part 11-elec buk(final)

8/11/2019 PART 11-Elec Buk(Final)

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PART 11INDUSTRIAL ELECTRONICSI. WELDING SYSTEMS

WELDING

The process of joining metals usually by heat or sometimes with pressure andsometimes with an intermediate or filler material with high melting point

1. BASIC INTERVALS

a. Squeeze IntervaWelding electrode comes forward and engage the metal pressing against thesurfaceTypical squeeze time is 1 sec

!. We " IntervaWelding transformer is energized, current flows and creates a weldOn heat subinterval is a condition when the current is onOn cool subinterval is when the current is off Typical duration ( ! 1" sec#

#. $% " IntervaWeld interval is finished

$lectrode pressure is maintained

". Re ea&eWelding electrode is retracted

e. Stan"!' IntervaThe time after release interval to the ne%t start sequence

(. POPULAR WELDING PROCESSES

a. Ar# We ")n*&t is simply the use of electric arc to provide heat

'rocess of utilizing the concentrated heat of an electric arc to join metal byfusion of the parent metal and the addition of metal to joint usually provided bya consumable electrode$ither direct or alternating current may be used for the arc, depending upon thematerial to be welded and the electrode used

Ma#r% Inte*rate" Tra)n)n* an" Rev)e+ Center E ,#-r n)/

)ry*ell


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110( Industrial Electronics

+arious forms of arc welding includes electroslag welding, plasma arc welding,gas metal arc welding, submerged arc welding, gas tungsten arc welding etc

TIG We ")n*as tungsten arc welding

-n arc is formed between a non.consumable tungsten electrode and the metalbeing welded/ome of its benefits includes superior quality welds, precise control of heat,free of splatter and low distortion

MIG We ")n*

as 0etal -rc Welding*ommonly used high deposition rate welding processeferred to as a semiautomatic welding process

2enefits include all position capability, long weld can be made without start andstops and minimal post weld cleaning is required

!. S% )" State We ")n*roup of welding processes which produces coalescence at temperaturesessentially below the melting point of the base materials being joined, withoutthe addition of brazing filler metal'ressure may or may not be used/ometimes called solid state bonding processes&ncludes cold welding, diffusion welding, e%plosion welding, forge welding,friction welding, hot pressure welding, roll welding, and ultrasonic welding

#. Re&)&tan#e We ")n*

uses the application of electric current and mechanical pressure to create aweld between two pieces of metalWeld electrodes conduct the electric current to the two pieces of metal as theyare forged together/ome of its benefits include high speed, easily automated, suitable for high rateproduction and it is economical

S %t We ")n*esistance welding in which the weld is produced by the heat obtained at theinterface between the wor3 pieces

Sea2 We ")n*/pots are very closed to each other that they overlap and ma3e a continuousseam weld

U &et We ")n*esistance welding process applicable to small welding areas

E ,#-r n)/ Ma#r% Inte*rate" Tra)n)n* an" Rev)e+ Center


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Industrial Electronics 11- 3

II. INDUSTRIAL ELECTRONIC DEVICES

1. ELECTRON TUBES

a. T4'ratr%n - gas filled triode used as an electronic switch

!. I*n)tr%n$lectron tube containing mercury and function as a rectifier

(. T$YRISTOR/olid state devices used as a switch in applications that handles larger voltageand currents4ave at least four semiconductor layersegenerative switching devices and cannot operate in linear manner

a. S) )#%n C%ntr% e" Re#t)5)er 6SCR70ost commonly used thyristor Three.terminal device used to control large currents to a load5our layer semiconductor device usually used in relay controls, time delaycircuits, regulated power supply and phase controls



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1108 Industrial Electronics

VBR ! brea3.over voltage+oltage through which /*starts to conduct when gatecurrent is zero

I$ ! holding current

-node current between theconducting state and non.conducting state

SCR Gate C4ara#ter)&t)#&/* is fired by a short burst of current into the gate typically " 1 ! 6" m-

SCR9& C%n"u#t)%n An* e 6CA7The anular degrees of an -* cycle during which the /* is turned on

SCR9& :)r)n* De a' An* e 6:DA7 -ngular degrees of an -* cycle that elapses before /* is turned on


IA

V A

V BR

I$

SCR C$ARACTERISTICS CURVE


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110< Industrial Electronics

E e#tr)#a C4ara#ter)&t)#& %5 Tr)a#

1. Maximum Allowable Main Terminal RMS Current 1-, 8-, 9-, 1"-, 16- and 6-

2. Breakdown Voltage4ighest main terminal pea3 voltage the triac can bloc3 in either directiontypically 1""+, ""+, :""+ and 9""+

3. On Stage Voltage Acro t!e Terminal&deal value is "+Typical value is 1 ! +

A"vanta*e& %5 Tr)a# %ver Me#4an)#a S+)t#4e&;o contact bounce;o arcing across partially opened contactsOperates much faster 0ore precise control element

3. BREA=0OVER DEVICES/mall thyristors which do not switch the main load current e' D)%"e - :.layer diode constructed li3e an /* but without gate terminal


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Industrial Electronics 11- ?

&n terms of firing, it has faster rate than /hoc3ley diode

#. DIAC)iode -**onstructed li3e a T &-* but without a gate terminal


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V @ A+22 B + diode

4. Pr%*ra22a! e Un) un#t)%n Tran&)&t%r 6PUT7/imilar operating characteristics as


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/ynchros are designed for use on either a 116 volt or a 9.volt power sourceOperating frequencies includes either 9" or :"" 4z$lectromagnetic theory forms the basis for all synchro operations

SYNC$RO SYSTEMS*onsist of two or more synchros electrically connected

a. T%rque S'n#4r% S'&te2


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1101( Industrial Electronics

- synchro device that compares two signals, the electrical signal applied to itsstator and the mechanical signal applied to its rotor 4ence the output is anelectrical voltage ta3en from the rotor winding$ O /& ;-C is the name given to the electrical output of the controltransformer

S'n#4r% Ca a#)t%r - unit containing three delta connected capacitors


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a. O en L%% C%ntr% S'&te2

*ontrolled directly by an input signal&t has no feedbac3 and therefore less accurate


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Industrial Electronics 11- 1;

2alanced 'otentiometer in a closed loop servo system is a voltage divider that

functions as a position sensor and produces the error voltage that is fed to theservo amplifier

!. Ve %#)t' Serv%/ame principle of error signal generation as position servo e%cept that thevelocity is being sensed rather than the position

#. A##e erat)%n Serv%/imilar to velocity and position servos e%cept that the acceleration of the load isbeing sensed rather than position or velocityThe tachometer of the velocity loop is replaced with an accelerometer

3. DAMPING

T)2e La*/ervo characteristics defined as the time between the input of the signal andthe actual movement of the load


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1101< Industrial Electronics

:r)#t)%n C ut#4 Da2 )n*/implest type of damping

Ma*net)# C ut#4 Da2 )n*0agnetic coupling uses a magnetic field o draw friction plates together toproduce damping

Err%r0Rate Da2 )n*0ethod of damping that anticipates the amount of overshot*orrects the overshot by introducing a voltage in the error detector that isproportional to the rate of change of the error signal

8. SERVO DEVICES

a. AC Serv% M%t%r&


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Industrial Electronics 11- 1?

GYROSCOPE -pplied to any rapidly spinning object - functional gyroscope is constructed and mountedRate G'r%& are specially mounted so they are free to precess in only onedirection and are used to measure angular rates

PROPERTIES 1. R)*)")t'

Tendency of a spinning wheel to remain in fi%ed position in space

:a#t%r& t4at A55e#t t4e R)*)")t'a weightb shapec speed of rotation of the rotor

(. Pre#e&&)%n'roperty of a gyro that causes it to tilt in a direction perpendicular to thedirection of any outside forceThe direction of precession in a gyro is always G" degrees from the direction of the applied force

C%2 %nent& %5 a Un)ver&a ' M%unte" G'r%1 otor

&nner imbal8 Outer imbal

: 2ase



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1101@ Industrial Electronics

TEST YOURSEL: 11Rev)e+ Fue&t)%n& 1 -n electronic switch that has the highest single device current capacity and can withstandoverloads better

a thyratronsb ignitronsc /*d triac

An&+er c /*

&t is the fusion or growing of the materials being togethera coalitionb coincidencec coalescense

d mi%ing

An&+er c coalescense

8 &dentify which of the following is a three layer devicea /*/b )iacc Triacd '


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9 - Triac is a IIIIIIIII

a terminal switchb terminal bilateral switchc 8 terminal unilateral switchd 8 terminal bidirectional switch

An&+er d 8 terminal bidirectional switch

D -rc welding requires a voltage aroundIIIIIIIIIa 9".1"" +b 16". "" +c :"".::" +d 1""" ! 6""" +

An&+er a 9" ! 1""+

= )uring -rc Welding, the current is in the range of IIIIIIII.a 1 ! 6 -b 6 ! 6" -c 6" ! :"" -d 6"" ! :""" -

An&+er c 6" ! :""-

G The body structure of the car is welded byJa gas weldingb spot weldingc induction weldingd arc welding

An&+er b spot welding

1" - thyristor equivalent of a thyratron tube is IIIIIIIIa diacb triacc /*d '


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Industrial Electronics 11- (1

1= - device that cannot be triggered by voltage of either polarity is IIIII

a diacb triacc /*/d all of the above

An&+er c /*/

1G Technically, what is dicing meansHa process of joining two diacsb circuit of reducing noisec device for reducing magnetic and radio interferenced process of brea3ing the silicon slice into chips

An&+er d process of brea3ing the silicon slice into chips

" The term used to describe the process whereby two transistors with positive feedbac3 are usedto simulate the action of the thyristora -rcingb Catchingc )ampingd /witching

An&+er b Catching

1 &t is the minimum anode current to hold a thyristor at conductiona trigger b maintaining currentc holding currentd threshold voltage

An&+er c holding current

$lectron tube containing mercury functioning as a rectifier a Thyratronb &gnitronc Thyrector d /*

An&+er b &gnitron

8 4ow do you stop the conduction during which the /* is also conductingHa remove voltage gateb increase cathode voltagec interrupt anode currentd reduce gate current

An&+er c interrupt anode current



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110(( Industrial Electronics

: - series * connected in parallel with an /* to eliminate false triggering is theIIIIIIIa crowbar b snubber c varistor d eliminator

An&+er b snubber

6 Which are the three terminals of a T &-*Ha gate, anode1 and anodeb gate, source and sin3c base, emitter and collector d emitter, base1 and base

An&+er a gate, anode1 and anode

9 5or inspection of welding defects in thic3 metals, which of the following ray is used tophotograph thic3 metals objectsH

a gamma raysb cosmic raysc infrared raysd ultraviolet rays

An&+er a gamma rays

D The minimum emitter to base voltage to trigger the


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Industrial Electronics 11- (3

8" This device is two zener diodes connected bac3 to bac3 in series and is used to support voltage

surges and transientsa thyristor b varactor c thyrector d phanatron

An&+er c thyrector

81 efers to the number of degrees o an -* cycle during which the /* is turned O;a conduction angleb firing delay anglec induction angled O; angle

An&+er a conduction angle

8 &t is the name given to the variety of rotary, electromechanical, position sensing devicesHa synchrob gyroc servod motor

An&+er a synchro

88 &t is a system in which a precise movement of a large load is controlled by a relatively wea3control signal

a synchrob servoc gyrod motor

An&+er b servo

8: What is the primary purpose of a synchro systemHa precise and rapid transmission of data between stationsb accurate measurement of distancesc to introduced stability to the systemd gives additional mobility

An&+er a precise and rapid transmission of data between stations

86 This is a very important method used in synchro receivers to prevent the rotor from spinning or oscillating,

a jumpingb precessionc correspondingd damping

An&+er d damping



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89 When will a synchro generate more heat than it is design to handleHa when underloadb when overshootc when overloadd when e%posed to fire

An&+er c when overload

8D When can a ma%imum voltage is induced in the stator coil of a synchroHa when the stator coil rotatesb when the rotor coil is aligned with the stator coilc when both coils rotatesd when the rotor coil is magnetized by the stator coil

An&+er b when the rotor coil is aligned with the stator coil

8= &t is the name given to the electrical output of the control transformer a error signalb correct signalc differential signald error free signal

An&+er a error signal

8G &n a servo system, there are series of overshoots which are 3nown as Ja eatingb climbingc huntingd resting

An&+er c hunting

:" This principle stabilizes a system to minimize the problem of overshoota clampingb fanningc dampingd lagging

An&+er c damping

:1 &t is the property of gyro causing it to tilt in a direction perpendicular to the direction of anyoutside force

a ecessionb Tecessionc 'recessiond 'ost session

An&+er c 'recession



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Industrial Electronics 11- (;

: &t is the tendency of a spinning wheel to remain in fi%ed position in space

a mobilityb rigidityc accuracyd alternativity

An&+er b rigidity

:8 - universally mounted gyro has how many gimbalsHa oneb twoc threed four

An&+er b two

:: &n what direction will a gyro precess in response to an outside forceHa perpendicular to the forceb perpendicular to the spin a%isc parallel to the forced parallel to the spin a%is

An&+er a perpendicular to the force

:6 4ow many degrees of freedom does a rate gyro usually haveHa oneb twoc threed four

An&+er a one

:9 What gyro characteristics provide the basis for the operation of rate gyroHa decisionb precessionc weightd spin

An&+er b precession

:D Of the following term, which accurately describes a synchroHa position sensingb electromechanicalc rotaryd all of the above

An&+er d all of the above



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:= *ontrol systems are used in what particular applicationa light loadb heavy loadc medium loadd all of the above

An&+er b heavy load

:G What is defined as a device that gives an indication usually in the form of a voltage that isproportional to the acceleration to which it is subjectedH (-pril, "":#

a inertia meter b accelerometer c /peedometer d voltmeter

An&+er b accelerometer

6" Who discovered the principle of gyrosHa Ceon 5ocultb Tiger 5ocultc Ceonard 5ocultd ?ohn )avis 5ocult

An&+er a Ceon 5ocult



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part 11-elec buk(final)

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