ABSTRACT
In this paper it is to be highlighted that, the functionality of D. C. motor in combination with photo device to work as stepper motor. The heart of this system is a photo device as they have fast response, low cost, compactness and compatibility. The D. C. motor with simple additional gear arrangement and simple feedback system, which can be control by simple microprocessor with short instruction, can work as stepper motor. In this arrangement it is observed that this combination gives comparatively better performance than stepper motor as low cost, small step angle, less weight, better torque characteristics, low power requirement, etc. So, this can be the most efficient solution in the future of smart industrial control, if simple modification is made on the limitation such as brush maintenance, noise of gears and inertia problem of big DC motors by using brushless DC motor, by using the helical gear train and by special electrical and mechanical respectively.
In today’s automatic world the entire machine control becomes “Intelligent”. This intelligence is offered by the tiny but smart microprocessor. The microprocessor forms
the brain of these automatic machines: it is requires mechanical machine, which understand the language of the microprocessor i.e. ‘0’s and ‘1’s. For this purpose until we are using popularly called as ‘Stepper motors’. So today’s formula is
Automation = Microprocessor + Stepper motor
But the cost and the circuit complexity are increasing, although accuracy and precision is increasing, for which we are paying the price. We are having with an alternative “The simple D. C. Motor and photo device with simple additional arrangement”. So the new formula will be
Automation = Microprocessor + D. C. motor + Photo Devices
ADVANTAGES OFFERED BY STEPPER MOTOR: -
1. It can convert the digital pulses fed to it into discrete mechanical movements. For the movement of the stepper motor it requires the pulses into the stator windings in proper sequence. The pulses fed are of digital nature either the current is flowing or not.
2. As the motor works with the digital signal i.e. pulses it can easily interfaced with the microprocessor or controller. The pulses provided to the windings must have a definite sequence, which can be easily provided by the microprocessor.
3. Controlling the pulses fed to the motor can easily control of the rotation. The direction of the rotation is dependent upon the sequence of the pulses fed to the motor, not on the polarity of the supply so by just reversing the sequence of pulses fed; the direction of rotation can be changed. This is very easy with help of the microprocessor, as it only of the programmed software.
4. The speed of the motor or the R.P.M. of the motor is very just the frequency of pulses or ‘Step rate’ has to be increased which also done through the software.
5. The rotor remains locked in the position in which the last step was taken at any time two windings are always energized which locks rotor electromagnetically.
6. These motors can be programmed in three parameters: -
1. Direction
2. Speed
3. Number of steps.
7. These motors are having high torque at low R.P.M. The torque is constant whether the motor is running or standstill.
8. These are special, controllers available for interfacing the Stepper Motors with the microprocessors, which greatly simplifies and facilitates the working with the stepper motors.
9. These motors are having high torque is constant whether the motor is running or standstill.
10. There are special controllers available for interfacing the Stepper Motors with the microprocessors, which greatly simplifies and facilitates the working with the stepper motors. Thus after seeing the advantages the main reasons for which the stepper motors are preferred are as follows.
1. Microprocessor Compatible
2. The direction of rotation is software controlled.
3. The speed is also software controlled.
4. For a given pulse the mechanical displacement is known
(Depends on the mode in which motor operates.)
DISADVANTAGES OF USING STEPPER MOTORS: -
Besides previously mentioned advantages the use of Stepper Motor suffers from the following drawbacks as
1. These motors are very costly.
2. The R.P.M. hardly crosses the limit of 1000.
3. The dynamic torque of the motor reduces as the speed increases.
4. These motors requires driver circuitry when works along with the microprocessor which is costly affair.
5. When the motor stands still, two windings remain energized consumes unnecessary power which is same as it consumes during the running condition.
6. At high loads as the R.P.M increases due to the sleep precision of the movement diminishes.
7. The main drawback of the Stepper Motor is that the operation is open loop i.e. if load is intermittent there is no guarantee of the rotation of the shaft and in programming is it assumes that if pulse is applied rotation is confirmed.
These limitations can be overcome by using the system as shown below.
Ir Tx-Rx Pair for Rotation Measurement
PRINCIPLE OF WORKING: -
As motor start the photo devices the are, transmitter and receiver pair the pulse according to the stepper of motor. These pulses are monitored by microprocessor and give the stop signal to motor as the required position achieved by shaft in combination with proper gear train. This gives us required step angle. Using this system improvement in minimum step angle, a torque speed characteristic possible.
TORQUE Vs SPEED CHARACTERSTICS: -
Thus using the simple D.C. motor main objectives are achieved.
Comparison of Simple D.C. Motor and Stepper Motor: -
ADVANTAGES USING THE SIMPLE STEPPER MOTOR:-
1. Operation is close loop, (i.e. for rotation of the D.C. Motor the rotational feedback is available and programmer has to make use of this signal in programming, so ultimately he is always knows whether the motor shaft is rotating or not.)
2. Cost is less.
3. Power required is less.
APPLICATIONS: -
1. It can be used in all types of automation application.
2. It can be used in Robotics.
3. In printers, graph plotters, automobiles.
4. Several industrial applications.
FUTURE DEVELOMPENT: -
1. Instead of using the conventional D.C. Motor one can use brush less D.C.
Motor.
2. Using the helical gear train can reduce the noisy operation.
3. The problem in ease of big D.C. Motors can be over come special electrical and mechanical modification.
In this paper it is to be highlighted that, the functionality of D. C. motor in combination with photo device to work as stepper motor. The heart of this system is a photo device as they have fast response, low cost, compactness and compatibility. The D. C. motor with simple additional gear arrangement and simple feedback system, which can be control by simple microprocessor with short instruction, can work as stepper motor. In this arrangement it is observed that this combination gives comparatively better performance than stepper motor as low cost, small step angle, less weight, better torque characteristics, low power requirement, etc. So, this can be the most efficient solution in the future of smart industrial control, if simple modification is made on the limitation such as brush maintenance, noise of gears and inertia problem of big DC motors by using brushless DC motor, by using the helical gear train and by special electrical and mechanical respectively.
In today’s automatic world the entire machine control becomes “Intelligent”. This intelligence is offered by the tiny but smart microprocessor. The microprocessor forms
the brain of these automatic machines: it is requires mechanical machine, which understand the language of the microprocessor i.e. ‘0’s and ‘1’s. For this purpose until we are using popularly called as ‘Stepper motors’. So today’s formula is
Automation = Microprocessor + Stepper motor
But the cost and the circuit complexity are increasing, although accuracy and precision is increasing, for which we are paying the price. We are having with an alternative “The simple D. C. Motor and photo device with simple additional arrangement”. So the new formula will be
Automation = Microprocessor + D. C. motor + Photo Devices
ADVANTAGES OFFERED BY STEPPER MOTOR: -
1. It can convert the digital pulses fed to it into discrete mechanical movements. For the movement of the stepper motor it requires the pulses into the stator windings in proper sequence. The pulses fed are of digital nature either the current is flowing or not.
2. As the motor works with the digital signal i.e. pulses it can easily interfaced with the microprocessor or controller. The pulses provided to the windings must have a definite sequence, which can be easily provided by the microprocessor.
3. Controlling the pulses fed to the motor can easily control of the rotation. The direction of the rotation is dependent upon the sequence of the pulses fed to the motor, not on the polarity of the supply so by just reversing the sequence of pulses fed; the direction of rotation can be changed. This is very easy with help of the microprocessor, as it only of the programmed software.
4. The speed of the motor or the R.P.M. of the motor is very just the frequency of pulses or ‘Step rate’ has to be increased which also done through the software.
5. The rotor remains locked in the position in which the last step was taken at any time two windings are always energized which locks rotor electromagnetically.
6. These motors can be programmed in three parameters: -
1. Direction
2. Speed
3. Number of steps.
7. These motors are having high torque at low R.P.M. The torque is constant whether the motor is running or standstill.
8. These are special, controllers available for interfacing the Stepper Motors with the microprocessors, which greatly simplifies and facilitates the working with the stepper motors.
9. These motors are having high torque is constant whether the motor is running or standstill.
10. There are special controllers available for interfacing the Stepper Motors with the microprocessors, which greatly simplifies and facilitates the working with the stepper motors. Thus after seeing the advantages the main reasons for which the stepper motors are preferred are as follows.
1. Microprocessor Compatible
2. The direction of rotation is software controlled.
3. The speed is also software controlled.
4. For a given pulse the mechanical displacement is known
(Depends on the mode in which motor operates.)
DISADVANTAGES OF USING STEPPER MOTORS: -
Besides previously mentioned advantages the use of Stepper Motor suffers from the following drawbacks as
1. These motors are very costly.
2. The R.P.M. hardly crosses the limit of 1000.
3. The dynamic torque of the motor reduces as the speed increases.
4. These motors requires driver circuitry when works along with the microprocessor which is costly affair.
5. When the motor stands still, two windings remain energized consumes unnecessary power which is same as it consumes during the running condition.
6. At high loads as the R.P.M increases due to the sleep precision of the movement diminishes.
7. The main drawback of the Stepper Motor is that the operation is open loop i.e. if load is intermittent there is no guarantee of the rotation of the shaft and in programming is it assumes that if pulse is applied rotation is confirmed.
These limitations can be overcome by using the system as shown below.
Ir Tx-Rx Pair for Rotation Measurement
 |
| SIMPLE DC MOTOR GEAR |
As motor start the photo devices the are, transmitter and receiver pair the pulse according to the stepper of motor. These pulses are monitored by microprocessor and give the stop signal to motor as the required position achieved by shaft in combination with proper gear train. This gives us required step angle. Using this system improvement in minimum step angle, a torque speed characteristic possible.
TORQUE Vs SPEED CHARACTERSTICS: -
Comparison of Simple D.C. Motor and Stepper Motor: -
ADVANTAGES USING THE SIMPLE STEPPER MOTOR:-
1. Operation is close loop, (i.e. for rotation of the D.C. Motor the rotational feedback is available and programmer has to make use of this signal in programming, so ultimately he is always knows whether the motor shaft is rotating or not.)
2. Cost is less.
3. Power required is less.
APPLICATIONS: -
1. It can be used in all types of automation application.
2. It can be used in Robotics.
3. In printers, graph plotters, automobiles.
4. Several industrial applications.
FUTURE DEVELOMPENT: -
1. Instead of using the conventional D.C. Motor one can use brush less D.C.
Motor.
2. Using the helical gear train can reduce the noisy operation.
3. The problem in ease of big D.C. Motors can be over come special electrical and mechanical modification.
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