The schematic sourced from evilmadscientist.com
This is how the internal of 555 timer works. You can change the value to figure out what is going on.
To start the oscillation set the voltage from 5V to 9V. The simulation can not be start with high voltage or resulting the simulation cannot find solution (EveryCircuitSimulatorProblem). Enjoy.
Blue is output state (Output Pin).
Green is capacitor charging (Trigger & Threshold Pin).
Orange is capacitor discharge (Discharge Pin).
I have updated the circuit from a 66-33% duty cycle (66% High 33% Low) to a 50-50% duty cycle (50% High 50% Low).
