In our day-to-day life, we frequently use various types of motors such as electrical DC motors, AC motors, synchronous motors, induction motors, stepper motors, and so on. These motors can be operated at various speeds based on the requirement of the application using motor speed control techniques. To control speed of various types of electric motors there are various speed control methods. But in some practical applications, motors are required to operate both in a clockwise direction, anti-clockwise direction, reverse braking, forward braking conditions. These modes of operation of DC motors can be achieved using four quadrant DC motor speed control with microcontroller.
DC Motor Speed Control
The method of controlling the speed of a DC motor or making the DC motors to rotate with intended speed using various DC motor speed control techniques is called as DC motor speed control.
The equation clearly indicates that the speed of DC motor can be changed by controlling other parameters in the equation. If we consider various types of DC motors such as series DC motors, shunt DC motors, and compound DC motors, then the speed of each DC motor can be controlled by varying quantities on the right hand side of the above equation.
DC Motor Speed Control using Microcontroller
The DC motor speed control can be achieved by controlling the rotating part of the motor, i.e., rotor which is to be interfaced to the stationary (motionless) microcontroller block or circuit. So, an interfacing medium called as motor driver IC is required to interface the motor with microcontroller (as shown in the figure below).
Typically, IC L293D having 16 pins (as shown in the figure below) is used for DC motor interfacing with 8051 microcontroller.
Let us discuss about practical application in which four quadrant DC motor speed control with microcontroller is achieved.
Practical Implementation of Four Quadrant DC Motor Speed Control with Microcontroller
To achieve DC motor speed control, we need to interface the DC motor with 8051 microcontroller. The four quadrant operation of DC motor such as clockwise rotation, anti-clockwise rotation, forward braking operation, and reverse braking operation can be performed using 8051 microcontroller based circuits. The project circuit diagram for four quadrant DC motor speed control with 8051 microcontroller is shown in the below figure.
In several industrial applications like movement of conveyer belts in the clockwise and anti-clockwise direction can be done using four quadrant operation of motors. In these cases, the DC motor can be controlled using this method.
The block diagram of four quadrant DC motor speed control with 8051 microcontroller project is shown in the above figure. The microcontroller block is interfaced with DC motor using motor driver IC, the power supply block provides power supply to the project kit, and switch array. This switch array is used to send the control signals to the microcontroller which in turn sends commands to the motor driver IC for controlling the operation of the DC motor.
Fan Speed Controller
The fan speed controller is nothing but controlling the speed of a single phase motor (as ceiling fans are made of single phase induction motors which are usually capacitor-start and capacitor-run type). In this project, a TV remote with Thyristor power control technique is used for controlling the speed of single phase motor. Hence, normal TV remote acts as a fan speed controller. The fan speed controller project circuit is shown in the below figure in which single phase motor of fan is replaced by lamp bulb for demonstration purpose.
The block diagram of fan speed controller project is shown in the below which consists of various blocks such as power supply block, 8051 microcontroller interfacing with the motor (lamp) and seven segment display.
The TV remote control is used for sending various input signals based on which the microcontroller generates firing pulses to thyrsitors. Thus, based on the Thyristor triggering which can be controlled from TV remote the motor can be operated in various speeds. Here, light intensity of the lamp varies for various inputs indicating the motor speed variation.
Stepper Motor Controller
Similar to DC motor speed control, we can also control the operation and speed of stepper motor using different methods. The stepper motor is typically used for application such as automatic door opening system based on PIR sensor, swing control of coolers or air conditioners, sun tracking solar panel, and so on. In these applications, the stepper motor speed, direction of rotation, and angle of rotation has to be controlled based on application requirements. This can be achieved using stepper motor control with 8051 microcontroller.
3 Phase Motor
The 3 phase motor is preferably used in some applications and the speed control of 3 phase motor can be achieved using various types of pulse width modulation techniques (PWM). But, mostly sine wave pulse width modulation and space vector pulse width modulation techniques are frequently used for speed control of 3 phase motor. The below figure represents the diagram of 3 phase motor speed control using SVPWM technique.
Do you want to design electronics projects on your own? You can also share your new innovative project ideas, comments, and suggestions in the comments section below.