Question

How to control semiconductors with stepper motors? Semiconductor control stepper motor solutions

Comments

Stepper motor unipolar driver In a unipolar stepper motor, all stator windings share a common terminal, and the free terminals of each winding are connected to independent power switches, and current flows in the motor windings in one direction.

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How to realize the basic control of stepper motor?

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Stepper motors are controlled by pulse signals, generally a single-chip microcomputer used to generate a certain frequency pulse (pulse frequency is used to control speed), and drive and control stepper motors through signal isolation amplification (reaching the voltage of the drive motor).

　　You can use single-chip microcomputer + fully integrated stepper motor driver chip to complete the application, which is relatively simple and convenient to control. It can be combined with ordinary 51 microcontrollers like AT89C2051 or STC12C1052 + THB7128 or THB6064. The single-chip microcomputer determines the number of pulses output according to the input, and allows the stepper motor to drive the chip to convert the success rate signal to drive the stepper motor. Because it is a pulse step by step, the number of pulses output should also take into account the problem of subdivision number, and the program of fixed rotation steps and angle is still relatively easy to compile. Like a 1.8-degree stepper motor, when subdivided into 2, it takes 400 pulses to turn one, 200 pulses to rotate half a turn, 100 pulses to rotate 90 degrees, and so on.

Answer 1

MOS transistors are semiconductor devices. That is, metal-oxide-semiconductor FET, which is a semiconductor device based on the principle of field effect.

So how does a stepper motor control a MOS tube?

MOS tube control of stepper motor refers to the method of using MOS tube to drive and control the stepper motor. MOS transistor (Metal-Oxide-Semiconductor Field-Effect Transistor) is a semiconductor device with high and low resistivity two states, which can control the on state by adjusting the external voltage.

In the MOS tube control of stepper motors, a four-pole MOS tube is commonly used, which has four terminals: source, drain, control and base. When controlling a stepper motor, the source and drain are usually connected to the phase line of the stepper motor (that is, the output of the drive circuit), the control pole is connected to the output of the control circuit, and the base is connected to ground. When the voltage at the control electrode rises, the MOS tube is turned on, so that the phase line of the stepper motor flows through the MOS tube, driving the stepper motor to rotate.

By adjusting the on-state of the MOS tube, the direction of rotation and speed of the stepper motor can be controlled. In order for the stepper motor to rotate precisely, it is also necessary to precisely control the on-time of the MOS tube, which requires the control circuit to produce an accurate pulse signal.