SmartFan Aurora for speed control of dc motors accepts analog control signals (0ā5 V, 0ā10 V, 0ā20 mA, potentiometer) and adjusts voltage to the motor from 0 to 100% output voltage using a buck control circuit that operates at high frequency. It operates from 12ā48 Vac or 10ā72 Vdc power source to control 12, 24 or 48 Vdc motors with a current rating up to 6 A.