555 Timer Circuit
Many of us will have seen a 555 astable oscillator working, but how many of us have seen one actually start up?.

SpiceAge suggests that the first cycle will be longer than all the others because C1 starts with zero charge, whereas on all subsequent cycles it starts at 1/3 of the supply voltage. The green trace shows the voltage on C1, whilst the red trace is the voltage at the discharge pin (when it drops low, C1 discharges through R2).