So I want to start off saying that I'm a senior in college in Electrical Engineering and I've been learning a lot about various kinds of circuits involving oscillators and I would like to know more about them. In school we talk a lot about them in various circuits and how important they are to those circuits but we haven't really learned anywhere how a simple oscillator works outside of ideal conditions for an LC circuit. But since those don't exist in real life you have to be clever and invent a way to make something oscillate. And from my research most of the oscillators today use transistors in various combinations with capacitors and resistors (OpAmps, 555 timer, etc). I have an old radioshack lab book that works you through various electronic "projects" to help you understand circuits and I remembered it had an oscillator example, so I decided to open it up and try it out, and maybe that would help me understand it better. Even after reading the authors note and drawing up a circuit diagram myself, and changing the layout of the circuit so maybe I could understand it better, I'm still confused about how its oscillating. If someone could explain it to me in detail step by step how its oscillating I would be greatly appreciative as this is something that has been bothering me for some time now. I want to have a fundamental grasp of how a basic oscillator would work. So I figured I would present my question to the awesome guys here at PF who explain things so well. I attached the picture of the circuit with the authors explanation of whats happening. What bothers me is how the capacitor and the PNP transistor operates in this circuit. The capacitor is constantly being charged, so how could it discharge through Q1? Wouldnt it just discharge while charging? So nothing would happen and that whole part of the circuit would just stay an open circuit after the capacitor has charged fully. Also the PNP transistor....I must not have a good grasp of how PNP transistors work because I would think the PNP transistor would always be on (current flowing from emitter to collector) and then when current is applied to the base it would turn off. Although I know from my electronics class you don't necessarily have to apply current through collector-emmitter so it does depend on how the configuration is setup. In this circuit they claim that once the NPN "turns on" when the base has current flown through it then current flows through emitter-collector of the PNP. That to me suggests current is flowing from NPN through base-collector through to the base-collector of the PNP. But then wouldnt that mean the NPN is off? Any help in understanding this would be greatly appreciated. Thanks in advance PF guys!