The “Victor” is an electric motor speed controller. It is used to vary the speed of an electric motor in a smooth progression anywhere from full forward to off(neutral) to full reverse.
You connect your battery to one side of the Victor, and your motor to the other side. Then, using PWM signals plugged into the input you can control the speed and direction of the motor.
The most common source for the PWM control signal is an Innovation First Robot Controller (Full-size or Mini). You can also control a Victor using standard hobby radio-control (R/C) equipment. Use a PWM Signal Driver with a Victor when you are not using an IFI control system.