Stepper motor this paper first provides stepper motor add dynamic torque method. According to the different speed of high and low, add the torque when the solution is not the same. And solution both the stepper motor, and drive circuit. 1, the step motor at low speed when adding torque method 1)Choose the steps from the Angle of small step motor in low speed torque vary with the rotor teeth add. Choose the steps from the Angle of small stepper motor to achieve high torque. HB type rotor teeth on a dozen such as 50 tooth, permanent magnet magnetic flux leakage will be added, but will step in proportion, this conclusion in 100 teeth of the following are useful. From 1 type three-phase HB stepping motor. 2 (Rotor 50 tooth)Changes to 0. 6 (Rotor 100 teeth)。 Add 1. 4 to 1. Eight times torque at low speed. 2)Bipolar connection (3)Efficiency can cover 2 times. It is easy to buy on the market two phase unipolar or bipolar stepper motor, but bipolar drive power tube is larger than that of unipolar. Add 2, stepper motor in high speed torque method 1)Decline in number of turns, reduce L in motor manufacturers specifications of the products selected small inductance L, rated current. Figure 8. 1 the same as the input to insist on low speed, winding circle number changes hungry two - phase type HB stepping motor speedThe comparison of torque characteristics. At high speed, the larger the rated current (The same number of ampere turns, number of turns less)The bigger, the motor torque (Motor for two phase, HB, 1. 8, 56 mm, 54 mm)。 2)Permanent magnet flux to produce small as maternity leave can't reduce the permanent magnets, the ability to add air gap, decreased when the high-speed counter potential, add current, make the torque increases, the speed -Torque characteristics from low speed to high speed into a straight line, when high speed torque, echo frequency also add together. 3)Select step from the Angle of motor. , 3, step motor running at a high speed progress in terms of driving circuit torque method 1)The progress of the drive current voltage to maintain high speed large torque, will adhere to constant current, make in the condition of constant current chopper assignments. To make a constant current can only progress pulse frequency. When as a stepping motor velocity must be high speed, because the voltage constraints, can only work in the condition of the constant voltage, if the input voltage, progress is able to make it still can work at high speed in the constant current situation, if the input voltage, progress is able to make it still can work at high speed in the constant current situation, thus progress at high torque. 2)Decline in driving circuit shut off when the current in the coil current at the time of power tube shut off, due to the current rate of change is big, very big induced voltage occurs in the coil, there is a risk the breakdown of power tube, usually there will be a maintenance circuit.
