DC MOTOR SPEED AND DIRECTION CONTROL USING IR
The main aim of this project is to control the speed and direction of DC motor using IR remote. For controlling the speed we are using PWM technique.
A pulse width modulator (PWM) is a device that may be used as an efficient DC motor speed controller or light dimmer. This project is a versatile device that can control DC devices which draw up to a few amps of current.
A PWM circuit works by making a square wave with a variable on-to-off ratio, the average on time may be varied from 0 to 100 percent. In this manner, a variable amount of power is transferred to the load. The main advantage of a PWM circuit over a resistive power controller is the efficiency, at a 50% level, the PWM will use about 50% of full power, almost all of which is transferred to the load, a resistive controller at 50% load power would consume about 71% of full power, 50% of the power goes to the load and the other 21% is wasted heating the series resistor.
One additional advantage of pulse width modulation is that the pulses reach the full supply voltage and will produce more torque in a motor by being able to overcome the internal motor resistances more easily.
Rotating the motor anticlockwise or clockwise, or increasing or decreasing the speed of the motor can be done easily with an IR remote without actually going near the motor switches and operating them manually. The manual operation of the motor is completely avoided in this project.
IR remote acts as the transmitter in this project. When a button is pressed in the remote, the signal will be passed and received by the IR receiver that is TSOP 1738 Receiver. The frequency of IR used in this project is 38 KHz. This signal is sent to the microcontroller which decodes the signal and performs the corresponding action in accordance with the button pressed in the remote.
The direction and speed level will be indicated through LEDs.
This project uses regulated 5V, 500mA & 12V, 500mA power supply. 7805 three terminal voltage regulator is used for voltage regulation. Bridge type full wave rectifier is used to rectify the ac out put of secondary of 230/12V step down transformer.
SOFTWARE AND HARDWARE TOOLS:
- Keil compiler
- Microcontroller AT89S52.
- L293D H bridge motor driver
- IR remote
- TSOP1738 IR Receiver
- DC motor