1. The document describes simulations of a PID controller and motor equivalent circuit model. It shows the PID control formula and simulations of a PID controller circuit using that formula.
2. The simulations show the error value in red and output value in blue. The output increases over time to reach the setpoint, while the error decreases.
3. A second simulation is shown using the same PID control formula but with a different circuit. This output also increases to follow the setpoint, while the error decreases as the system approaches the setpoint.