Some users in the use of DC motor, to achieve his positive and negative has not been very clear, do not know how to control. In fact, through the following two methods can be achieved DC motor positive and negative.
First, the armature reverse connection method: that is to maintain the excitation voltage of the terminal winding polarity unchanged, by changing the DC motor armature winding terminal voltage polarity to reverse;
Second, the excitation winding reverse method: that is to maintain the armature winding terminal voltage polarity unchanged, by changing the polarity of the excitation winding terminal voltage to the DC motor. When the voltage polarity of both changes at the same time, the direction of rotation does not change.
He and the excitation and DC motor generally use the armature reverse connection method to achieve positive and negative, should not use the excitation winding reverse method to achieve positive and negative reason is because the excitation winding turns more inductance. When the field windings are reversed, a large induced electromotive force is generated in the field windings, which can damage the insulator and field windings.
Induction DC motor should be used to reverse the excitation winding reverse direction, because the series DC motor armature voltage higher at both ends, and the excitation voltage at both ends of the coil is very low, easy to reverse, motor vehicles often use this method The
After reading the above two methods you learned it, if you are also troubled by this problem, it may be based on the type of DC motor number to take a look at the above