Microprocessor Based Speed Control of DC Motor

We all know the popularity of DC Motors with all type of projects involve either rotational motion such as mini cars or some type of mechanical movement such as Robots. Moreover, these motors are also used in DC Fans. This example will make it easier for you to understand its uses. Suppose we build a robot arm and we would like it to lift certain things from the table.  In an uncontrolled DC motor, it may try to lift object before even getting complete information regarding location of the object, distance of the object and amount of movement require by the arm and robot to reach the object.But, in the case of controlled motor, Robots will get enough time to analyze the situation using sensor and lift the object slowly and steadly without breaking anything. 

Similarly in Remote control cars, if we want to increase or decrease the speed, we can use this project.

This project works on very simple and basic concept. Whenever we switch on the supply, it will take some time for motor to gain its full speed and similarly when we switch off the supply, motor will starts to slow down and eventually stops. To Control the speed, we will use this concept so we can on and off suply in a controlled manner using Microprocessor. Basically Microprocessor is a device which takes binary data as input and do calculations and produce output based on the code written on it. In this case, we will write program which will toggle the on and off button in quick succession to regulate the speed of motor.  The technical term for this switching on and off thing is pulse-width modulation (PWM). So basically, if machines stays in on mode for longer period of time than in off mode, this will increase the speed similarly if machine stays in OFF mode more than it is on ON mode, than it will get slow down.

The program which guides microprocessor in producing its output can be written in C. When you scroll down at the bottom of attached pdf, you will find the exact code with little explaination above.

dc-motor


Useful PDF:

DC Motor Speed Controlled PDF 

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