IC 555 in the adjacent figure is configured as an Astable multi-vibrator. It is enabled to oscillate at t=0 by applying a high input to pin 4. The pin description is: 1 and 8 − supply: 2-trigger; 4-reset; 6-threshold; 7-discharge. The waveform appearing across the capacitor starting from t=0, as observed on a storage CRO is

The circuit of Figure shows a 555 Timer IC connected as an Astable multi-vibrator. The value of the capacitor C is 10nF. The values of the resistors  and  for a frequency of 10kHz and a duty cycle of 0.75 for the output voltage waveform are

The type of power amplifier which exhibits crossover distortion in its output is