The KBWS PWM Series of DC Drives contain a fully isolated input and are designed to operate PWM and SCR rated Permanent Magnet motors. They provide high motor efficiency with quiet motor operation. The KBWS uses pulse-by-pulse current sensing to protect the SCR power bridge against shorts due to commutator arcing and prevents motor demagnetization. The controls contain an AC line inrush current limiter (ICL) which reduces AC line surge currents during startup. This drive requires a Plug-in Horsepower Resistor®* to operate. A 5k ohm potentiometer is included.