Dc motor controller is used to implement the motor controller can direct current (dc) and mechanical energy conversion from each other. Then the no-load current of how to control it? Below small make up for it. 1. Due to the working efficiency of the dc motor controller = (Rated power -No-load current no-load voltage)/ rated power, of which the 'x' no-load voltage idle current is no-load loss, therefore whether no-load current is too high or too big, will lead to reduce the motor controller life. 2. Check between rotor and stator, see if there is a sweep of phenomenon. 3. By adjusting the position of the brush, after electrify positive &negative error between narrow. 4. Controller of dc motor bearing to check in time, ensure the normal use of the bearing. 5. The bearing to add grease on a regular basis to ensure the lubrication effect. Through the above methods, can effectively control the no-load current of dc motor controller, and improve efficiency.