Descripción de One transistor and RC filter.mov:

Simple amplifier basics with emphasis on hfe the IC/IB factor and that it is not set in stone as we are mislead to believe, but can for example in the BC548 range from 125 to 900. For the RC high pass filter i used 10 nf and 2.7k ohm equation is 1/ (2*pi*R*C) and the breaking frequency around 5.8 Khz Thus we can choose the hfe we need and design from there. Go here and learn how; Then you will be able to see how an R1 = 570K vs 100K, and an R2=125K vs 27K will allow this little amplifier to work just as well as i RE-TESTED with the new values after re-designing for the new R2 "AND CHOOSING MY OWN HFE OF 299.3 " many other "ratios" of R1/R2 will also work .... http://www.rason.org/Projects/bipolamp/bipolamp.htm Therefore HFE is not set in stone but can be chosen by the designer as long as he stays withing the transistors maximum hfe rating_ Some of this extra information comes from the American Radio Relay League .of which i am KD4VAF (expired) the assumed hfe=100 error was based on assumption not having gotten to that point in my analysis; however, the actual voltage gain is about 4.0... roughly RC/RE Also i did not design this one but analyzed it I GIVE CREDIT for the actual design to; http://www.zen22142.zen.co.uk/Analysis/colfr.htm