Operational Amplifier (Op Amp) - More Complex Opamp Circuit - Classic Integrator Circuit using a ,01 capacitor, 20k resistor and an opamp

At the feedback from the output to the inverting input resides a .01 uF capacitor. The inverting input will have a square wave that is rise above and fall below 5 volts where 5 volts is at the midpoint of the square wave. When the square wave is abov ethe 5 volts, there will be current from the 5 volts, but not into the inverting input. The current goes to the capacitor. There will be a linear voltage change at the capacitor when current is applied to the capacitor. The voltage ramps down. When the voltage is below the 5 volts, the current will be going in the other direction and the voltage will ramp up. The end result is creating a triangle wave from a square wave.