Motor control circuit
The motor control circuit controls the speed of each motor therefore steering it around the line. These are very commonly used in robotics. DC motors can rotate in both directions depending upon the polarity of current through the motor. These motors have free running torque and current ideally zero. These motors have high speed which can be reduced with the help of gears and traded off for torque. L293D is a bipolar motor driver IC. This is a high voltage, high current push-pull four channel driver compatible to TTL logic levels and drive inductive loads. It has 600 mA output current capability per channel and internal clamp diodes
L293D motor driver IC . for motor control
We are using DC motor because it is simple to use. DC motors need only two signals for operation. If we need to change its direction we have to change the polarity of the power supply across it. The gear is used to increase the torque to drive the wheel. By using two motors the can can move in any Direction .This mechanism of steering is known as differential driving. The table in the next page shows the mechanism behind moving the robot using two DC motors.