This document describes a project to control the speed of an induction motor using a touch screen. It discusses the principles of induction motors and different speed control techniques. The touch screen allows for direct interaction to control the motor speed without intermediate devices. It works by using resistive layers in the touch screen and interfacing it with the motor controller to vary the motor speed based on touch location on the screen. The document presents the results of an experiment where touch positions on the screen were mapped to different motor revolutions per minute. It concludes that touch screen control provides a safer, simpler and more reliable user interface compared to conventional switches.

1. LAKIREDDY BALIREDDY COLLEGE OF ENGINEERING
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2. TOUCH SCREEN BASED SPEED
CONTROL OF INDUCTION MOTOR
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IM PRINCIPLE
TYPES OF SPEED CONTROL TECHNIQUES OF
INDUCTION MOTOR
WHY TOUCH SCREEN ??
WORKING OF TOUCH SCREEN
TOUCH SCREEN INTERFACING WITH
INDUCTION MOTOR
CONCLUSION
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4.  DOUBLE REVOVLING FIELD THEORY
 ROTATING MAGNETIC FIELD
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5. Speed control
STATOR SIDE
AC VOLTAGE
CONTROLLERS
ROTOR SIDE
V/F
ROTOR
RESISTANCE
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6.  A touch screen is an electronic visual display that
can detect the presence and location of a touch
within the display area.
 Touch screens can also sense other passive
objects, such as a stylus, stirrer etc.
 Touch screens are common in devices such as allin-one computers, tablet computers, and smart
phones.
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7.  The touch screen has two main attributes.
 First, it enables one to interact directly with what is
displayed, rather than indirectly with a pointer
controlled by a mouse or touchpad.
 Secondly, it lets one do so without requiring any
intermediate device that would need to be held in the
hand (other than a stylus).
 They also play a prominent role in the design of digital
appliances such as the personal digital assistant
(PDA), satellite navigation devices, mobile
phones, and video games.
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11.  Usually a resistive touch screen consists of at least three
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layers:
A flexible membrane made from PET film is suspended
over a rigid substrate made from glass or acryl .
Both surfaces are coated with a transparent conductive
film like ITO (Indium tin oxide).
The conductive ITO layers are kept apart by an insulting
spacer along the edges, and by spacer dots on the inner
surface of the two ITO layers.
In this way there will be no electrical connection unless
pressure is applied to the top sheet (PET film).
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12. ADC;
 An A/D converter with a resolution of 10 bits and the
absolute inaccuracy far under the linearity error of the
touch screen is required for the conversion of the
analog values into digital values.
 I/O PINS:
 The pins driving the touch screen must be able to sink and
source in the range of 5-25mA
 TIMER:
 The timer can be used to trigger the ADC and set the I/O
pins in the correct order immediately before a measurement
starts.
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14.  As mentioned it is possible to determine the force that is
applied on a 4-wire touch screen
 By means of Ohms Law there are two different methods
 The first method requires a known X-plate resistance and
two additional cross-panel measurements (Z1 and Z2) of
the touch screen.
 The second method requires that the X- and Y-plate
resistance values are known but allows the use of a single
measurement only (Z1).methods to determine RTouch
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15.  RTOUCH=RGES-R(X-)-R(Y+)
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=ADC(X)*(R(X)/2(ADC RESOLUTION))R(Y)((1-(ADC(Y))/2(ADC(Y) RESOLUTION)
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22. Touch screen position
SPEED IN
RPM
OUTPUT
VOLTAGE
IN VOLTS
1
190
73
2
245
117
3
350
199
4
600
207
5
774
211
6
stop
stop
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23.  By making use of this technology, we can control the
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equipment in a safe and simpler manner.
It is easy to operate and can be operated by any one.
The danger of electric shock with conventional switches is
also eliminated by using technology.
The power consumed is relatively low compared to
switches.
With constant improvement in touch screen technology it
would be more feasible to use touch screen than the
conventional switches.
Use of this type of control would make the systems more
reliable and long life.
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