The type of DC motor has been widely used in modern electronic products, automatic control systems, electronic instruments and equipment, household appliances, electronic toys, etc.
Familiar recorders, record players, video cameras, electronic computers, etc. , can not lack DC motors.
Therefore, the control of DC motor is a very practical technology.
This paper will introduce the control technology of various DC motors in detail.
DC motors can be roughly divided into four categories: the first category is stepping motors with several phase windings.
These stepping motors, coupled with appropriate sequence pulses, can make the spindle rotate at a precise angle (Usually at 1. 8 °--7. 5 °Between).
As long as the appropriate pulse sequence is applied, the motor can rotate continuously according to people's predetermined speed or direction.
Stepper motors use microprocessors or special stepper motors to drive integrated circuits, which are easy to control.
For example, the commonly used SAAl027 or SAAl024 special stepping motor control circuit.
Stepping motors are widely used in places where accurate measurement of angle rotation is required.
For example, stepping motors are used in the movement of robot arms, character selection of advanced character wheels, magnetic head control of computer drivers, prefix control of printers, etc.
The second type is permanent magnet converter DC motor. Its design is very simple, but it is widely used.
When the rated DC voltage is applied, the rotating speed is almost equal.
This type of motor is used in machines or equipment with fixed speed such as tape recorders, video cameras, record players or CD players.
It is also used for driving devices with a wide range of speed change, such as small electric drills, model trains, electronic toys, etc.
In these applications, it greatly enhances the function of the motor by means of the function of the electronic control circuit.
The third category is the so-called servo motor. The servo motor is the executive element in the automatic device. Its greatest feature is controllable.
When there is a control signal, the servo motor rotates, and the rotation speed is proportional to the control voltage. After removing the control signal voltage, the servo motor stops rotating immediately.
Servo motors are widely used in almost all automatic control systems.
For example, a speed measuring motor whose output is proportional to the speed of the motor;
Or the gear box drives the potentiometer mechanism, and its output is proportional to the position where the potentiometer moves.
When this type of motor is matched with an appropriate power control feedback loop, its speed can be accurately locked with the frequency of the external oscillator or with the external displacement control knob.
The turntable of the phonograph or CD player is commonly used as a servo motor.
Servo motors are also used in antenna rotation systems, remote control model aircraft and ships.
The last type is a two-phase Low Voltage AC motor.
This kind of motor usually supplies a low frequency oscillator with DC power supply, and then uses low frequency and low voltage AC to drive the motor.
This type of motor is occasionally used in the Turntable drive mechanism.
Tag dc motor