This unit takes inputs from proximity switch. User can set the Speed, start- up delay, trip-off delay, Hysteresis and Teeth ratio, from the front panel keys. The input pulses from the proximity switch are converted to RPM. This RPM is compared with the set value and a relay is operated if the speed is lower or greater than the set speed even after the start-up delay is elapsed and the low speed condition persists for a time more than the trip-off delay. The unit is calibrated to operate between 60 rpm to 9999 rpm. The unit operates at a wide voltage range from 10Vdc to 30Vdc and consumes ultra low current of just 30mA.