Working of daily household devices

7/24/2019 Working of daily household devices

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Birla Science Museum

How it works ?

How things work

Door Closer

There are two kinds of door closers.

The rst looks like this and is typically used on screen doors and

storm doors:

Inside the cylinder is a spring.

There is also an air cylinder. When you open the door, thecylinder lls with air.

When the door is closing, the spring pushes a piston, whichforces the air out of the cylinder through a small hole. The

Storm oor !loser "ydraulic oor

Working


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How it works ?leaking air creates the hissing noise that you normally hearwith these door closers.

To Install

The second type of door closer is hydraulic and looks somethinglike this:

to Install

"ydraulic oor

Working


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How it works ?

It works on the same principle, using a spring to pro#ide the closing

force. But instead of air to slow the spring down, these closers use

a lightweight oil in a conguration that is a lot like a shock

a$sor$er.

How things work

Cistern Tank

There are se#eral interrelated components that make a toilet do

what it does, as shown here:

If you take o% the tank co#er and peer inside, you will see all of

these parts. They might look slightly di%erent in your particular

toilet, $ut they are all there in one form or another. The three main

systems that work together are:

&The $owl siphon

&The 'ush mechanism
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How it works ?&The rell mechanism

(et)s look at each of these parts separately until the secrets of thetoilet are re#ealed.

Water Tap

When closed:**

When open :*


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How it works ?

How it works ?

How CD (Compact Disc ) works :-

CD:-A Compact Disc (CD) is an optical disc used to store digital data.

Working:-CD-ROM drives employ a near-infrared 7! nm laser diode. "#e laser $eam is

directed onto t#e disc via an opto-electronic trac%ing module& '#ic# t#en detects '#et#er

t#e $eam #as $een reflected or scattered.

What makes a CD ?

A CD is made up of a polycar$onate plastic %no'n as Polymethyle Meta Acrylic.

"#e surface of t#e CD is coated 'it# a t#in layer of aluminium to ma%e it reflective& and is

protected $y a film of lacuer t#at is normally spin coated directly on top of t#e reflective

layer& upon '#ic# t#e la$el print is applied.

Data Storage

CD data are stored as a series of tiny indentations %no'n as pits*& encoded in a spiral trac%molded into t#e top of t#e polycar$onate layer. "#e areas $et'een pits are %no'n as


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How it works ?lands*. +ac# pit is appro,imately !! nm deep $y !! nm 'ide& and varies from ! nm to

/. 0m in lengt#.

How CD Retrieve data?

How it works ?

Vacuum Cleaner

Inside +acuum !leaner
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How it works ?

Working:-

1#en you plug t#e vacuum cleaner in and turn it on& t#is is '#at #appens:

"#e electric current operates t#e motor. "#e motor is attac#ed to t#e fan& '#ic# #as

angled $lades (li%e anairplanepropeller).

As t#e fan $lades turn& t#ey force air for'ard& to'ard t#e e,#aust port (c#ec% out 2o'Airplanes 1or%to find out '#at causes t#is).

1#en air particles are driven for'ard& t#e density of particles (and t#erefore t#e air

pressure) increases in front of t#e fan and decreases $e#ind t#e fan.

"#is pressure drop $e#ind t#e fan is 3ust li%e t#e pressure drop in t#e stra' '#en you sip

from your drin%. "#e pressure level in t#e area $e#ind t#e fan drops $elo' t#e pressure

level outside t#e vacuum cleaner (t#e am$ient air pressure). "#is creates suction& a

partial vacuum& inside t#e vacuum cleaner.

"#e am$ient air pus#es itself into t#e vacuum cleaner t#roug# t#e inta%e port $ecause

t#e air pressure inside t#e vacuum cleaner is lo'er t#an t#e pressure outside.

As long as t#e fan is running and t#e passage'ay t#roug# t#e vacuum cleaner remains open& t#ere

is a constant stream of air moving t#roug# t#e inta%e port and out t#e e,#aust port. 4ut #o' does a

flo'ing stream of air collect t#e dirt and de$ris from your carpet5 "#e %ey principle is friction.

How it works ?
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How it works ?Refrigerator

The left*hand side of the picture shows what)s happening inside the chiller

ca$inet where you keep your food-. The dotted line and pink area show the

$ack wall and insulation separating the inside from the outside. The right*hand

side of the picture shows what)s going around the $ack of the fridge, out of

sight.

. The coolant is a li/uid as it enters the e0pansion #al#e yellow-. 1s it

passes through, the sudden drop in pressure makes it e0pand, cool, andturn into a gas 2ust like a li/uid aerosol turns into a cool gas when you

spray it out of a can-.

3. 1s the coolant 'ows around the chiller ca$inet usually around a pipe

$uried in the $ack wall-, it a$sor$s and remo#es heat from the food

inside.

4. The compressor s/uee5es the coolant, raising its temperature and

pressure. It)s now a hot, high*pressure gas.

6. The coolant 'ows through thin radiator pipes on the $ack of the fridge,gi#ing out its heat and cooling $ack into a li/uid as it does so.

7. The coolant 'ows $ack through the insulated ca$inet to the e0pansion

#al#e and the cycle repeats itself. So heat is constantly picked up from

inside the refrigerator and put down again outside it.


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How it works ?

How it works ?

Rela

1 relay is a simple electromechanical switchmade up of an

electromagnetand a set of contacts.

Pole and hrow

Relays #ave t#e e,act 'or%ing of a s'itc#. 6o& t#e same concept is also applied. A relay is said tos'itc# one or more poles. +ac# pole #as contacts t#at can $e t#ro'n in mainly t#ree 'ays. "#ey are

!ormally "#en Contact $!"% 8O contact is also called a ma%e contact. 9t closes t#e

circuit '#en t#e relay is activated. 9t disconnects t#e circuit '#en t#e relay is inactive.

!ormally Closed Contact $!C% 8C contact is also %no'n as $rea% contact. "#is is

opposite to t#e 8O contact. 1#en t#e relay is activated& t#e circuit disconnects. 1#en t#e

relay is deactivated& t#e circuit connects.

Relays are also named with designations like

Single Pole Single hrow $SPS% "#is type of relay #as a total of four terminals. Out oft#ese t'o terminals can $e connected or disconnected. "#e ot#er t'o terminals are needed

for t#e coil.

Single Pole Do&'le hrow $SPD% "#is type of a relay #as a total of five terminals. Out

f t#ese t'o are t#e coil terminals. A common terminal is also included '#ic# connects to

eit#er of t'o ot#ers.

Do&'le Pole Single hrow $DPS% "#is relay #as a total of si, terminals. "#ese

terminals are furt#er divided into t'o pairs. "#us t#ey can act as t'o 66";s '#ic# are

actuated $y a single coil. Out of t#e si, terminals t'o of t#em are coil terminals.

Do&'le Pole Do&'le hrow $DPD% "#is is t#e $iggest of all. 9t #as mainly eig#t relayterminals. Out of t#ese t'o ro's are designed to $e c#ange over terminals. "#ey are

designed to act as t'o 6D" relays '#ic# are actuated $y a single coil.
http://science.howstuffworks.com/electromagnet.htmhttp://science.howstuffworks.com/electromagnet.htm


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How it works ?

How it works ?

Hand drill

9t is useful tool for 'ood'or%ers and t#ose '#o prefer not to use po'er tools.

1or%ing:

A #and drill is a manual tool t#at converts and amplifies circular motion of t#e cran%

into circular motion of a drill c#uc%. "#oug# it #as $een replaced in most

applications $y po'er drills& t#e #and drill is used $y many 'ood'or%ers.

"#e #and drill consists of a cran%ing #andle t#at turns pinion gears on t#e main s#aft.A c#uc% at t#e end of t#e s#aft #olds a drill $it. "#e opposite end of t#e s#aft #as a

second #andle t#at is #eld stationary '#ile t#e c#uc% turns. "#e drill $it is selected to

cut a #ole of a specific 'idt#& suc# as /e typically is inscri$ed on t#e

$it?s s#aft.


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How it works ?

Inno#ation "u$

8esign is not 2ust what it looks like and feels

like. esign is how it works.9

Ste#e;o$s


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How it works ?

How it works ?

!lectric Iron

In automatic type of electric iron, the pressure plate has a rectangular or

circular hole for locating the thermostat.

"orking

When a current is passed through the heating element which is placed

$etween the sole plate and pressure plate, the element gets heated up and

transfers its heat to the sole plate through conduction and in*turn the sole

plate also gets heated up.


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How it works ?temperature, a thermostat is used along with pilot lamp which ser#es as an

indicator

How it works ?

#!D1 light*emitting diode #!D- is a two*lead semiconductor light source. It is a

$asic pn*2unction diode, which emits light when acti#ated. When a tting

#oltage is applied to the leads, electrons are a$le to recom$ine with electron

holes within the de#ice, releasing energy in the form of photons.


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How it works ?

Sym$ol of (>

How it works ?

$use :-

Wires get hot when electricity tra#els through them. That)s how

ordinary, incandescent lamps work. >lectricity 'ows through a #ery

thin wire called a lament making it so hot that it gi#es o% light.

1 fuse is e0actly the same. It)s a thin piece of wire designed to carry

a limited electrical current. If you try to pass a higher current

through the wire, it)ll heat up so much that it $urns or melts. When

it melts, it $reaks the circuit it)s tted to and stops the current

'owing.

More recent fuse$o0es ha#e replacea$le cartridge fuses with thefuse wire $uilt into a glass cylinder that you can easily snap in and

Working #rinci#le +lectroluminescence

(nvented Oleg @osev(B7)

ames R. 4iard()

8ic% 2olonya%(B)

)irst #rod&ction
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How it works ?out. The latest fuse$o0es do away with fuses altogether and ha#e

trip switches instead. If a fault occurs, the fuse$o0 detects the

pro$lem instantly and the trip switch automatically switches o%

whiche#er circuits are a%ected.

How it works ?

%C& ( %iniature Circuit &reaker ) :-

Inside:

?rinciple :- An MCB functions by interrupting the continuity of electrical flow through the

circuit once a fault is detected. In simple terms MCB is a switch which automatically turnsoff when the current flowing through it passes the maximum allowable limit. Generally


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How it works ?MCB are designed to protect against oer current and oer temperature faults !oer

heating".

#here are two contacts one is fixed and the other moeable. $hen the current exceeds

the predefined limit a solenoid forces the moeable contact to open !i.e.% disconnect from

the fixed contact" and the MCB turns off thereby stopping the current to flow in the circuit.

In order to restart the flow of current the MCB is manually turned on. #his mechanism is

used to protect from the faults arising due to oer current or oer load.

#o protect against fault arising due to oer heating or increase in temperature a bi-metallic

strip is used. MCBs are generally designed to trip within &.' millisecond when an oer

current fault arises. In case of temperature rise or oer heating it may ta(e & seconds to &

minutes for the MCB to trip.

"u$e lig#t ( Eluorescent lamps )

"ypes : "'o types of fluorescent lamps:- 2ot Cat#ode F Cold Cat#ode

Eluorescent lamps 'or% $y ioni>ing mercury vapor in a glass tu$e. "#is causes

electrons in t#e gas to emit p#otons at GH freuencies. "#e GH lig#t is convertedinto standard visi$le lig#t using a p#osp#or coating on t#e inside of t#e tu$e.

"#e most common fluorescent lamp is t#e #ot cat#ode:

arts:

"#is lamp consists of a glass tu$e filled 'it# an inert gas (usually argon) at lo'

pressure. On eac# side of t#e tu$e you 'ill find a tungsten electrode. "#e $allast

regulates AC po'er to t#e electrodes. Older lamps used a starter to get t#e lamp

going. Modern lamps use pulse start '#ic# is done $y components 'it#in t#e $allast.

1or%ing


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How it works ?.) AC electric current passes t#roug# t#e $allast. "#e $allast 'ill step up t#e voltage

and ne,t t#e po'er passed t#roug# a ?c#o%e? or ?reactor?. All arc disc#arge lamps need

a c#o%e to limit current.

B.) "#e lamp?s glass tu$e is called a disc#arge tu$e and it 'or%s $y #aving electrons

pass from one electrode to t#e ot#er. "#is forms '#at is called an IarcI.

/.)"o get t#e lamp started you need a spi%e of #ig# voltage to get t#e arc started.

Holtage ?forces? current t#roug# t#e argon gas.6ince creating a #ig# voltage is a

c#allenge and dangerous& engineers figured out 'ays to ?pre#eat? t#e lamp& t#at 'ay

less of a #ig# voltage is reuired.

Gse a 6tarter (starts'itc#) - "#is met#od is t#e first and argua$ly t#e most relia$le

type of 'ay to start a lamp according to some. Many facilities still #ave older fi,tures'it# starting s'itc# pre#eat fluorescents.

"#tical Mo&se

An optical computer mouse uses a lig#t source& typically a lig#t-emitting diode& and a

lig#t detector& suc# as an array of p#otodiodes or an image sensor& to detect

movement relative to a surface.

9nside an optical computer mouse

2ere?s t#e inside of a typical optical mouse and a fe' of t#e main components. "#e

most interesting $its are in t#e center ('#ere t#e @+D lig#t s#ines do'n onto your

des%) and at t#e front ('#ere $utton presses are detected $y s'itc#es):

. An @+D at t#e $ac% generates red lig#t and s#ines it #ori>ontally& from t#e $ac% of t#e

mouse to'ard t#e front (from t#e left to t#e rig#t of t#is p#oto).


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How it works ?B. A plastic prism $ends (refracts) t#e lig#t from t#e @+D at an angle& do'n onto t#e des%.

/. A lig#t-detector c#ip measures lig#t reflected $ac% up from t#e des%& converting t#e analog

movements of your #and into digital signals t#at can $e sent to your computer.

J. "#e scroll '#eel at t#e front of t#e mouse is mounted on a s'itc# mec#anism t#at detects

$ot# #o' muc# it?s rotated and '#et#er you?ve pressed it (it functions li%e t#e central $utton

of a conventional mouse). Rotations of t#e scroll '#eel can $e detected in a variety of

different 'ays. 6ome mice use potentiometers ($roadly& varia$le resistors)& similar to t#e

volume control on a radio $ut a$le to turn around multiple times. Ot#ers use various %inds

of rotary s'itc#es oroptical (rotary) encodersto convert analog'#eel movements to digital

signals.

. A micros'itc# detects '#en you press t#e rig#t mouse $utton. "#ere?s an identical s'itc#

on t#e ot#er side to detect t#e left mouse $utton.

. "#e G64ca$le connection carries digital information from t#e mouse to your computer.

>lectric Bell

The function of an electric $ell relies on two things: the

opening and closing of a circuit and an electromagnet.

Working:*
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How it works ?When power is running through the electric $ell)s circuit, an

electromagnet draws a mounted metal clapper towards the

$ell, striking it. "owe#er, when the clapper is pulled $y the

electromagnet, it $reaks the $ell)s circuit.


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How it works ?

The technologically superior electronic regulators o#ercome these

pro$lems $y using electronic components to control the speed ofthe fan.

Some of the ad#antages of electronic fan regulators are:

. They pro#ide a continuous speed control.

3. ?ower sa#ing at all the speeds.

4. Smaller si5e and weight.

The heart of the electronic fan regulator is T@I1!. T@I1! is asemiconductor de#ice $elonging to the family of thyristors.

Touch Screen

Touch*screen monitors ha#e $ecome more and more commonplace as theirprice has steadily dropped o#er the past decade. There are three $asicsystems that are used to recogni5e a person)s touch:

&@esisti#e &!apaciti#e


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How it works ?The resisti#e system consists of a normal glass panel that is co#ered with aconducti#e and a resisti#e metallic layer. These two layers are held apart $yspacers, and a scratch*resistant layer is placed on top of the whole setup. 1nelectrical current runs through the two layers while the monitor is operational.

When a user touches the screen, the two layers make contact in that e0actspot. The change in the electrical eld is noted and the coordinates of the pointof contact are calculated $y the computer. Ance the coordinates are known, aspecial dri#er translates the touch into something that the operating systemcan understand, much as a computer mouse dri#er translates a mouse)smo#ements into a click or a drag.

&@esisti#e &!apaciti#e

In the capaciti#e system, a layer that stores electrical charge is placedon the glass panel of the monitor. When a user touches the monitor with his orher nger, some of the charge is transferred to the user, so the charge on thecapaciti#e layer decreases. This decrease is measured in circuits located ateach corner of the monitor. The computer calculates, from the relati#edi%erences in charge at each corner, e0actly where the touch e#ent took placeand then relays that information to the touch*screen dri#er software. Ane

ad#antage that the capaciti#e system has o#er the resisti#e system is that ittransmits almost C percent of the light from the monitor, whereas theresisti#e system only transmits a$out D7 percent. This gi#es the capaciti#esystem a much clearer picture than the.resisti#e.system.


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How it works ?

Stapler

Working:*The staples are loaded into maga5ine so that two points

face towards the $ase of the stapler. The spring creates tension

that pushes the staples toward the front of the stapler. When

pressure is applied to the head of the stapler, the maga5ine

pushes down on the paper, and a metal plate in the head of the

stapler pushes the front staple down the maga5ine. The two

points are forced into the paper, piercing the pages until they

come into contact with the an#il. There is a cur#ed groo#e

in the an#il. The ends of the staple are forced into this groo#e, where the

pressure forces them to end. They $end inwards, creating a lock around the

pages.

A stapler worksby using force to pusha staple through thepaper, then secure thepages together.

There are eightsignicant parts thatcome together to makethis happen, as labeledin the diagram above.First, the stapler itselfis composed mainly ofthe Head and thebase .Connected to thehead is the aga!ine ,which holds the staples.The head is connectedto the base by a hangar, which is soldered inplace. The pin at the

back of the staplerallows the head toswing up and down toload staples or in somemodels open upcompletely for use intacking items. "nsidethere are springs thathave two purposes.#ne spring pushes thestaples down the

maga!ine to reload thestapler. The otherworks to pull thestapler head back upafter it has stapled adocument. #n the base,there is an anvil , which

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Working of daily household devices