water level controoler

8/13/2019 Water Level Controoler

1/27

OF

WATER LEVER CONTROLLER


2/27

INTRODUCTION

Water is the most important Natures gift to the mankind. Without this

there is no life. Now the man understands its importance especially there

where is not available easily. It is now being managed by the proper manner

in city areas where the use of it is more than its availability. Water Level

Controller as clear from it is the top level of the overhead tanks in houses or

in industrial areas. his is a basic circuit used in all water level indicators.

!ere is a simple but effective pro"ect which can control the storage level of

water in a tank to provide water throughout the day. he circuit re#uires a

few components and can be constructed in a couple of hours. It is wired

around two readily available npn transistor which drive relay $L%& when the

water level falls below a predetermined level.


3/27

CIRCUIT WORKING

It is wired around two readily available npn transistor which drive

relay $L%& when the water level falls below a predetermined level. 'ssume

that the tank is filled with water up to level '. the base of transistor & is

held at a positive potential through suspended metallic rod which is

connected to (&)*. he voltage developed across resistor $) is sufficient to

hold transistor & in saturation. he base of & is held at a positive potential

via level + also through N,C contact of the relay. $L& is employed to switch

the power supply to the pumping motor on or off. 's long as & conducts

the voltage at its collector with respect to ground is practically -ero and

hence transistor ) does not conduct.

When water falls below level ' & continues to conduct via level +.

+ut when it falls below level + base "unction of & is reverse biased and

voltage at the collector of & is around (&)* with respect to ground. hus

transistor ) conducts in the saturation region and activates the relay.

Now the motor gets connected to its power supply via the N,/

contacts 0which are now closed1 of the relay. 't the same time another pair

of relay contacts disconnects level + and resistor $&. 2o when water

reaches level + transistor & still does not conduct and the water level

continues to rise till level '. when water touches level ' & is forwardbiased the relay is de%energised and the power supply of the motor is cut

off. 't the same time another pair of relay contacts connects level + and

resistor $& via its N,C state. Capacitor C& provides a momentary time%delay

start. L34 indicates that the tank is being filled with three level.


4/27

POWER SUPPLY

NEED OF POWER SUPPLY:-

5erhaps all of you are aware that a power supply is a primary

re#uirement for the test bench of a home e6perimenters mini lab. ' battery

eliminator can eliminate or replace the batteries of solid%state electronic

e#uipment and ))7* '.C. mains instead of the batteries or dry cells thus can

operate the e#uipment. Nowadays the sued of commercial battery eliminator

or power supply unit have become increasingly popular as power source for

household appliances like transceiver record player clock etc.

Summary of powr !upp"y #$r#u$% fa%ur!:-

&r$f '!#r$p%$o( of opra%$o(:gives out well regulated

(8* output output current capability of 977m'.

C$r#u$% pro%#%$o(: +uilt :in overheating protection shuts

down output when regulator IC gets too hot.

C$r#u$% #omp")$%y:simple and easy to build.

C$r#u$% prforma(#: 2table (8* output voltage reliable

/peration.

A*a$"a+$"$%y of #ompo((%!: 3asy to get uses only

common basic components.

D!$,( %!%$(,: +ased on datasheet e6ample circuit I have

used this circuit successfully as part of other electronics pro"ects.

App"$#a%$o(!:part of electronics devices small laboratory

power supply.


5/27

DESCRITION OF POWER SUPPLY

his circuit is a small ( 8 volts power supply. Which is useful when

e6perimenting with digital electronics. 2mall ine6pensive battery with

variable output voltage are available but usually their voltage regulation is

very poor which makes them not very usable for digital circuit e6perimenter

unless a better regulation can be achieved in some way. he following

circuit is the answer to the problem.his circuit can give (8* output at about 977m' current. he circuit

has overload and terminal protection.

COPONENTS USED


6/27

SEICONDUCTOR:

0&1 & ) ;;.. N5N

0 04iode1

0=1L34

RESISTANCES:

0&1 $&$) ;; &7? /hm.

CAPACITOR:

0&1C& ;;;&77 @A4

0)1C) ;;. &777 @A4

ISCELLANEOUS:

$3L'B ;;;;; *

ransformer ;;;;. &)%7%&)


7/27

CIRCUIT DAIGRA


8/27

RESISTOR

' resistor is an electrical component that limits or regulates the flow of

electrical current in an electronic circuit. $esistors can also be used to

provide a specific voltagefor an active device such as a transistor.

'll other factors being e#ual in a direct%current 04C1 circuit the current

through a resistor is inversely proportional to its resistance and directly

proportional to the voltage across it. his is the well%known /hmDs Law. In

alternating%current 0'C1 circuits this rule also applies as long as the resistor

does not contain inductance or capacitance.

$esistors can be fabricated in a variety of ways. he most common type in

electronic devices and systems is the carbon-composition resistor. Aine

granulated carbon 0graphite1 is mi6ed with clay and hardened. he resistancedepends on the proportion of carbon to clayE the higher this ratio the lower

the resistance.

'nother type of resistor is made from winding Nichrome or similar wire on

an insulating form. his component called a wirewound resistor is able to

handle higher currents than a carbon%composition resistor of the same

physical si-e. !owever because the wire is wound into a coil the

component acts as an inductors as well as e6hibiting resistance. his does

not affect performance in 4C circuits but can have an adverse effect in 'Ccircuits because inductance renders the device sensitive to changes in output.
http://searchcio-midmarket.techtarget.com/sDefinition/0,,sid183_gci211871,00.htmlhttp://searchcio-midmarket.techtarget.com/sDefinition/0,,sid183_gci213320,00.htmlhttp://searchcio-midmarket.techtarget.com/sDefinition/0,,sid183_gci213216,00.htmlhttp://searchcio-midmarket.techtarget.com/sDefinition/0,,sid183_gci213659,00.htmlhttp://searchcio-midmarket.techtarget.com/sDefinition/0,,sid183_gci212894,00.htmlhttp://searchcio-midmarket.techtarget.com/sDefinition/0,,sid183_gci212695,00.htmlhttp://whatis.techtarget.com/definition/0,,sid9_gci213754,00.htmlhttp://searchcio-midmarket.techtarget.com/sDefinition/0,,sid183_gci212339,00.htmlhttp://searchcio-midmarket.techtarget.com/sDefinition/0,,sid183_gci211871,00.htmlhttp://searchcio-midmarket.techtarget.com/sDefinition/0,,sid183_gci213320,00.htmlhttp://searchcio-midmarket.techtarget.com/sDefinition/0,,sid183_gci213216,00.htmlhttp://searchcio-midmarket.techtarget.com/sDefinition/0,,sid183_gci213659,00.htmlhttp://searchcio-midmarket.techtarget.com/sDefinition/0,,sid183_gci212894,00.htmlhttp://searchcio-midmarket.techtarget.com/sDefinition/0,,sid183_gci212695,00.htmlhttp://whatis.techtarget.com/definition/0,,sid9_gci213754,00.htmlhttp://searchcio-midmarket.techtarget.com/sDefinition/0,,sid183_gci212339,00.html


9/27

RESISTOR COLOUR CODE


10/27

CAPACITOR

' capacitor is a tool consisting of two conductive plates each of which hosts an

opposite charge. hese plates are separated by a dielectric or other form of

insulator which helps them maintain an electric charge. here are several types ofinsulators used in capacitors. 36amples include ceramic polyester tantalum air

andpolystyrene. /ther common capacitor insulators include air paper and plastic.

3ach effectively prevents the plates from touching each other.

' capacitor is often used to store analogue signals and digital data. 'nother type of

capacitor is used in the telecommunications e#uipment industry. his type of

capacitor is able to ad"ust the fre#uency and tuning of telecommunications

e#uipment and is often referred to a variable capacitor. ' capacitor is also ideal

for storing an electron. ' capacitor cannot however make electrons.

SY&OL

SY&OL OF ELECTROLYTIC CAPACITOR

' capacitor measures in voltage which differs on each of the two interior plates.

+oth plates of the capacitor are charged but the current flows in opposite

directions. ' capacitor contains &.9 volts which is the same voltage found in a

common '' battery. 's voltage is used in a capacitor one of the two plates

becomes filled with a steady flow of current. 't the same time the current flows

away from the other plate.

o understand the flow of voltage in a capacitor it is helpful to look at naturally

occurring e6amples. Lightning for e6ample is similar to a capacitor. he cloud

represents one of the plates and the ground represents the other. he lightning is

the charging factor moving between the ground and the cloud.
http://www.wisegeek.com/what-is-polyester.htmhttp://www.wisegeek.com/what-is-tantalum.htmhttp://www.wisegeek.com/what-is-polystyrene.htmhttp://www.wisegeek.com/what-is-telecommunications.htmhttp://www.wisegeek.com/what-is-an-electron.htmhttp://www.wisegeek.com/what-is-lightning.htmhttp://www.wisegeek.com/what-is-polyester.htmhttp://www.wisegeek.com/what-is-tantalum.htmhttp://www.wisegeek.com/what-is-polystyrene.htmhttp://www.wisegeek.com/what-is-telecommunications.htmhttp://www.wisegeek.com/what-is-an-electron.htmhttp://www.wisegeek.com/what-is-lightning.htm


11/27

IAGE OF ELECTROLYTIC CAPACITOR

TRANSISTORS

' Tra(!$!%oris an !m$#o('u#%orwhich is a fundamental component in almost

all electronic devices. ransistors are often said to be the most significant invention

of the )7th Century. ransistors have many uses including switching

voltage,current regulation and amplification % all of which are useful in r(wa+"

(r,y applications.

' transistor controls a large electrical output signal with changes to a small input

signal. his is analogous to the small amount of effort re#uired to open a tap

0faucet1 to release a large flow of water. 2ince a large amount of current can be

controlled by a small amount of current a transistor acts as an amp"$f$r.

' transistor acts as a !w$%#.which can open and close many times per second.

&$po"ar /u(#%$o( Tra(!$!%or!

he most common type of transistor is a +$po"ar 0u(#%$o( %ra(!$!%or. his is made

up of three layers of a semi%conductor material in a sandwich. In one configuration

the outer two layers have e6tra electrons and the middle layer has electrons

missing 0holes1. In the other configuration the two outer layers have the holes and

the middle layer has the e6tra electrons.


12/27

SY&OL OF NPN 1 PNP TRANSISTOR

Layers with e6tra electrons are called N-Typ those with electrons missing called

P-Typ. herefore the bipolar "unction transistors are more commonly known as

PNP %ra(!$!%or! and NPN %ra(!$!%or! respectively.

+ipolar "unction transistors are typically made of !$"$#o( and so they are very

cheap to produce and purchase.

2ow 'o Tra(!$!%or! Wor3

' bipolar "unction transistor has three terminals % &a! Co""#%or and Em$%%r


13/27

corresponding to the three semi%conductor layers of the transistor. he weak input

current is applied to the inner 0base1 layer. When there is a small change in the

current or voltage at the inner semiconductor layer 0base1 a rapid and far larger

change in current takes place throughout the whole transistor.

5ictured above is a schematic diagram of the more common NPN %ra(!$!%or.+elow is an illustration of the same transistor using water rather than electricity to

illustrate the way it functionsF

he illustration shows pipe work with three openings & 4&a!56 C4Co""#%or56 a('

E 4Em$%%r57he reservoir of water at C is the supply voltagewhich is prevented

from getting though to 3 by a plunger. If water is poured into + it pushes up the

plunger letting lots of water flow from C to 3. If even more water is poured into +

the plunger moves higher and the flow of water from C to 3 increases.

herefore a small input current of electricity to the +ase leads to a large flow of

electricity from the Collector to the 3mitter.

Tra(!$!%or Ga$(

Looking at the water analogy again if it takes & litre of water per minute poured

into + to control &77 litres of water per minute flowing from C to 3 then the Ga$(

0or amp"$f$#a%$o( fa#%or1 is &77. ' real transistor with a gain of &77 can control


14/27

&77m' of current from C to 3 with an input current of "ust &m' to the base 0+1.

If the output power 0current 6 voltage1 are more than & Watt a Powr Tra(!$!%or

must be used. hese let much more power flow through and re#uire a larger

controlling input current.

DIODES

' '$o' is the simplest sort of semiconductor device. +roadly speaking a

semiconductor is a material with a varying ability to conduct electrical current.

@ost semiconductors are made of a poor conductor that has had $mpur$%$!0atoms

of another material1 added to it. he process of adding impurities is called 'op$(,.

SY&OL OF DIODE

Circuit 2ymbol
http://electronics.howstuffworks.com/diode.htmhttp://electronics.howstuffworks.com/atom.htmhttp://electronics.howstuffworks.com/diode.htmhttp://electronics.howstuffworks.com/atom.htm


15/27


16/27

A% %. 0u(#%$o(6 fr "#%ro(! from %. N-%yp ma%r$a" f$"" .o"!

from %. P-%yp ma%r$a"7 T.$! #ra%! a( $(!u"a%$(, "ayr $( %.

m$''" of %. '$o' #a""' %. 'p"%$o( 8o(7

o get rid of the depletion -one you have to get electrons moving from the N%type

area to the 5%type area and holes moving in the reverse direction. o do this you

connect the N%type side of the diode to the negative end of a circuit and the 5%type

side to the positive end. he free electrons in the N%type material are repelled by

the negative electrode and drawn to the positive electrode. he holes in the 5%typematerial move the other way. When the voltage difference between the electrodes

is high enough the electrons in the depletion -one are boosted out of their holes

and begin moving freely again. he depletion -one disappears and charge moves

across the diode.


17/27

W.( %. (,a%$* (' of %. #$r#u$% $! .oo3' up %o %. N-%yp "ayr a('

%. po!$%$* (' $! .oo3' up %o P-%yp "ayr6 "#%ro(! a(' .o"! !%ar%mo*$(, a(' %. 'p"%$o( 8o( '$!appar!7

If you try to run current the other way with the 5%type side connected to the

negative end of the circuit and the N%type side connected to the positive end

current will not flow. he negative electrons in the N%type material are attracted to

the positive electrode. he positive holes in the 5%type material are attracted to the

negative electrode. No current flows across the "unction because the holes and the

electrons are each moving in the wrong direction. he depletion -one increases.02ee !ow 2emiconductors Workfor more information on the entire process.1

W.( %. po!$%$* (' of %. #$r#u$% $! .oo3' up %o %. N-%yp "ayr
http://electronics.howstuffworks.com/diode.htmhttp://electronics.howstuffworks.com/diode.htm


18/27

a(' %. (,a%$* (' $! .oo3' up %o %. P-%yp "ayr6 fr "#%ro(!

#o""#% o( o( (' of %. '$o' a(' .o"! #o""#% o( %. o%.r7 T.

'p"%$o( 8o( ,%! +$,,r7

DIODES C2ARACTERISTICS

LED

' light%emitting diode 0L341 is a semiconductordevice that emits visible lightwhen an electric currentpasses through it. he light is not particularly bright but

in most L34s it is monochromatic occurring at a single wavelength. he output

from an L34 can range from red 0at a wavelength of appro6imately >77

nanometers1 to blue%violet 0about =77 nanometers1. 2ome L34s emit infrared 0 I$1

energy 08


19/27

SY&OL OF LED

Circuit 2ymbol

&(f$%! of LED!

Low powr r9u$rm(%F @ost types can be operated with battery power

supplies.

2$,. ff$#$(#y: @ost of the power supplied to an L34 or I$34 is

converted into radiation in the desired form with minimal heat production.

Lo(, "$f: When properly installed an L34 or I$34 can function for

decades.

Typ$#a" App"$#a%$o(!

I('$#a%or "$,.%!: hese can be two%state 0i.e. on,off1 bar%graph oralphabetic%numeric readouts.

LCD pa(" +a#3"$,.%$(,:2peciali-ed white L34s are used in flat%panel

computer displays.

F$+r op%$# 'a%a %ra(!m$!!$o(: 3ase of modulation allows wide

communicationsbandwidthwith minimal noise resulting in high speed and

accuracy.

Rmo% #o(%ro": @ost home%entertainment HremotesH use I$34s to

transmit data to the main unit.

op%o$!o"a%or: 2tages in an electronic system can be connected together

without unwanted interaction.
http://searchcio-midmarket.techtarget.com/sDefinition/0,,sid183_gci214075,00.htmlhttp://searchnetworking.techtarget.com/sDefinition/0,,sid7_gci212586,00.htmlhttp://searchnetworking.techtarget.com/sDefinition/0,,sid7_gci211634,00.htmlhttp://searchnetworking.techtarget.com/sDefinition/0,,sid7_gci213614,00.htmlhttp://searchcio-midmarket.techtarget.com/sDefinition/0,,sid183_gci214075,00.htmlhttp://searchnetworking.techtarget.com/sDefinition/0,,sid7_gci212586,00.htmlhttp://searchnetworking.techtarget.com/sDefinition/0,,sid7_gci211634,00.htmlhttp://searchnetworking.techtarget.com/sDefinition/0,,sid7_gci213614,00.html


20/27

IAGE OF DIFFERENT LEDS

Tra(!formr

W.a% $! a Tra(!formr;

' transformer transfers electrical energy between two circuits. It usually consists

of two wire coils wrapped around a core. hese coils are called primary and

secondary windings. 3nergy is transferred by mutual induction caused by a

changing electromagnetic field. If the coils have different number of turns aroundthe core the voltage induced in the secondary coil will be different to the first.

ransformers convert 'C electricity from one voltage to another with little loss of

power. ransformers work only with 'C and this is one of the reasons why mains

electricity is 'C.

2tep%up transformers increase voltage step%down transformers reduce voltage.

@ost power supplies use a step%down transformer to reduce the dangerously high

mains voltage 0)


21/27

ransformers waste very little power so the power out is 0almost1 e#ual to the

power in. Note that as voltage is stepped down current is stepped up.

he ratio of the number of turns on each coil called the %ur(! ra%$o determines

the ratio of the voltages. ' step%down transformer has a large number of turns on

its primary 0input1 coil which is connected to the high voltage mains supply and a

small number of turns on its secondary 0output1 coil to give a low output voltage.

2ymbol of transformer

Tra(!formr

2ow 'o! a Tra(!formr Wor3

'lternating current in the primary winding creates an electromagnetic field that

induces a current in the secondary winding when the field changes. 2mall

transformers use enameled wire for their windings while large transformers use

insulated copper strips. ransformers can be single winding center%tap or multi%

tap. Center%taps have a terminal at the middle point of the secondary winding

which has half the voltage of the end terminal. @ulti%taps have many terminals

along the winding whose voltages depend on their locations. he purpose of the

core is to direct the electromagnetic field through the secondary winding. 2ilicon


22/27

steel cores are used for their high magnetic permeability. he insulated laminations

work better than solid cores by confining eddy currents which reduces their

losses.

U!! of Tra(!formr!ransformers are mainly used to convert one voltage to another. he process of

increasing the voltage is called Jstepping upK while decreasing the voltage is

called Jstepping downK. @ost electronic e#uipments need a transformer to lower

the mains voltage to a usable level. ransformers are also found in power adapters

and battery chargers. Inverters are transformers which step%up a low voltage to a

higher voltage allowing a mains powered e#uipment to run on a battery.

'dditional circuitry is re#uired to change the batteryDs direct current into

alternating current. ransformers are used for electricity distribution to minimi-e

energy loss over long distances. !igher voltages allow for lower currents whichreduces the losses caused by resistance.

RELAY

' relay is an "#%r$#a""y opra%' !w$%#.. Current flowing through the coil of the

relay creates a magnetic field which attracts a lever and changes the switch

contacts. he coil current can be on or off so relays have two switch positions and

they are 'ou+" %.row0#.a(,o*r1 switches.

$elays allow one circuit to switch a second circuit which can be completely

separate from the first. Aor e6ample a low voltage battery circuit can use a relay to

switch a )


23/27

$elays are usuallly 254 or 454 but they can have many more sets of switch

contacts for e6ample relays with = sets of changeover contacts are readily

available. Aor further information about switch contacts and the terms used to

describe them please see the page on switches.

@ost relays are designed for 5C+ mounting but you can solder wires directly tothe pins providing you take care to avoid melting the plastic case of the relay.

he supplierDs catalogue should show you the relayDs connections. he coil will be

obvious and it may be connected either way round. $elay coils produce brief high

voltage DspikesD when they are switched off and this can destroy transistors and ICs

in the circuit. o prevent damage you must connect aprotection diodeacross the

relay coil.

he animated picture shows a working relay with its coil and switch contacts. Bou

can see a lever on the left being attracted by magnetism when the coil is switchedon. his lever moves the switch contacts. here is one set of contacts 02541 in

the foreground and another behind them making the relay 454.

he relayDs switch connections are usually labelled C/@ NC and N/F

CO Common always connect to this it is the moving part of the switch.

NC Normally Closed C/@ is connected to this when the relay coil is off.

NO Normally /pen C/@ is connected to this when the relay coil is o(. Connect to C/@ and N/ if you want the switched circuit to be o( w.( %.

r"ay #o$" $! o(.

Connect to C/@ and NC if you want the switched circuit to be o( w.( %.

r"ay #o$" $! off.

A'*a(%a,! of r"ay!:
http://www.kpsec.freeuk.com/components/switch.htmhttp://www.kpsec.freeuk.com/components/relay.htm#protect%23protecthttp://www.kpsec.freeuk.com/components/switch.htmhttp://www.kpsec.freeuk.com/components/relay.htm#protect%23protect


24/27

$elays can switch AC a(' DC transistors can only switch 4C.

$elays can switch .$,. *o"%a,! transistors cannot.

$elays are a better choice for switching "ar, #urr(%!0M 9'1.

$elays can switch ma(y #o(%a#%!at once.

D$!a'*a(%a,! of r"ay!: $elays are +u"3$rthan transistors for switching small currents.

$elays #a((o% !w$%#. rap$'"y0e6cept reed relays1 transistors can switch

many times per second.

$elays u! mor powrdue to the current flowing through their coil.

$elays r9u$r mor #urr(% %.a( ma(y IC! #a( pro*$' so a low power

transistor may be needed to switch the current for the relayDs coil.

SOLDERING TEC2NI


25/27

5reparing the soldering ironF

Wipe the tip clean on the wetted sponge provided.

+ring the resin cored solder to the iron and tin the tip of the iron.

Wipe the e6cess solder of the tip using the wet sponge.

$epeat until the tip is properly tinned.


26/27

SOLDERING COPONENTS INTO T2E PC&

+end the component leads at right angles with both bends at the same

distance apart as the 5C+ pad holes.

3nsure that both component leads and the copper 5C+ pads are clean and

free of o6idi-ation.

Insert component leads into holes and bend leads at about


27/27

PRECAUTIONS

&. @ount the components at the approp places before soldering. Aollow the

circuit discription and components details leads identification etc. 4o not

start soldering before making it confirm that all the components are

mounted at the right place.

). 4o not use a spread solder on the board it may cause short circuit.

water level controoler

Documents