BLDC Motor Speed Control with RPM Display

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BLDC Motor Speed Control with RPM Display
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BLDC Motor Speed Control with RPM Display
Introduction

• The main objective of this project is controlling
  speed of BLDC motors with the help of
  microcontroller. To make the industry automation
  the equipment and machineries should be
  controlled automatically. So control of the
  machineries which involving this motor can be
  done accurately. It displays its speed using an
  IR method of speed sensor mechanism. The DC motor
  has various application used in industries like
  in drilling, lathes, spinning, elevators and etc.

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BLDC Motor Speed Control with RPM Display
Why Controlling the Speed of Motor is Essential

• The speed control of a DC motor is very essential
  in industries.
• Controlling the speed has many applications such
  as drilling, spinning, elevators, etc.
• To control the speed of the BLDC motor by varying
  duty cycles of the power fed to it.
• This proposed system provides a very precise and
  effective speed control system.
• The user can increase or decrease the speed as
  per the requirement.

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BLDC Motor Speed Control with RPM Display
Block Diagram
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BLDC Motor Speed Control with RPM Display
Hardware Components

• 8051 Microcontroller
• Level Shifter IC
• GSM modem
• LCD
• LED
• Crystal
• Relay driver IC
• Resistors
• Capacitors
• Diodes
• Transformer
• Voltage Regulator
• Opto Isolator
• Digital Energy Meter
• Lamp

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BLDC Motor Speed Control with RPM Display
Software Requirement

• Keil compiler
• Language Embedded C or Assembly

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BLDC Motor Speed Control with RPM Display
Power supply

• The system requires a regulated 5v supply for
  the semiconductors. These can be delivered from
  the 230V domestic supply. Before applying this to
  the system we must step down this high voltage to
  an appropriate value. After that it should be
  rectified. To achieve 5 V DC we should regulate
  this.
• A step down transformer and a bridge rectifier is
  used here to convert AC to DC. A regulator IC is
  also used here to give constant supply.7805 IC is
  used for power supply.

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BLDC Motor Speed Control with RPM Display
Power supply
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BLDC Motor Speed Control with RPM Display
BLDC Motor

• BLDC motors have a rotor and a stator.
• BLDC motors are a type of synchronous motor.
• The magnetic field generated by the stator and
  the magnetic field generated by the rotor rotates
  at the same frequency.
• BLDC motors do not experience theslip that is
  normally seen in induction motors.

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BLDC Motor Speed Control with RPM Display
Opto - Isolator

• Opto coupler or Opto Isolator is a 6 pin IC. It
  is a combination of 1 LED and a diac. Pin 5 is
  not generally used and when light falls on the
  diac then it switches ON the diac.

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BLDC Motor Speed Control with RPM Display
MOSFET

• The metaloxidesemiconductor field-effect
  transistor (MOSFET, MOS-FET, or MOS FET) is a
  type of transistor used for amplifying or
  switching electronic signals.

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BLDC Motor Speed Control with RPM Display
Voltage Regulator (LM 7805)

• A voltage regulator is designed to automatically
  maintain a fixed voltage level.
• 7805 is a voltage regulator integrated circuit.
• It is a member of 78xx series of fixed linear
  voltage regulator ICs.
• The xx in 78xx indicates the fixed output voltage
  it is designed to provide.
• 7805 provides 5V regulated power supply.

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BLDC Motor Speed Control with RPM Display
IR Sensor

• The IR Sensor is a general purpose proximity
  sensor.
• Here we use it for collision detection.
• The module consists of a IR emitter and IR
  receiver pair.
• The high precision IR receiver always detects a
  IR signal.

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BLDC Motor Speed Control with RPM Display
Three Stages Of Controlling Speed of BLDC Motors

• The Input stage
• The Processing Stage
• The Output Stage

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BLDC Motor Speed Control with RPM Display

• The Input stage
• The input stage consists of entering the required
  speed through switches.
• The Processing Stage
• The processing stage provides RPM reference of
  the motor. A shaft mounted IR sensor interfaced
  to the microcontroller in the circuit.
• The output stage
• The output stage uses a MOSFET being driven by
  the microcontroller output.

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BLDC Motor Speed Control with RPM Display
Working Principle

• The proposed system uses a microcontroller of the
  8051 family and a rectified power supply. A set
  of IR transmitter and photodiode is connected to
  the microcontroller for counting the number of
  rotations per minute of the DC motor as a speed
  sensor. Opto-coupler is connected to trigger the
  MOSFET for driving the BLDC motor which is duly
  interfaced to the microcontroller. Two switches
  are interfaced to the microcontroller for
  controlling the speed.
• The speed control of the DC motor is achieved by
  varying the duty cycles (PWM Pulses) from the
  microcontroller as per the program. The
  microcontroller receives the percentage of duty
  cycles from the switches and delivers the desired
  output to switch the driver IC to control the
  speed of the DC motor. The speed sensed by the IR
  sensor is given to the microcontroller to display
  it on the LCD display.

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BLDC Motor Speed Control with RPM Display
Application

• BLDC machines are used in applications of vital
  importance such as aerospace industry, tool
  drives, actuators and electric vehicle propulsion
  system.

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BLDC Motor Speed Control with RPM Display
Conclusion

• The circuit was designed and implemented. Desired
  rpm was entered through matrix keyboard. Speed of
  motor was displayed on LCD display. IR sensor
  feedback the actual rpm. Motor rotates with 100
  accuracy. Different rpm values were checked and
  corresponding displays were obtained on the LCD
  screen. The proposed method is very useful for
  speed control of BLDC motor.

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