Regenerative Braking with Capacitors
Thus far, we have built a basic circuit to demonstrate the different regimes involved in regenerative braking. The behavior of the circuit is dependent on the way the three binary slide switches are turned. A schematic of the circuit is shown above.
Components:
- Two 9V batteries
- Fixed Positive Linear Voltage Regulator
- Three binary slide switches
- 16V, 1500uF Capacitor
- 24V DC Motor
Initial Circuit:
The image on the above left shows one possible path of the circuit. When the switches are aligned this way, the batteries are used to power the motor, which simulates the motion of a vehicle when power is being used to drive the vehicle forward. 18V enter the fixed positive linear voltage regulator, which regulates this voltage to 12V. This is then used to drive the motor.
Another possible regime of the circuit is highlighted by the circuit to the top right, where the batteries are cut out from the circuit. In this orientation, the pre-charged capacitor, which is connected to ground and to the motor, can be used to drive the motor.
In the final orientation, shown above, regenerative braking occurs. The battery is cut off from the circuit, and the positive port of the battery is connected to the motor while the negative is unconnected. For this circuit, manual spinning of the motor can be used to charge up the capacitor.