Really .....good

1. Presented by—swaraj nayak
An Introduction to DC
and Stepper Motors

2. ELECTRIC MOTORSELECTRIC MOTORS
An Introduction to DC andAn Introduction to DC and
Stepper MotorsStepper Motors

3. Electric MotorsElectric Motors
• Electric motorsElectric motors
are everywhere!are everywhere!
• In your house,In your house,
almost everyalmost every
mechanicalmechanical
movement thatmovement that
you see aroundyou see around
you is caused byyou is caused by

4. 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

5. Direct Current MotorsDirect Current Motors

6. Direct Current MotorsDirect Current Motors

7. Brushed DC MotorBrushed DC Motor
• The brushed DCThe brushed DC
motor is one ofmotor is one of
the earliestthe earliest
electric motorelectric motor
designsdesigns
• Easy toEasy to
understandunderstand
designdesign
• Easy to controlEasy to control

8. 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

9. DC STEPPER MOTORSDC STEPPER MOTORS

10. DC STEPPER MOTORSDC STEPPER MOTORS
• Voltage RatingVoltage Rating
– provides desired torqueprovides desired torque
• Resistance-per-windingResistance-per-winding
determinesdetermines
– 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 theSets the number of degrees the
shaft will rotate for each full step

11. UNIPOLAR STEPPERUNIPOLAR STEPPER
MOTORMOTOR
• Relatively easy to controlRelatively easy to control
• simple 1-of-'n' counter circuit cansimple 1-of-'n' counter circuit can
generate the proper stepping sequencegenerate the proper stepping sequence

12. UNIPOLAR STEPPERUNIPOLAR STEPPER
MOTORMOTOR
• two center-tapped coilstwo center-tapped coils
• represents the connection of a 4represents the connection of a 4
-phase unipolar stepper motor-phase unipolar stepper motor

13. UNIPOLAR STEPPERUNIPOLAR STEPPER
MOTORMOTOR
• 6 wires with a center tap on each of two6 wires with a center tap on each of two
coilscoils

14. IDENTIFYING WIRESIDENTIFYING WIRES
• Check make and model to see ifCheck make and model to see if
wire colour code is availablewire colour code is available
• Observe the wires to see if youObserve the wires to see if you
can identify groups of 3 wirescan identify groups of 3 wires
• Measure resistance betweenMeasure resistance between
wireswires
• Wire with lowest resistance isWire with lowest resistance is

15. 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 signal1 power & 4 signal
wireswires• power wire haspower wire has
lowestlowest
resistance toresistance to

16. CONTROL PROGRAMCONTROL PROGRAM
• Once wires identified and connected to theOnce wires identified and connected to the
circuit: a program is needed to run thecircuit: a program is needed to run the
motormotor
• Example Turing Program:Example Turing Program:
looploop
parallelput (1)parallelput (1)
delay (500)delay (500)
parallelput (2)parallelput (2)
delay (500)delay (500)
parallelput (4)parallelput (4)
delay (500)delay (500)

17. STEPPER MOTORSTEPPER MOTOR
CONTROLCONTROL
• 4 signal wires fired in the correct4 signal wires fired in the correct
sequence will turn the motorsequence will turn the motor