Basic Electrik
-
Upload
mohdshafikbinhamzah -
Category
Documents
-
view
223 -
download
0
Transcript of Basic Electrik
-
8/6/2019 Basic Electrik
1/108
Basic
Electricity
-
8/6/2019 Basic Electrik
2/108
MaterialMaterial
Substance Element Atom
Fundamental of material
-
8/6/2019 Basic Electrik
3/108
Occurrence of electricityOccurrence of electricity
Material Molecule Atom Atomic nucleus Nucleus
Proton
Electron
What is electricity?
-
8/6/2019 Basic Electrik
4/108
Occurrence of electricityOccurrence of electricity
Electron Nucleus
Shell
Electrons
Protons
Neutron
++
+
-
Electrons
Structure of Atom Detail str ucture of Atom
Structure of Atom
-
8/6/2019 Basic Electrik
5/108
Occurrence of electricityOccurrence of electricityAtom ionpositive ion
Negative ion
Electrically Neutral
Positive Ion Negative Ion
-
8/6/2019 Basic Electrik
6/108
Occurrence of electricityOccurrence of electricityFree Electron Movement = Occurrence of electricity
+++
--
-
-
--
--
-
-
Fundamental question
-
8/6/2019 Basic Electrik
7/108
Current, Voltage, ResistanceCurrent, Voltage, Resistance
Current
Voltage
Resistance
-
8/6/2019 Basic Electrik
8/108
Current 1Current 1
Water tank A
(Positive terminal)
Water tank B
(Negative terminal)
Current
flow
Water level
difference
(Potential
difference)
Water
wheelrotate
Lamp
ON
Flowing of current is transfer of free electron .
When there is electrical potential
Current flow .
Electrical energy : Transfer
Amount of free electron .
If transfer track of free electron
Grows, big current passes .
If quantity of current big
Actuator's drive increase .
-
8/6/2019 Basic Electrik
9/108
Current 2Current 2
Tank A Tank B
Same waterlevel
No potential
Difference
No current
flow
No water
wheel
Rotate
Lamp
OFF
It is no stream of current that it is no transfer of free electron .
When there is no electrical
Potential, current not flow .
Electrical energy : Because it is no
Transfer of free electron, there is
no
Occurrence of energy
Because current does not flow
There is no actuator drive .
Because there is no electrical
Potential, cu
rrent does not flow .
-
8/6/2019 Basic Electrik
10/108
Current 2Current 2Current represent
The ampere is expressed using the letter I .
The ampere describes the rate of flow of electrons past any given point
In a circuit .
Current unit : A (Ampere)
1 Ampere : One ampere is equal to one coulomb of
Charge flowing Part a point in one second .
I = Q/T (Q : Coulomb, T : Second)
1 coulomb = 1/1.6012910-9 = 6.251018
Thus, The electric charge amount that pass per time
1 A : 1,000, 1 : 0.001 A, 1 : 1,000 A
-
8/6/2019 Basic Electrik
11/108
Potential and potential difference VS .Potential and potential difference VS .
CurrentCurrent
Water tank B
Low water level
Water current
Water tank A
High water level
Water level
Difference
(Potential
Difference)
Water wheel : ON
Water wheel work
Water Flow
No water current
Water tank A Water tank B
No water level
Difference(Potential same)
Water wheel : OFF
Water wheel does not work
No Water Flow
Current flowing
-
8/6/2019 Basic Electrik
12/108
Current FunctionCurrent Function3 function of current.
Heat function
Ex) cigar lighter, electric stove etc
Magnetism function
Ex) solenoid
Chemistry functionEx) battery
-
8/6/2019 Basic Electrik
13/108
Summary for currentSummary for current Flowing of current is transfer of electron .
If transfer of electron is much, mean that current passes much .
Though there is potential difference, current passes
When connected between high and low potential .
If transfer of free electron is much, heat generate
Therefore, electric wire bunt out that is done
Because so much current passed .
Quantity of current can explain by quantity of water
That pass a pipe .
Current passes much to some actuator means that amount
Of electric power is strong .
-
8/6/2019 Basic Electrik
14/108
VoltageVoltage
Voltage symbol : E
Voltage unit : V
E = W (joule)/Q (coulombs) Volt
W : Electric powerQ : Electric charge amount
1 volt : 0.001
1 volt : 1,000:
1 : 1,000 v
-
8/6/2019 Basic Electrik
15/108
Potential and potential differencePotential and potential difference
11
Water level
difference
(Potential
difference)Water level12(Potential)
Water level 0
(Ground)
Water tank A(Positive terminal)
Water tank B(Negative terminal)
Water current
(Electrical current)
Electrical Potential
When there is electrical potential between A and b, current flowing .
- Water tank A (positive potential) : 12
- Water tank B (Negative potential) : 0
-
8/6/2019 Basic Electrik
16/108
Potential & potential difference 2Potential & potential difference 2+(Positive)
12 Volt
BATTERY
A
B
C D
E
F
-(Negative)
Switch
Lamp
Voltage measure position Switch ON condition (Lamp ON) Switch OFF condition (Lamp ON)
A ~ B
B ~ C
C ~ D
D ~ E
E ~ F
F ~ A
C ~ E
C ~ F
D ~ F
-
8/6/2019 Basic Electrik
17/108
Potential & potential difference 3Potential & potential difference 3
FUSE F8
5A
C224
BATTERY
COMPARTMENT
FUSE BOX
# 1
0.5R/L
0.5R/L
0.5R/L
0.5 B
ROOM
LAMP
SWITCH
C40-1
C40-2
CR02
R25
R26
ROOM LAMP
G09
12 Volt
Battery
Battery earth
Battery +Battery -
To measure each position for voltage
-
8/6/2019 Basic Electrik
18/108
ResistanceResistance
The electric resistance in a material is changed
According to the following variables:
- Kind of material- Sectional area of wire
- Length of wire
- Temperature
-
8/6/2019 Basic Electrik
19/108
ResistanceResistance
Resistance relation formula
R = L S
R : Resistance of material
: An invariable by kind of material ( m)
L : Length of wire (m)
S : Sectional area ()
-
8/6/2019 Basic Electrik
20/108
Current, Voltage, and ResistanceCurrent, Voltage, and Resistance
relationrelation
Current : A measure of the amount of electron flow .
Like a water pipe, the larger the pipe the greater the capacity to carry flow .Measured in "Amperes", or "Amps" (A) .
Voltage : A measure of the potential of a source to supply electromotive force (EMF), or
Electrical pressure .
Measured in Volts (V) .
Resistance : A measure of the opposition to current flow in a circuit .
Measured in Ohms ()
P
P1 P2 Pascal Pb
Pump
Actuator
Pactator
-
8/6/2019 Basic Electrik
21/108
Current, Voltage, and ResistanceCurrent, Voltage, and Resistance
SummarySummaryCurrent
Voltage
Resistance
VoltageCurrent
Resistance
-
8/6/2019 Basic Electrik
22/108
Series circuit in BatterySeries circuit in Battery
Total battery voltage
1.5 volt
4 batteries = 6 volt
Total battery voltage
12 volt 2 batteries = 24 volt
Battery series connect
- Voltage : Increase
- Current : Equality
-
8/6/2019 Basic Electrik
23/108
Series circuit in CircuitSeries circuit in Circuit
R1 R2
I1 I2I
E : 12 Volt
R1 R2
I1 I2I
E:12 Volt
Lamp1 Lamp2
Direct circuit of equivalence------------------------ Direct circuit of 2 lamps
Characteristic of series connection in circuit .
At series connection of resistance, total resistance increases connect resistance .
Total resistance increases, flowing current decreases in circuit .
Flowing current is always same in series circuit even if measure in any place .
-
8/6/2019 Basic Electrik
24/108
Load in directLoad in direct--current circuitcurrent circuitCircuit with load in direct-current circuit
V = (R1 R0) I
Rtotal = R1 R0
R1 : Load (Resistance)
R0 : Wire line resistance
I = V (R1 R0)R1 R0
I
V
-
8/6/2019 Basic Electrik
25/108
o ca cu a e o en vo age oo ca cu a e o en vo age o
resistanceresistance
12 Volt
R1=1; R2=2; R3=;
E1=? v E2=?v E3=?v
2A1=2V 2A2=4V 2A3=6V
To calculate both end voltage of resistance in D.C circuit
Total resistance R = 1 2 3 = 6 Ohm
Current I = 12Volts 6Ohms = 2 Amp.
1 ) E 1 = I R1
12V = 2A 1 = 2 volt
2 ) E 2 = I R112V = 2A 2 = 4 volt
3) E3 = I R3
12V = 2A 3 = 6 volt
E total = E1 E2 E3
= 2volt 4volt 6volt
= 12 Volt
-
8/6/2019 Basic Electrik
26/108
easuremen or curren aneasuremen or curren an
voltagevoltage
V
+
-
Volt meter
+
-
Ampere meter
A
Voltage measurement in direct current circuit . Parallel connected voltage meter .
Voltage measurement in direct current circuit . Parallel connected voltage meter .
-
8/6/2019 Basic Electrik
27/108
ParallelParallel circuit in Batterycircuit in BatteryCharacteristic
Parallel connection ofbatteries
Voltage : Constant
Capacity ofbattery : Increase
-
8/6/2019 Basic Electrik
28/108
ParallelParallel CircuitCircuitCharacteristic
Parallel connect in connection of circuit
- As much as connect resistance in parallel circuit, total resistance
decreases.
- As much as connect resistance in parallel circuit, total current
increase.
R2E R1 I 1E1I 2E2
-
8/6/2019 Basic Electrik
29/108
a cu a e es s ance n ara ea cu a e es s ance n ara e
circuit 1circuit 1To calculate easily total resistance
Rtotal = Multiplication of total resistance Sum of total resistance
Rtotal = (R1 R2) (R1 + R2)
R2E R1I 1
E1I 2E2
-
8/6/2019 Basic Electrik
30/108
Calculate Current in ParallelCalculate Current in Parallel
circu
it 2circu
it 2A point cu
rrent = (I 1+I 2+I3) = B point c
urrent
Point C, D, E current : Current that each lamp consumes
Parallel equivalence circuit 3 lamp's parallel circuits
I
I1 sw1
I2 sw2
I3 sw3
A B
C
D
E
IR2
R3
I1
I2
I3E
E
R1
-
8/6/2019 Basic Electrik
31/108
SeriesSeries -- Parallel CircuitParallel CircuitTo Calculate :
Resistance
Current
Voltage
EE1
E2
R1 R2
I1 I2
I
R3
a
b
c
I
E1
E2
E
a
b
c
Rt R1&R2=(R1R2) / R1+R2
R3
I3 I3
-
8/6/2019 Basic Electrik
32/108
OhmOhms Laws Law
Any operating electrical circu
its mu
st have three factors,voltage, current, and resistance.
Their relationship can be described by Ohms Law statement.
Voltage(V) Current(I) Resistance(R)
UP UP SAME
SAME UP DOWN
SAME DOWN UP
-
8/6/2019 Basic Electrik
33/108
Ohms law formulaOhms law formula
To understand Ohms law formula
E = I R
I = E R
R = E I
E : Voltage
I : Current
R : Resistance
E
I R
Voltage
Current Resistance
-
8/6/2019 Basic Electrik
34/108
Determining Current in OhmDetermining Current in Ohmss
Law
Law
E = 12 volt
I = ?
R = 6 ;+
_
I = E / R
I = 12 volt / 6 ohms
I = 2 Amperes
E = 12 volt
I = ?
R = 1 2 ;
+
_
I = E / R
I = 12 volts / 12 ohms
I = 1 Amperes
when the resistance is doubled, the current is reduced to half its former value
Determining Current
-
8/6/2019 Basic Electrik
35/108
Determining Voltage & Resistance inDetermining Voltage & Resistance in
OhmOhms Laws Law
E = 12 volt
I = 3A
R = ? ;+
_
Determining Resistance
E = 12 volt
I = 3 ampere
R = ?
To calculate, divide 3 into
12 and the answer is 4;.
Determining Voltage
E = I R
E = 4 3
E = 12 volts
E = ? volt
I = 3A
R = 4 ;+
_
-
8/6/2019 Basic Electrik
36/108
Voltage Drop 1Voltage Drop 1 The voltage removed from the circuit by the load.
Load : Lamp, Actuator, or Resistance
The total voltage lost must equal the voltage applied.
E = 12 volt+
_
Impressed voltage = Voltage drop from actuator
12 volt
Switch
-
8/6/2019 Basic Electrik
37/108
Voltage Drop in CircuitVoltage Drop in Circuit
V2
Voltage
When switch ON 12 Volt in normality.
If lower than 12Volt, the lamp does not worknormality because it means that resistance
exists somewhere.
12VOLT
BATT.
SWITCH LAMP
V1
Voltage
when SW Off
= 12Voltwhen SW ON
=0 Volt
V4
12 volt
12
VOLT
G11
V1
8volt
V2
4volt
R1 R2
V3
SW ON :
0volt
SW Off :
12 Volt
ISW
G2
+
To understand voltage drop in equivalent circuit
Voltage Drop in Circuit
-
8/6/2019 Basic Electrik
38/108
KirchoffKirchoffs Law 1s Law 1(Current Law)(Current Law)Kirchoffs current law (Kirchoffs first law)
In circuit inflow current's sum and outflow sum of done current same .
Inflow current outflow current = 0
In this current flow below formula is formed in below circuit.
Formula
I1+I4(INPUT CURRENT) = I2+I3+I5(OUTPUT CURRENT)
I 1 = IN
I 5 = OUTI 2 = OUT
I 3 = OUTI 4 = IN
rc orc o s aw curren n c rcus aw curren n c rcu
-
8/6/2019 Basic Electrik
39/108
rc orc o s aw curren n c rcu s aw curren n c rcu
diagram.diagram.
R1 R2
I1 I2
E
I
In series circuit
I = ?
I = ( ) current,I1 = ( ) of R1
I2 = ( ) of R2
I
I 1
I 2
I 3
I 4
In parallel circuit
I = ?
I,I4 = ( ) current in circuit
I1 = ( ) oflamp1
I2 = ( ) oflamp2
I3 = ( ) of lamp
Kirchoffs current law
-
8/6/2019 Basic Electrik
40/108
KirchoffKirchoffs Law 2s Law 2 (Voltage Law)(Voltage Law)Kirchoffs voltage law (Kirchoffs second law)
Input source voltage Sum of voltage drop = 0
I
R1 R2
I1 I2
E1 E2
E1 = ( ) VoltE2 = ( ) Volt
E = ( ) Kirchoffs voltage law
E = ( )
= (R1I) + (R2 I)= (R1 + R2) I
-
8/6/2019 Basic Electrik
41/108
Electric power and WattElectric power and Watt
Amount of work that electricity during 1 second.
Amount ofelectrical energy, that consume during per time.
Expression of electric power : P
Unit of electric power : w(watt)
The formula for electric power is :
P(watt) = E(volt)
I(current) = E
E/R = E2
/R = E
E = P/I
I = P/E
-
8/6/2019 Basic Electrik
42/108
Summary for basicElectrical 1Summary for basicElectrical 1Troubleshooting method in circuit
M
A
B C
D
E
E
When switch on motor's operation is not smooth in below circuit,it explains checking method and inspection order.
Check procedure
1st. Measure the voltage of battery.
2nd, 1st. Measure the voltage of between B and C.
At this time, voltage must be 12 volts, and inspect following below order if is low than applied voltage.
And, if voltage are 12 volts, it is motor itself defect.
3rd, Measure the voltage between A and B
At this time, voltage bust be 0 volt, if higher than 0 volt, there is resistance between A and B.
4th, Measure the voltage between C and E
At this time, voltage bust be 0 volt, if higher than 0 volt, there is resistance between C and E.
-
8/6/2019 Basic Electrik
43/108
Summary for basicElectrical 2Summary for basicElectrical 2C
heck for grou
nd condition in Parallel circu
it
I
I1
I2
I3I 4
Switch1
Switch2
Switch3
VOLT
- Current I4 is different according to switch ON in above circuit diagram.
- And voltage V is different according to ground connection condition.
If it is normally, voltage V become 0volt
-
8/6/2019 Basic Electrik
44/108
Summary for basicElectrical 3Summary for basicElectrical 3Troubleshooting a series circuit
The voltmeter will now
read the amount ofvoltage drop across R1.
When the switch is closed,
the voltmeter will indicatezero volts across the switch.
12
VOLT
R2 SW
G11
I
G2
+
R1
12
VOLT
G11
R2I
G2
+
SWR1
With the switch open,
The voltmeter will read a full12-volt, the same as the source.
There is nothing volt
when the switch opened
V1V2
1. Measure voltage
2. Measure voltage
-
8/6/2019 Basic Electrik
45/108
Summary for basicElectrical 4Summary for basicElectrical 4Troubleshooting a parallel
Caution
The switch must be open or the power source disconnected when measuring
resistance using by ohmmeter.
Measure resistance 10;
Calculated resistance 5;
An ohmmeter can provide a quick idea about
the condition of the circuit.
An infinity reading would indicated an open, and
a zero resistance reading would indicate a short circuit.
12
VOLTR2=10;
I
Open
+
R1=10;
Switchopen
1. Measure resistance
-
8/6/2019 Basic Electrik
46/108
Summary for basicElectrical 5Summary for basicElectrical 5Troubleshooting a parallel
2. Measure current
An ammeter can be connected across the open switch,
It can measure the full load current of the circuit
The switch location of a circuit is an ideal location to connect an ammeter to the circuit.
R2
I
+
R1
Switch
-
8/6/2019 Basic Electrik
47/108
Summary for basicElectrical 6Summary for basicElectrical 6Troubleshooting series-parallel circuit
1. Measure voltage in series-parallel circuit
Measure voltage : 12 volt
12
VOLTR3G11
I
Open+
R2
Switch
R1
-
8/6/2019 Basic Electrik
48/108
Summary for basicElectrical 7Summary for basicElectrical 7Troubleshooting series-parallel circuit2. Measure current in series-parallel circuit
12
VOLTR3
G11
I
Open+
R2
Switch
R1
12
VOLT R3G11
I
Open
+
R2
SwitchR1
3. Measure resistance in series-parallel circuit
-
8/6/2019 Basic Electrik
49/108
Analog Multi meterAnalog Multi meter
N S
Very thin wire
Would on
Meter
Negative lead wirePositive lead wire
Indicate needle Spring
Scale
South field poleNorth field pole
Analog Multi Meter's operation principle
-
8/6/2019 Basic Electrik
50/108
Analog Current meterAnalog Current meterAn ammeter measures electrical current in a circuit.
M
R=100
R=11.1
0~1
0~10
0~50
0~100 R=1.04
R=1.01
Range Switch
-
8/6/2019 Basic Electrik
51/108
Analog Volt meterAnalog Volt meter
Analog voltmeter circuit
M
R=100
R=9.9 k
0~1
0~10
0~50
0~100R=99.9 k
R=499.9 k
0~500
R=900
Voltmeters are always connected in parallel with the device being measured
-
8/6/2019 Basic Electrik
52/108
Analog OhmmeterAnalog Ohmmeter
0
48
12
3 volt Battery
Black lead wireRed lead wire Resistor
Resistance scale
Zero AdjusterElectric
Magnetic
For Measure
Data indicate.
Ohmmeter circuit in case
-
8/6/2019 Basic Electrik
53/108
Characteristics ofAnalogCharacteristics ofAnalog
OhmmeterOhmmeterVoltage that important thing is measuring in resistance mode voltageoutput through lead wire are 3volt and 12volt according to ohm modeswitch position.
Range 1, 10, 1k : 3-volt output
Range10k : 12 volt(3volt+9volt) output
025
Polarity:+ Polarity:- Polarity:+Polarity:-
-
8/6/2019 Basic Electrik
54/108
DigitalmultiDigitalmulti--metersmeters
-
8/6/2019 Basic Electrik
55/108
Digital multiDigital multi--metersmeters SummarySummary
Summary for Analog multi meter When measure voltage, connect by parallel.
When measure current, connect by series connection.
Even if do not know measurement value, range establishment is
no necessity.
When there is selective switch to resistance mode, voltage is
output through probe.
- Ou
tpu
t voltage : 0.25 volt At this time, voltage output from read lead wire , and from
black lead wire - volt.
-
8/6/2019 Basic Electrik
56/108
Magnet and Magnetic ForceMagnet and Magnetic ForceCharacteristic of magnetic substance andM
agnetic line of force Magnetic line of force comes out from N pole and enter into S pole. Direction of magnetic line of force indicates the direction of the
magnetic field.
Density of magnetic line of force(Density of magnetic flux)indicates strength of magnetic field
Magnetic lines of force does not cross each other. If the direction of magnetic lines of force is same, those magnetic
lines repel each other.
Magnetic line of force and Magnetic field.
Magnetic line of force : Imagined line which stands for electricforce have the characteristic pass the non-magnetic substance.
Magnetic field : Modification of space so that force appear onmagnetic poles or magnets
-
8/6/2019 Basic Electrik
57/108
Magnet and Magnetic ForceMagnet and Magnetic Force
These figure show the magnetic fieldof attracting and repelling magnets.
The earth is a large magnetic,surrounded by a magnetic field.
d id i
-
8/6/2019 Basic Electrik
58/108
NN SS NN SS
Magnet and Magnetic ForceMagnet and Magnetic Force If the magnetic substance ( Iron, Nickel, Tungsten ),If the magnetic substance ( Iron, Nickel, Tungsten ),
which is not magnet, is close to magnet, the magneticwhich is not magnet, is close to magnet, the magneticsubstances become a magnet .substances become a magnet .
Phenomenon that material get magnetic force withinPhenomenon that material get magnetic force within
magnetic field.magnetic field.
Magnet Magnetic
Substance
NN SS NN SS
Magnetic
Substance
Magnetic
Substance
l i d il i d i
-
8/6/2019 Basic Electrik
59/108
Magnetic field by electricchargeMagnetic field by electricchargeCurrent
Iron pieces
wire
Battery
Electro Magnetic InductionElectro Magnetic Induction
El M i I d iEl M i I d i
-
8/6/2019 Basic Electrik
60/108
Electro Magnetic InductionElectro Magnetic InductionMagnetic field around coil
M i Fl (LM i Fl (L L )L )
-
8/6/2019 Basic Electrik
61/108
Magnetic Flux (LenzMagnetic Flux (Lenzs Law)s Law)
LenzLenzs law states when a change in thes law states when a change in the
magnetic fluxmagnetic flux
occurs, then there are induced currents thatoccurs, then there are induced currents that
opposeoppose
the change in flux.the change in flux.
S l idS l id
-
8/6/2019 Basic Electrik
62/108
SolenoidSolenoid
When a current carrying conductor is wouldWhen a current carrying conductor is would
into a coil, orinto a coil, orsolenoidsolenoid, the magnetic fields, the magnetic fields
circling conductors seem to merge or joincircling conductors seem to merge or join
together.together.
A solenoid will appear as a magnetic fieldA solenoid will appear as a magnetic field
with a North Pole at one end, and s South Polewith a North Pole at one end, and s South Pole
at the opposite end.at the opposite end.
Current in
Current out
S
N
R lR l
-
8/6/2019 Basic Electrik
63/108
RelayRelay TheThe relayrelay isis aa devicedevice usedused toto controlcontrol aa largelarge flowflow ofof
currentcurrent byby meansmeans ofofaa lowlow voltage,voltage, lowlow currentcurrent circuitcircuit..
AA relayrelay isis aa magneticmagnetic switchswitch..
WhenWhen aa relayrelayss coilcoil isis magnetized,magnetized, itsits attractiveattractive forceforce
pullspulls thethe leverlever arm,arm, calledcalled armature,armature, towardtoward thethe coilcoil.. TheThe
contactcontact pointspoints onon thethe armaturearmature willwill openopen or or closeclosedependingdepending onon theirtheir normallynormally atat restrest positionposition..
T fT f
-
8/6/2019 Basic Electrik
64/108
TransformerTransformer AAtransformertransformer is a device used to transfer energy fromis a device used to transfer energy from
one circuit to another using electromagnetic induction. Aone circuit to another using electromagnetic induction. A
transformer consists of two or more coils ofwire woundtransformer consists of two or more coils ofwire wound
around a common laminated iron core.around a common laminated iron core.
Thefirst winding, which is the input winding, is calledThe
first winding, which is the input winding, is calledthe primary. This winding receives the energy from thethe primary. This winding receives the energy from the
source. The second winding, which is output winding, issource. The second winding, which is output winding, is
called the secondary. The output load is attached to thecalled the secondary. The output load is attached to the
secondary.secondary.
Primary Secondary
T fT f
-
8/6/2019 Basic Electrik
65/108
TransformerTransformer InductionInduction
CoilCoil AA producesproduces aa risingrising andand collapsingcollapsing magneticmagneticfield
fieldthatthat cutscuts acrossacross thethe conductorsconductors inin coilcoil BB.. CoilCoil BB hashas aa
voltagevoltage inducedinduced byby thethe electricalelectrical actionaction ofof coilcoil AA.. thisthis isis
thethe principleprinciple behindbehind allall transformers,transformers, thisthis principleprinciple isis
calledcalledmutualmutual inductioninduction..
IfIf thethe acac voltagevoltage sourcesource frequencyfrequency isis equalequal toto 6060 Hz,Hz, thenthen
thethe magneticmagnetic fieldfield risesrises andand collapsescollapses 120120 timestimes aa secondsecond..
Primary
Coil ASecondaryCoil B
T fT f
-
8/6/2019 Basic Electrik
66/108
Turns Ratio PrincipleTurns Ratio Principle
TheThe ratioratio betweenbetween thethe numbernumber ofof turnsturns inin thethe primaryprimary andand
secondarysecondary isis calledcalled thethe turnturnss ratioratio.. TheThe turnturnss ratioratio isis
simplysimply thethe numbernumber ofof turnsturns inin thethe primaryprimary divideddivided byby thethe
numbernumber ofof turnsturns inin thethe secondarysecondary.. WrittenWritten asas aa formulaformula::
TurnsTurns ratioratio == NpNp // Ns=Ns=1010//11 oror 1010 toto 11
TransformerTransformer
Voltage is step down.
1,000 turns 100 turns
120 V 12 V
10 to 1 ratio
12 V
-
8/6/2019 Basic Electrik
67/108
TransformerTransformer TheThe voltagevoltage ratioratio isis thethe ratioratio betweenbetween thethe voltagesvoltages ofof thethe
primaryprimary andand secondarysecondary.. ItIt isis inin thethe samesame proportionproportion asas thetheturnturnss ratioratio::
VoltageVoltage ratioratio == EpEp // EsEs == NpNp // NsNs
TheThe currentcurrent ratioratio isis thethe ratioratio betweenbetween thethe currentscurrents inin thetheprimaryprimary andand secondarysecondary.. ItIt isis inin inverseinverse proportionproportion toto thethe
turnturnss ratioratio::
CurrentCurrent ratioratio == IsIs // IpIp == NpNp // NsNs
CombiningCombining thethe threethree ratiosratios::
EpEp // EsEs == NpNp // NsNs == IsIs // IpIp
-
8/6/2019 Basic Electrik
68/108
TransformerTransformer TransformersTransformers thatthat areare usedused toto raiseraise oror lowerlower aa voltagevoltage areare
knownknown asas stepstep upup transformerstransformers andand stepstep downdowntransformerstransformers..
StepStep upup transformerstransformers havehave moremore turnsturns inin thethe secondarysecondary
thanthan thethe primaryprimary.. TheThe voltagevoltage isis increased,increased, itit stepssteps upup..
StepStep downdown transformerstransformers havehave fewerfewer turnsturns inin thethesecondarysecondary thanthan thethe primaryprimary.. TheThe voltagevoltage isis decreased,decreased, itit
stepssteps downdown..
-
8/6/2019 Basic Electrik
69/108
Automobile Ignition CoilAutomobile Ignition Coil The ignition coil produces the high voltageThe ignition coil produces the high voltage
spark in an automobile electrical system. Itspark in an automobile electrical system. It
uses a high turns ratio to develop 30,000 voltsuses a high turns ratio to develop 30,000 volts
or more across the spark plug gap.or more across the spark plug gap.
Ignition switch
Battery 12V
Ignition coil
Distributor
Spark plug
ECM
LL LL
-
8/6/2019 Basic Electrik
70/108
Surge voltage by selfSurge voltage by self--induction actioninduction action
Practice 1)Practice 1)
EvaluationEvaluation
T
V
12V BATT
+-
LenzLenzs Laws Law
LL LL
-
8/6/2019 Basic Electrik
71/108
Practice 2)Practice 2)
EvaluationEvaluation V
T
12V BATT
+-
LenzLenzs Laws Law
LL LL
-
8/6/2019 Basic Electrik
72/108
EvaluationEvaluation
N S Conductor
LenzLenzs Laws Law
V
T
-
8/6/2019 Basic Electrik
73/108
CAPACITORCAPACITOR A capacitor is a device that temporarily stores anA capacitor is a device that temporarily stores an
electric charge. A capacitor accepts or returns thiselectric charge. A capacitor accepts or returns this
charge in order to maintain a constant voltage.charge in order to maintain a constant voltage.
As the switch is closed, electrons from theAs the switch is closed, electrons from the
negative terminal of the source flow to one platenegative terminal of the source flow to one plateof the capacitor.of the capacitor.
These electrons repel electrons from the secondThese electrons repel electrons from the second
plate, which are then drawn to the positiveplate, which are then drawn to the positive
terminal of the source.terminal of the source.
The capacitor is now charged and is opposing theThe capacitor is now charged and is opposing the
source voltage.source voltage.Schematic symbols Basic Schematic diagram for capacitor.
-
8/6/2019 Basic Electrik
74/108
Conducti
l t s
i l ctric
Conducti
l t s
i l ctric
+-
+-
+-
+-
-
8/6/2019 Basic Electrik
75/108
Calculating CapacitanceCalculating Capacitance CapacitanceCapacitance isis determineddetermined byby thethe numbernumber ofofelectronselectrons thatthat
cancan bebe storedstored inin thethe capacitorcapacitor forfor eacheach voltvolt ofof appliedappliedvoltagevoltage..
CapacitanceCapacitance isis measuredmeasured inin faradsfarads (F)(F).. AA faradfarad representsrepresents
aa chargecharge ofof oneone coulombcoulomb thatthat raisesraises thethe potentialpotential 11--voltvolt..
ThisThis equationequation isis writtenwritten.. CC == QQ // EE
WhereWhere CC isis thethe capacitancecapacitance inin farads,farads, QQ isis thethe chargecharge inin
coulombs,coulombs, areare EE isis thethe voltagevoltage inin voltsvolts..
Capacitors used in electronic work have capacitiesCapacitors used in electronic work have capacities
measured in microfarads (1/1,000,000F) and Pico faradsmeasured in microfarads (1/1,000,000F) and Pico farads
(1/1,000,000 F).(1/1,000,000 F).
Microfarad is commonly written asMicrofarad is commonly written as. Pico farad is. Pico farad is
written aswritten as . Nan farad is not a common measurement of. Nan farad is not a common measurement of
-
8/6/2019 Basic Electrik
76/108
Types ofCapacitorsTypes ofCapacitors CapacitorsCapacitors areare mademade inin hundredshundreds ofofsizessizes andand typestypes..
Can type electrolyticcapacitorsCan type electrolyticcapacitors use differentuse different
methods ofplate construction.methods ofplate construction.
TheThe ceramiccapacitorceramiccapacitor is made ofa special ceramicis made ofa special ceramic
dielectric.dielectric. Mica capacitorsMica capacitors are small capacitors. They are madeare small capacitors. They are made
by stacking tinfoil plates together with thin sheets ofby stacking tinfoil plates together with thin sheets of
mica as the dielectric.mica as the dielectric.
Fixed paper capacitors , Rectangular oil filledFixed paper capacitors , Rectangular oil filledcapacitors, Tubular electrolytic capacitors, etc.capacitors, Tubular electrolytic capacitors, etc.
-
8/6/2019 Basic Electrik
77/108
Can type capacitors
Ceramic capacitor
Mica capacitor
T i t R f thT i t R f th
-
8/6/2019 Basic Electrik
78/108
Transient Response of theTransient Response of theCapacitorCapacitor
A capacitor and a resistor are connected inA capacitor and a resistor are connected in
series across a voltage source. A circuit thatseries across a voltage source. A circuit that
contains resistance and capacitance is calledcontains resistance and capacitance is called
an RC circuit.an RC circuit.
When the switch is closed in this RC circuit,When the switch is closed in this RC circuit,
the maximum current will flow. The currentthe maximum current will flow. The current
gradually decreases until the capacitor hasgradually decreases until the capacitor hasreached its full charge. The capacitor willreached its full charge. The capacitor will
charge to the level of the applied voltage.charge to the level of the applied voltage.
-
8/6/2019 Basic Electrik
79/108
Switc C
Batt r
Switc C
Batt r
E
I
-
8/6/2019 Basic Electrik
80/108
RC Time ConstantRC Time Constant
During the charge and discharge of the seriesDuring the charge and discharge of the seriesofnetwork outlined above, a period of timeofnetwork outlined above, a period of timeelapsed. This time is indicated along the base,elapsed. This time is indicated along the base,or xor x--axis, of the graphs.axis, of the graphs.
TheThe formulaformula toto determinedetermine thethe timetime constantconstant ininRCRC circuitcircuit isis:: == RR CC
Time
ER
Cha rge S te ady
stateDischarge
ER = IR
ER
-
8/6/2019 Basic Electrik
81/108
GENERATORSGENERATORS
-
8/6/2019 Basic Electrik
82/108
MagneticInductionMagneticInduction
When conductor acrossWhen conductor across the magnetic force line,the magnetic force line,
electromotive force iselectromotive force is
occurred in conductoroccurred in conductor
When conductorWhen conductor
moves inducedmoves induced voltage is generatedvoltage is generated
in the coil by inducedin the coil by induced
electromotive force.electromotive force.
GENERATORSGENERATORS
VIron
T
S N
VIron
T
S N
-
8/6/2019 Basic Electrik
83/108
GENERATORSGENERATORS
The action ofa coil turning in a magnetic field.The action ofa coil turning in a magnetic field. In position A, the coil top moves parallel to field ofIn position A, the coil top moves parallel to field of
magnetism. No voltage is produced.magnetism. No voltage is produced. I
n position B, both sides of
the coil are cutting thefield at
In position B, both sides o
fthe coil are cutting the
field atright angles. The highest voltage is produced at this rightright angles. The highest voltage is produced at this right
angle.angle. Position C is like position A, the voltage drops to zero.Position C is like position A, the voltage drops to zero. In position D, the coil is again cutting the field at rightIn position D, the coil is again cutting the field at right
angles, where the highest voltage is induced. However, inangles, where the highest voltage is induced. However, in
position D the voltage is in the opposite direction of thatposition D the voltage is in the opposite direction of that
-
8/6/2019 Basic Electrik
84/108
-
8/6/2019 Basic Electrik
85/108
Construction ofa GeneratorConstruction ofa Generator When dc is desired in theWhen dc is desired in the
outside circuit, a set ofoutside circuit, a set of
commutator segments and acommutator segments and a
set ofbrushes are used.set ofbrushes are used.
The mechanical connectionThe mechanical connection
between the outside circuitbetween the outside circuitand the armature constantlyand the armature constantly
changes because of the brushchanges because of the brush
and commutator connections.and commutator connections.
The action of the commutatorThe action of the commutatorand brushes maintains aand brushes maintains a
constant flow in one directionconstant flow in one direction
toward the outside circuit.toward the outside circuit.
-
8/6/2019 Basic Electrik
86/108
Construction ofa GeneratorConstruction ofa Generator TheThe currentcurrent inin thethe outsideoutside circuitcircuit ofof thethe dcdc
generatorgenerator alwaysalways flowsflows inin oneone directiondirection.. TheTheoutputoutput voltagevoltage ofof thethe generatorgenerator risesrises andand fallsfalls
fromfrom zerozero toto aa maximummaximum toto zero,zero, butbut alwaysalways inin
thethe samesame directiondirection.. The output is not a smooth direct current. The
weakness of pulsating dc can be improved two ways.The number of rotating coils on the armature can beincreased and commutator sections can be supplied
for each set of coils.
-
8/6/2019 Basic Electrik
87/108
-
8/6/2019 Basic Electrik
88/108
Types ofGenerationsTypes ofGenerations
Generator output is determined by the strength ofGenerator output is determined by the strength o
fthe magnetic field and the speed of rotation. Fieldthe magnetic field and the speed of rotation. Field
strength is measured in amperestrength is measured in ampere--turns. So, anturns. So, an
increase in current in the field windings willincrease in current in the field windings will
increase the times the speed of rotation.increase the times the speed of rotation. Separately Excited Field GeneratorSeparately Excited Field Generator
ThisThis isis thethe separatelyseparately excitedexcited fieldfield generatorgenerator..
WithWith thethe speedspeed constant,constant, thethe outputoutput maymay bebe variedvariedbyby controllingcontrolling thethe excitingexciting voltagevoltage ofof thethe dcdc
sourcesource.. ThisThis isis donedone byby insertinginserting resistanceresistance inin
seriesseries withwith thethe sourcesource andand fieldfield windingswindings..
-
8/6/2019 Basic Electrik
89/108
-
8/6/2019 Basic Electrik
90/108
Types ofGenerationsTypes ofGenerations SelfExcited GeneratorSelfExcited Generator
A selfA self--exited generator uses no separate sourceexited generator uses no separate source
ofvoltage to excite the generatorfield winding.ofvoltage to excite the generatorfield winding.
The selfThe self--excited generator produces a smallexcited generator produces a small
voltage when the armature windings cut acrossvoltage when the armature windings cut acrossa weak magnetic field.a weak magnetic field.
Shunt generatorShunt generator
The shunt generator derives its name fromThe shunt generator derives its name fromthe way the field pole coils are connected inthe way the field pole coils are connected in
parallel to the armatureparallel to the armature..
-
8/6/2019 Basic Electrik
91/108
Types ofGenerationsTypes ofGenerations Series generatorSeries generator
The series generator is so named because itsThe series generator is so named because itsfield windings are wired in series with thefield windings are wired in series with the
armature and the load.armature and the load.
Because of the wide difference in outputBecause of the wide difference in outputvoltage, it is not a very practical generator tovoltage, it is not a very practical generator to
use if the load varies.use if the load varies. Compound generator
The compound generator uses both series and shuntwindings in the field. The series windings are often a fewturns of large wire. The wire size of the series windings isusually the same size as the armature conductors.
-
8/6/2019 Basic Electrik
92/108
-
8/6/2019 Basic Electrik
93/108
Alternating CurrentAlternating Current Alternating current changes its direction ofAlternating current changes its direction of
flow at times in the circuit. In dc, the sourceflow at times in the circuit. In dc, the source
voltage does not change its polarity. In ac, thevoltage does not change its polarity. In ac, the
source voltage changes its polarity betweensource voltage changes its polarity between
positive and negative.positive and negative. A cycle is a sequence or chain ofeventsA cycle is a sequence or chain ofevents
occurring in a period of time. An ac cycle canoccurring in a period of time. An ac cycle can
be described as a complete set of
positive andbe described as a complete set of
positive andnegative values for ac.negative values for ac.
Frequency, measured in cycles per second orFrequency, measured in cycles per second or
hertz (Hz), is the number ofcomplete cycleshertz (Hz), is the number ofcomplete cycles
-
8/6/2019 Basic Electrik
94/108
-
8/6/2019 Basic Electrik
95/108
-
8/6/2019 Basic Electrik
96/108
AlternatorAlternator The alternator is used in the charging systemThe alternator is used in the charging system
ofall vehicles.ofall vehicles.
The output is rectified from alternating currentThe output is rectified from alternating current
to direct current for charging the battery andto direct current for charging the battery and
other electrical devices in the vehicle. Theother electrical devices in the vehicle. The
alternator has some advantages over the dcalternator has some advantages over the dc
generator. These advantages include highergenerator. These advantages include higher
output at lower speeds.output at lower speeds.
-
8/6/2019 Basic Electrik
97/108
-
8/6/2019 Basic Electrik
98/108
AlternatorAlternator The alternator is a brush type in which a current flows fromThe alternator is a brush type in which a current flows from
the brushes through the slip ring to the field coil in the rotor.the brushes through the slip ring to the field coil in the rotor. Major componentsMajor components
Rotor (field coil): generatesmagnetic fieldRotor (field coil): generatesmagnetic field
WhenWhen thethe rotorrotor isis drivendriven byby thethe pulleypulley rotation,rotation, aa currentcurrent
flowsflows fromfrom thethe bushes,bushes, throughthrough thethe slipslip ring,ring, toto thethe fieldfield coilcoil..TheThe rotorrotor corecore tabstabs thenthen becomebecome magneticmagnetic polepole..
-
8/6/2019 Basic Electrik
99/108
i i i li i i l
-
8/6/2019 Basic Electrik
100/108
Motor Operation PrinciplesMotor Operation Principles
A Magnetic field exists between the
poles of a permanent magnet. The
arrows indicate the direction of the field.
A current carrying conductor has a
magnetic field; its direction depends
on the direction of the current.
TheThe electricmotorelectricmotor converts electrical power into rotatingconverts electrical power into rotating
mechanical power.mechanical power.
RotationalRotational forceforce comescomes fromfrom thethe interactioninteraction betweenbetween thethemagneticmagnetic fieldfield foundfound aroundaround aa currentcurrent carryingcarrying conductorconductorandand aa fixedfixed magneticmagnetic fieldfield..
AA conductorconductor carryingcarrying aa currentcurrent hashas aa magneticmagnetic fieldfieldaroundaround itit.. TheThe directiondirection ofof thethe fieldfield dependsdepends onon thethedirectiondirection ofof thethe currentcurrent..
O i i i lO i i i l
-
8/6/2019 Basic Electrik
101/108
Motor Operation PrinciplesMotor Operation Principles
The field around the conductor flows with
the permanent field above the conductor
but opposes the permanent field below
the conductor. The conductor will movetoward the weakened field.
The current has been reversed in the
conductor, causing the conductor field to
reverse. Now the field is reinforced
below the conductor and weakenedabove the conductor. The conductor will
move up.
The single conductor is replaced by a coil of
conductors wound in the slots of an armature
core. Notice how the interaction of the two fields
will produce rotation. Coil A moves up and coil B
moves down. The rotation is clockwise.
C El i FC El i F
-
8/6/2019 Basic Electrik
102/108
CounterElectromotive ForceCounterElectromotive Force AA conductorconductor cutscuts throughthrough aa magneticmagnetic field,field, voltagevoltage isis
inducedinduced inin thethe movingmoving conductorconductor.. WhenWhen thethe armaturearmature beginsbegins toto rotate,rotate, thethe motormotor alsoalso
becomesbecomes aa generatorgenerator..
The generated electrical force that opposes the appliedThe generated electrical force that opposes the applied
emf is called counter electromotive force.emf is called counter electromotive force.
Take note of the polarity of the generator output with a clockwise rotation.
The motor requires the opposite polarity for aclockwise rotation
DC MDC M
-
8/6/2019 Basic Electrik
103/108
DC MotorsDC Motors The different types ofdc motors share theThe different types ofdc motors share the
common names ofdc generators such as shunt,common names ofdc generators such as shunt,series, and compound.series, and compound.
The construction of the motors is similar to theThe construction of the motors is similar to the
generator counter parts.generator counter parts.
shunt motor series motor Compound
motor
S MS M
-
8/6/2019 Basic Electrik
104/108
Starter MotorStarter Motor The starter is a reductionThe starter is a reduction
starter with astarter with a
builtbuilt--in reduction gear. Itsin reduction gear. Its
motor hasmotor has
been downsized with evenbeen downsized with evenhigherhigher
speed capability.speed capability.
-
8/6/2019 Basic Electrik
105/108
-
8/6/2019 Basic Electrik
106/108
St t M t O tiSt t M t O ti
-
8/6/2019 Basic Electrik
107/108
Starter Motor OperationStarter Motor Operation When the starter switch is ON.When the starter switch is ON.
1. Current from the battery flows from the terminal1. Current from the battery flows from the terminal SS ofofthe magnetic switch to the pullthe magnetic switch to the pull--in coilin coil PP and holdingand holdingcoilcoil HH..
2. The plunger, attracted by the magnetic flux of the pull2. The plunger, attracted by the magnetic flux of the pull--
in coil and holding coil pushes out the pinion.in coil and holding coil pushes out the pinion.
3. When the pinion engages with the ring gear, the3. When the pinion engages with the ring gear, thecontactcontact P2P2 closes.closes.
4. The large current directly flows from battery to the4. The large current directly flows from battery to the
motor.motor. 5. Turn the pinion.5. Turn the pinion.
6. No current flows to the pull6. No current flows to the pull--in coil.in coil.
St t M t O tiSt t M t O ti
-
8/6/2019 Basic Electrik
108/108
Starter Motor OperationStarter Motor Operation