Actuator part of an Autonomous Robot (AR) system

                         Dear friends, today I am presenting the last part of AR system that is the actuator part. Actuator means , it , in actual performs the specific task that we always targeted from an robotic system. In the case of AR, actuator part simply means moving the robot in various direction.
                         Actuator part of AR system simply consists of an Toy motor. Image of toy motor is below

                            The difference between toy motor and any other DC motor is torque. Generally rating of toy motor with respect to torque is low. So it is more preferable in general line follower project because of low power requirement. This will directly affect on power requirement of the battery or a cell that being used in the system.
                             To drive motors there will be more requirement of current. This requirement not always fulfilled by an micro-controller output. Though the output of an controller is an binary ( logic 0 and logic 1) there is an technique called Pulse Width modulation ( PWM )

                             This is a standard output table of arduino. The PWM technique controls the speed of toy motor. In case of arduino, there is a separate function analogWrite( 0-255 ) the argument in the bracket is a integer between 0 to 255. So my original point is to drive the toy motor with an appropriate current. The requirement of current for arduino is near about 150- 170 mA  please note that this is an practical value of arduino that I have measured in the lab, this value may differ in different case. The operating range of voltage is between 12- 20 V.  A toy motor generally requires near about 800 - 950 mA . Therefore an additional driver circuit is required. The driver circuit should be current buffer. Right now I am working with amplifiers to buffer the current level, On our robot we have used an current driver IC L293D. But this IC leaks current after a period of some months. In short drift property of this IC is very low. In initial stages you can prefer this IC for driver circuit purpose. I hope you will go through its datasheet which is readily available on Google. At the end, I conclude the AR system with driver part. Now you are capable to prepare an autonomous robot. I know that I have given very generalized discussion of it. While doing the project, If  find some difficulty, you can directly leave an comment with your problem. Please do not forget to mention your robot details so that it will be easy for me to solve your problems. Thank you.
 
++++++++++++++++++++++++++++++++++++

An intelligent person is never afraid or ashamed to find their errors in their understanding of things.

++++++++++++++++++++++++++++++++++++