BIDIRECTIONAL SPEED CONTROL OF DC MOTOR USING 8051 MICROCONTROLLER

PRESENTED BY:SHANMUKHA SREENIVAS.P

S.PRAVEEN KUMARSANDEEP BONTHU

D. HEMA PRATHYUSHAV.NISHANTHI

INTRODUCTIONThis project deals with bidirectional speed control of DC motor

using 8051 microcontrollerDesign of H bridge dc-dc converter is an IGBT based bridge

circuitThe control circuit consists of the 8051 microcontroller which is

programmed to generate pulses to turn on IGBT’s s per required sequence

The H bridge dc-dc converter is implemented with hardware setup and software program in the 8051 –C code

INTRODUCTION TO DC MOTOR

An electrical motor converts electrical power to mechanical power.

In DC motor power is supplied to the armature directly from a DC source.

Speed of DC motor is controlled by armature voltage control method

As the amount of time that the voltage is ON increases compared with the amount of that is OFF, the average speed of the motor increases

8051 microcontroller :8051 microcontroller is used for firing the dc-dc

converter circuit.

In this program we have used port2 as output port with p2.0, p2.1, p2.2,p2.3 as output pins

The output from port0 is given to H-bridge dc-dc converter circuit

This 8051 uses the program which is already burned(bumped) in the microcontroller and gives required firing output and on the required pins

IGBT H-bridge :

• The outputs of microcontroller are connected to gate terminals of IGBT’s T1, T2, T3 and T4.

• Here T1, T2 are fired for clockwise rotation T3,T4 are fired for counter clockwise rotation.

•This circuit converts fixed dc voltage to variable dc output

•This output is used to run the dc servomotor

LM293D driver circuit:The output of the LM293D driver circuit is given to

the IGBT H-bridge.

•This driver circuit is used for voltage amplification.

•Here the voltage has been amplified from 5 to 12 volts.

7 segment motor rpm display:A 7 segment display is composed of 7 elements

individually ON or OFF, they can be combined to produce simplified representations of the arabic numerals

• The ports p1, p3 are connected to the LEDs of the 7 segment display.

•These are used for displaying the speed of the motor.

Binary switching circuit:The inputs of binary switching circuit are taken from

the port p2 of the 8051 microcontroller .

• Based on the duty cycle the speed of the motor is calculated.

• For that particular speed the binary switching circuit is used.

Applications :

Used in the arm position of robots.

Automatic guided vehicles (AGV).

Microcontroller can be reprogrammed and used as dc-dc convertor, inverter or chopper.

Results and Conclusions

The project “BIDIRECTIONAL SPEED CONTROL OF DC MOTOR USING 8051 MICROCONTROLLER" has been successfully programmed using KEIL & PROLOAD softwares and the output of the dc-dc converter is tested on DC motor.