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LAKIREDDY BALIREDDY COLLEGE OF ENGINEERING

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TOUCH SCREEN BASED SPEED

CONTROL OF INDUCTION MOTOR

PRESENTED BY:

N.BHAVYA

CH.GAYATHRI

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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

CONTENTS

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DOUBLE REVOVLING FIELD THEORY ROTATING MAGNETIC FIELD

IM PRINCIPLE

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TYPES OF SPEED CONTROL TECHNIQUES OF INDUCTION MOTOR

Speed control

STATOR SIDE ROTOR SIDE

AC VOLTAGE CONTROLLERS

V/FROTOR

RESISTANCE

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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 all-in-one computers, tablet computers, and smart phones.

Why touch screen ???

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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.

Strond heads

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APPLICATIONS

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Resistive touch screen

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CROSS- SECTIONAL VIEW

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Usually a resistive touch screen consists of at least three 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).

STRUCTURE OF TOUCH SCREEN

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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.

Requirements for a touch screen

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SCHEMATIC OF 4 WIRE RESISTIVE TOUCH SCREEN

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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

Calculation of the 4-wire touch pressure

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RTOUCH=RGES-R(X-)-R(Y+) =ADC(X)*(R(X)/2(ADC

RESOLUTION))-R(Y)((1-(ADC(Y))/2(ADC(Y) RESOLUTION)

Calculation of RTouch.

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TOUCH SCREEN INTERFACING WITH INDUCTION MOTOR

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X-position measurement

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Interface of ts with psoc

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Cpld and timer interface

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Triac ckt

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o/p wave forms os Zcd ckt

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Touch screen position SPEED INRPM

OUTPUTVOLTAGEIN VOLTS

1 190 73

2 245 117

3 350 199

4 600 207

5 774 211

6 stop stop

Speed control table

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By making use of this technology, we can control the 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.

conclusion

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THANK YOU

THANK YOU

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QUERRIES