- Joined Nov 11, 2014
this is a complimentary oscillator. look at point 2,which is base of Q2,assume there is positive voltage noise signal,then point 3will go down. then through C1,point 4will go down, then Q1 current through emitter to collector will go up, this makes point2go up, so this is a positive feedback, so it is also a positive feedback.
conversly,if point 2has a negative voltage noise, it can have a negative voltage feedback,which means a positive feedback.
so the question comes:what will be choosed to determine voltage point 2,so of point3,C1 right hand?