Power supplies connected to motor controllers can be shielded from voltage spikes by this shunt regulator. The lower-power version features twelve SMT shunt resistors populated on one side of the PCB, a fixed set point of 26.4 V, and a shunt resistance of 4.00 ohms. The set voltage can also be altered by adding an external potentiometer. The majority of motor controllers deal with situations where motor energy is returned to the power source, usually when the motor is slowing down. Usually, that power source is a battery that can withstand the current that is fed into it. The reverse current can be a useful "regenerative braking" feature that prolongs the battery's overall life. For programs that don't