great cause i have it here.but when i tried to keep a ac source,i am getting trouble,is there any mistake i done ? please help me

http://imageshack.us/photo/my-images/585/acsignal.jpg/

 

Hello kdg007,

The reason Ic is not 18 mA is because you do not have any base-bias current. If you wire a resistor to the base such that Ic/beta flows down through the base and add the AC source and capacitor before that, you will have better luck!