1. TWO PHASE BLDC MOTOR SPEED CONTROL USING FUZZY LOGIC CONTROL
Submitted By

2. Introduction Fuzzy controllers are very simple conceptually.
They consist of an input stage, a processing stage, and an output stage.
The project shall be using a microcontroller with a set of switches or a matrix
key pad to define the speed of the BLDC in percentage of its rated speed being
displayed in a LCD display.
The output from the microcontroller drives the motor through a driver circuit.
PWM (Pulse Width Modulation) wave can be used to control the speed of the
motor.
Here the average voltage given or the average current flowing through the
motor will change depending on the ON and OFF time of the pulses
controlling the speed of the motor .

3. EMBEDDED SYSTEMS Definition for :- EMBEDDED SYSTEMS
A combination of hardware and software which together
form a component of a larger machine.
An example of an embedded system is a microprocessor that
controls an automobile engine.
An embedded system is designed to run on its own without
human intervention, and may be required to respond to
events in real time.

4. EMBEDDED SYSTEMS

5. Contents Introduction Block diagram Hardware requirements Power supply
Opto isolator
Hall sensor
Bldc motor
Schematic diagram
Working of the project
Advantages
Applications
Conclusion

6. BLOCK DIAGRAM

7. Hardware requirements
TRANSFORMER (230 – 12 V AC)
VOLTAGE REGULATOR (LM 7805)
MICROCONTROLLER (AT89S52/AT89C51)
PUSH BUTTONS
LCD
1N4007
LED
RESISTOR
CAPACITOR
MC2TE OPTO ISOLATOR
HALLSENSOR
BLDC MOTOR
BC547

8. Hardware Components description
V AC
50 Hz
12V step down
transformer
2. Using In4007 as Bridge rectifier
3. Capacitors Filter(470µf)
4. 5v Regulator
5. Relay

9. 6.Push Buttons
7. OPTO-ISOLATOR
8.IR LED

10. 9. RESISTOR
10. LED

11. 11. Capacitor
13.MOSFET
12.PHOTODIODES

12. Power supply

13. Description of power supply
The circuit uses standard power supply comprising of a step-down transformer from 230v to 12v and 4 diodes forming a Bridge Rectifier that delivers pulsating dc which is then filtered by an electrolytic capacitor of about 470microf to 100microF.
The filtered dc being un regulated IC LM7805 is used to get 5v constant at its pin no 3 irrespective of input dc varying from 9v to 14v.
The regulated 5volts dc is further filtered by a small electrolytic capacitor of 10 micro f for any noise so generated by the circuit.
One LED is connected of this 5v point in series with a resistor of 330ohms to the ground i.e. negative voltage to indicate 5v power supply availability.

14. Block diagram of mc CPU On-chip RAM On-chip ROM for program code
4 I/O Ports
Timer 0
Serial Port
OSC
Interrupt Control
External interrupts
Timer 1
Timer/Counter
Bus Control
TxD RxD
P0 P1 P2 P3
Address/Data
Counter Inputs

15. Microcontroller(at89s52)
• Compatible with MCS®-51 Products
• 8K Bytes of In-System Programmable (ISP) Flash Memory
– Endurance: 10,000 Write/Erase Cycles
• 4.0V to 5.5V Operating Range
• Fully Static Operation: 0 Hz to 33 MHz
• Three-level Program Memory Lock
• 256 x 8-bit Internal RAM
• 32 Programmable I/O Lines
• Three 16-bit Timer/Counters
• Eight Interrupt Sources
• Full Duplex UART Serial Channel
• Interrupt Recovery from Power-down Mode
• Watchdog Timer
• Dual Data Pointer
• Fast Programming Time

16. PIN DIAGRAM OF AT89S52

17. Opto-isolator
Opto coupler is a 6 pin IC. It is a combination of
1 LED and a transistor
Pin 6 of transistor is not generally used and when
light falls on the Base-Emitter junction then it
switches and pin5 goes to zero.
IR LED
An IR LED, also known as IR transmitter, is a special purpose LED that transmits infrared rays in the range of 760 nm wavelength.
They, along with IR receivers, are commonly used as sensors.

18. PHOTODIODES
In this mode the diode is often reverse biased, dramatically reducing the response time at the expense of increased noise.
The reverse bias induces only a small amount of current (known as saturation or back current) along its direction while the photocurrent remains virtually the same.
MOSFET
The metal–oxide–semiconductor field-effect transistor (MOSFET, MOS-FET, or MOS FET) is a device used for amplifying or switching electronic signals.
The channel can be of n-type or p-type and is accordingly called an nMOSFET or a pMOSFET.

19. BLDC motors
Brushless DC motors also known as electronically commutated motors are synchronous electric motor powered by direct current(DC) electricity and having electronic commutation systems, rather than mechanical commutator and brushes .
A BLDC motor has permanent magnets which rotate and a fixed armature, eliminating the problems of connecting current to the moving armature.

20. BLDC motors develop maximum torque when stationary and have linearly decreasing torque with increasing speed as shown in the adjacent

21. LIQUID CRYSTAL DISPLAY (LCD)
Most common LCDs connected to the microcontrollers are 16x2 and 20x2 displays.
This means 16 characters per line by 2 lines and 20 characters per line by 2 lines, respectively.
The standard is referred to as HD44780U, which refers to the controller chip which receives data from an external source (and communicates directly with the LCD.

22. If an 8-bit data bus is used the LCD will require 11 data lines
LCD BACKGROUND
If an 8-bit data bus is used the LCD will require 11 data lines
(3 control lines plus the 8 lines for the data bus)
The three control lines are referred to as EN, RS, and RW
EN=Enable (used to tell the LCD that you are sending it data)
RS=Register Select (When RS is low (0), data is treated as a command)
(When RS is High(1), data being sent is text data )
R/W=Read/Write (When RW is low (0), the data written to the LCD)
(When RW is low (0), the data reading to the LCD)

23. BIBILOGRAPHY
“The Microcontroller and Embedded systems” by Muhammad Ali Mazidi and Janice Gillispie Mazidi , Pearson Education.
ATMEL 89S52 Data Sheets.

24. QUERIES ?

25. THANKYOU