Stepping motor drive work principle Sometimes from some old equipment to remove the stepping motor

Stepping motor drive work principle Sometimes from some old equipment to remove the stepping motor (this kind of motor general no damage) to rotary joints rehashing it use, general need to design drive. The following case is from a Japanese old on the printer to remove the stepping motor and the design of drive. First introduces the working principle of stepping motor, and then introduces the software and hardware design of the driver.

1. The working principle of stepping motor The stepping motor for suites phase stepping motor, using single polarity dc power supply. As long as the stepper motor each phase winding in the right sequence power on, can make the stepping motor stepping rotation. Figure 1 is the four phase reaction stepping motor working principle diagram. Figure 1 four phase stepping motor stepping schematic diagram At the beginning, switch SB switch on the power, SA, SC, SD disconnect, B phase pole and rotor 0, 3 tooth alignment, at the same time, the rotor's 1, 4 tooth and C, D phase winding pole produce wrong tooth, 2, 5 tooth and D, A phase winding pole produce wrong tooth. When switch SC switch on the power, SB, SA, SD disconnect, due to rotary union C phase winding magnetic line of force and 1, 4 teeth between magnetic line of force in the role of the rotor rotation, 1, 4 tooth and C phase winding pole alignment. And 0, 3 teeth and A and B phase winding produce wrong tooth, 2, 5 number teeth and A, D phase winding pole produce wrong tooth. And the like, A, B, C, D four phase winding turns power supply, the rotor will be along the A and B, C, D rotation direction. Four phase stepping motor in accordance with the order of energizing is different, can be divided into the single four shoot, double four shoot, eight take three ways of working. Single 4 beats and double four shot the step Angle equal, but single four shot the rotational torque is little. Eight pat working style, step Angle is single 4 beats and double four took half, therefore, eight pat mode not only can keep high rotational moment and can improve control accuracy. Single four shoot, double 4 beats and eight take work mode of power supply power on timing and waveform respectively as shown in figure

2. A, b, c shows: Figure 2. Stepping motor work sequence oscillogram 2. Based on AT89C2051 stepping motor drive system circuit principle AT89C2051 will control pulse from the mouth of P1 P1.4 ~ P1.7 output, the 74 ls14 reversed phase after the 9014, the 9014 after amplification control photoelectric switches, photoelectric isolation, the power tube TIP122 will pulse signal voltage and current amplifier, driver stepping motor of each phase winding. Make stepping motor with different pulse signal, respectively are turning, inversion, acceleration, deceleration and stop such action. Diagram L1 for stepping motor of a phase winding. AT89C2051 choose frequency and the MHZ crystal oscillator, choose high crystal oscillator purpose is in order to fiber optic rotary joint minimize the mode 2 AT89C2051 of superior machine pulse signal cycle influence. In figure 3 RL1 ~ RL4 for winding resistance, 50 Ω resistance is a external resistance, the current limiting function, is also a improve circuit time constant of the element. D1 ~ D4 for fly-wheel diode, make the motor winding produce counter electromotive force through the fly-wheel diode (D1 ~ D4) and attenuation off, so as to protect the power tube TIP122 from being damaged.