IC Spares is a stocking supplier of VFDs for low-voltage and medium-voltage applications. IC Spares has VFDs for purchase and rental for depending on the end-user needs. A Variable Frequency Drive (VFD), also known as an adjustable frequency drive, variable speed drive, or inverter, is a motor controller that regulates an electric motor by adjusting the frequency and voltage of its power supply. During motor start-up or stop, the VFD can control the ramp-up and ramp-down of the motor.