Hoping someone can help me with some basic questions about resistor-capacitor oscillator (timer) circuits. I can put them together, I see them working, but I don't understand why! In the circuit in the attached drawing, if one installs the correct values of resistor and capacitor, I know that the transistor should repeatedly switch on and off as the capacitor repeatedly charges up then discharges through the base-emitter junction. But what I don't understand are the following: - At time=0, I understand that voltage and current flow right through the un-charged capacitor. But I do not understand why voltage/current do not instantly also flow right through the base-emitter junction of the transistor, switching it on -- after all, the base-emitter junction is basically just wired in parallel with the capacitor, no? Does the base-emitter junction have a very high resistance or something? - Why does a resistor-capacitor circuit oscillate at all, as opposed to reaching an equilibrium in which the battery and the capacitor both discharge to ground simultaneously via the base-emitter junction of the transistor, with the battery constantly keeping the capacitor at some charge level? - Why does the capacitor take a while to charge up to the voltage at which it "opens" the base-emitter junction then, when it reaches that voltage, completely empty itself through this junction as opposed to just bringing itself back down to just below the "transistor switch-on" voltage? Does the base-emitter junction take a while to turn itself off or something?