Stepper motor stepper motor according to the motor structure is divided into three kinds: permanent magnet (PM), equation (VR)And hybrid (HB)。 Permanent magnet stepping, generally for two phase, torque and volume is small, step Angle is commonly 7. 5 or 15 degrees; Eighty percent for cheap consumer products. Reactive step for three-phase commonly, can achieve high torque output, stepper Angle generally to 1. 5 degrees, but the noise and vibration are very big. In Europe and the United States and other developed countries have been eliminated in the 80 s; In jewels step refers to a mixture of permanent magnet and the advantages of reactive. It is divided into two phase, three-phase and five phase: two phase step from the Angle of the general is 1. Step 8 degrees, three phase from the Angle of 0. Step 9 degrees, and the five phase from the Angle of general to 0. 72 degrees. In jewels step is the most common industrial motion control using the motor. In addition, in accordance with the motor driven architecture and can be divided into the single polarity (unipolar)And bipolar (bipolar)Stepper motor. Single polarity driving circuit using four transistors to drive stepping motor phase, the two groups of motor structure is shown in figure 1 contains two sets of coil with a center tap, the whole machine six lines to connect with the outside world. This kind of motor is sometimes referred to as the four phase, but this simple call a hybrid is not correct, because it is in fact only two phase, accurately should be double phase six line type stepping motor. 6 line type stepping motor is also known as single polar stepper motor, actually can use single or double polarity polarity together drive circuit. Figure 1: a single polar stepper motor drive circuit of bipolar stepper motor drive circuit is shown in figure 2, it will use the eight transistors phase to drive the two groups. Bipolar line driver circuit can drive together four or six line type stepping motor, although four-wire type machine can only use of bipolar drive circuit, it can greatly reduce the cost of production type to use. Bipolar stepper motor drive circuit is the number of transistors single polarity driving circuit twice, including four bottom transistor is usually driven directly by the micro controller, the upper transistor is demand for the upper drive circuit of the high cost. By accepting the bipolar drive circuit of the transistor voltage, so it is not like the single polarity driving circuit needs same clamp circuit. Figure 2: bipolar stepper motor drive circuit
