Dc and stepper motor
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Transcript of Dc and stepper motor
Presented by—swaraj nayak
An Introduction to DC and Stepper Motors
ELECTRIC MOTORSELECTRIC MOTORSAn Introduction to DC and An Introduction to DC and Stepper MotorsStepper Motors
Electric MotorsElectric Motors• Electric motors are Electric motors are
everywhere! everywhere! • In your house, almost In your house, almost
every mechanical every mechanical movement that you movement that you see around you is see around you is caused by an AC or DC caused by an AC or DC electric motor. electric motor.
Direct Current MotorsDirect Current Motors• overall plan of
a simple 2-pole DC electric motor
• A simple motor has 6 parts, as shown in the diagram
Direct Current MotorsDirect Current Motors
Direct Current MotorsDirect Current Motors
Brushed DC MotorBrushed DC Motor• The brushed DC The brushed DC
motor is one of the motor is one of the earliest electric earliest electric motor designsmotor designs
• Easy to understand Easy to understand design design
• Easy to control Easy to control speed speed
DC STEPPER MOTORSDC STEPPER MOTORS• Stepping motors are
electric motors without commutators
• Commutation is handled externally by the motor controller
• Controller charges opposite coils attracting the center rotor magnets
DC STEPPER MOTORSDC STEPPER MOTORS
DC STEPPER MOTORSDC STEPPER MOTORS• Voltage Rating Voltage Rating
– provides desired torqueprovides desired torque
• Resistance-per-winding determinesResistance-per-winding determines– the current draw of the motorthe current draw of the motor– Maximum operating speedMaximum operating speed
• Degrees per StepDegrees per Step– Sets the number of degrees the shaft will Sets the number of degrees the shaft will
rotate for each full steprotate for each full step
UNIPOLAR STEPPER UNIPOLAR STEPPER MOTORMOTOR
• Relatively easy to controlRelatively easy to control• simple 1-of-'n' counter circuit can generate the proper simple 1-of-'n' counter circuit can generate the proper
stepping sequencestepping sequence• 1 transistor per winding1 transistor per winding
UNIPOLAR STEPPER UNIPOLAR STEPPER MOTORMOTOR
• two center-tapped coilstwo center-tapped coils• represents the connection of a 4 -phase represents the connection of a 4 -phase
unipolar stepper motorunipolar stepper motor
UNIPOLAR STEPPER UNIPOLAR STEPPER MOTORMOTOR
• 6 wires with a center tap on each of two coils6 wires with a center tap on each of two coils
IDENTIFYING WIRESIDENTIFYING WIRES• Check make and model to see if wire Check make and model to see if wire
colour code is availablecolour code is available• Observe the wires to see if you can Observe the wires to see if you can
identify groups of 3 wiresidentify groups of 3 wires• Measure resistance between wires Measure resistance between wires • Wire with lowest resistance is power Wire with lowest resistance is power
wirewire
IDENTIFYING WIRESIDENTIFYING WIRES• 6 wire motors6 wire motors
– Groups of 3 wiresGroups of 3 wires– 1 power & 2 signal1 power & 2 signal
• 5 wire motors5 wire motors– 1 power & 4 signal wires1 power & 4 signal wires
• power wire has power wire has lowest lowest resistance to the resistance to the othersothers
CONTROL PROGRAMCONTROL PROGRAM• Once wires identified and connected to the circuit: a Once wires identified and connected to the circuit: a
program is needed to run the motorprogram is needed to run the motor• Example Turing Program:Example Turing Program:
looploopparallelput (1)parallelput (1)delay (500)delay (500)parallelput (2)parallelput (2)delay (500)delay (500)parallelput (4)parallelput (4)delay (500)delay (500)parallelput (8)parallelput (8)delay (500)delay (500)
end loopend loop
STEPPER MOTOR STEPPER MOTOR CONTROLCONTROL
• 4 signal wires fired in the correct sequence will turn the motor4 signal wires fired in the correct sequence will turn the motor