ELECTRICITY

By: IST

• Greek word – Elektron means amber
• New Latin – Electricus means amber-like
• Basic part of nature and it is one of our most widely used forms of energy
• Electrons – negative Charges
• Protons – Positive charges

• Electrical charge can be generated by friction, induction or chemical change
• Potential difference (voltage) across an ideal conductor is proportional to the current through it
• Electricity is measured in units of power called watts
• James Watt invented the steam engine

​

• Electric charge – determines electromagnetic interactions
• Electric Current – movement or flow of electrically charged particles
• measured in amperes (unit of current)
• Electric current is either
• Direct Current (DC) single-direction flow
• Alternating Current (AC) repeatedly changes direction

• Electric field – electric charge on other charges in its vicinity
• Electrical Energy – form of energy present in an electric field or magnetic field
• Electric potential – capacity of an electric field to work (measured in volts)
• Electromagnetism – fundamental interaction between magnetic field and the presence and motion of an electric charge
• Electric power – name given to electrical energy production and distribution

SOURCES OF ELECTRICITY

1. Biomass – all solid material of animal or vegetable origin.
2. Geothermal – Geo means earth and thermal means heat. Heat energy of the earth (volcanoes)
3. Hydropower – hydro comes from Greek word for water. Forces of moving water from rivers or storage reservoirs (falls, dam)
4. Ocean power – Marine currents. Two-way current: ocean tides caused by gravitational pull of the moon and sun, One-way currents: rivers of ocean water flowing within the ocean.

​

5. Solar Energy – from sun. most inexhaustible and cleanest source of energy.
6. Wind Power – wind is a form of solar energy.
7. Coal energy – coal is among the fossil fuels along with oil (petroleum) and natural gas
8. Nuclear energy – energy trapped inside atoms. Electricity is generated in a nuclear reactor by the fission of atomic nuclei
9. Natural Gas – made up mostly of methane. Methane is combination of hydrogen and carbon.

​

TYPES OF ELECTRIC CIRCUIT

1. Alternating Current (AC)
• Electric charge moves forward and backward
• Voltage or current that changes polarity or direction, over time
• Back and forth motion occurs between 50 and 60 times per second
• It is called the frequency and is designated as either 50 Hertz or 60 Hertz

2. Direct Current (DC)
• movement of electric charge is only in one direction
• voltage or current that maintains constant polarity or direction, over time.
• Source of direct current: Chemical battery (electronic power supply, mechanical generator)

KINDS OF ELECTRICITY

• Static Electricity – at rest
• Buildup of electric charge
• Net presence (or imbalance) of charge on a body
• Dynamic Electricity – in motion
• Flow of electric charge
• Movement of positive and negative charge particles

ELECTRICAL SYMBOLS

Circuit symbols – used in circuit diagrams which show how a circuit is connected together.

• Wires and connections
• Switches
• Output devices
• Power supplies

​

TYPES OF ELECTRICAL CIRCUIT

• Series Circuit
• One current path
• Parallel Circuit
• Two or more current path
• Series and Parallel Circuit
• Combination of series and parallel connection in one circuit

​

​

Series Circuit

• Current – same throughout the circuit
• Itotal = I1 = I2 = I3 ….
• Voltage – equal to the sum of individual voltage
• Vtotal = V1 + V2 + V3 …
• Resistance – equal to the sum of individual resistance
• Rtotal = R1 + R2 + R3 …

Parallel Circuit

• Current – equal to the sum of individual current
• Itotal = I1 + I2 + I3 ….
• Voltage – drop across each load is the same
• Vtotal = V1 = V2 = V3 ….
• Resistance – product over sum
• Rtotal = (R1) (R2)

R1 + R2

• Voltage
• Force of an electrical current
• Volts ( Symbol : V or E )
• Current
• Flow of electricity
• Amperes ( Symbol : I )
• Resistance
• Determines the amount of current flows through component
• Ohms ( Symbol : R )
• Power
• Rate of doing work
• Watts ( Symbol : P or W )

Power

• P = E²

R

• P = I² x R
• P = I x E

Horsepower - Kilowatt

• 1 Horsepower (Hp) = 746 watts (w)
• 1 Horsepower (Hp) = 0.746 Kw
• 1 Kilowatt (Kw) = 1.34 Hp
• 1 Kilowatt (Kw) = 1,000 watts

PARTS OF ELECTRICAL CIRCUIT

Schematic Diagram – a representation of the elements of a system using abstract, graphic symbols rather than realistic pictures.

• Load – electrical device (fixture and appliances), that consumes electrical energy
• Path – are wire use as conductor; provides passage for electric current from source and back
• Control – device that control or turns the circuit on/off (switch)
• Source – provides electrical power (battery, dry cell, generators)

OHM’s LAW in Household Electrical House Wiring

• discovered by German physicist George Ohm (1787 – 1854)
• deals with the relationship between voltage and current in an ideal conductor
• states that the current through a conductor between two points is directly proportional to the potential difference or voltage across the two point, and inversely proportional to the resistance between them.
• Volts E = I x R (Voltage)
• Current I = E / R (Amperes)
• Resistance R = E / I (Ohms)

PROCEDURE IN ELECTRICAL HOUSE WIRING

• Basic Principles of Good Wiring
1. shut off the power; remove the main fuse
2. electrical wires are color coded
3. white wires are connected to other white wires
4. study the wiring diagram
5. most home wiring is complete with either No. 14 gauge or No. 12 gauge wiring. No. 14 is the smallest wiring permitted under most codes
6. always use same size cable for continuation of extended wring any circuit

Single pole switch – most basic on all electrical switching.

Installing new light and switch

• determine current to know what size of cable will you use
• run feed cable from electrical panel to switch location
• run switch cable from the switch location to light fixture
• install electric box
• install light fixtures
• make connections to switch. Splice white or neutral wires together. Connect black wires to switch terminal. Connect ground to switch ground terminal and box if it is metal
• install switch into the box
• install cover plate
• connect feed cable in main electrical panel to proper size circuit breaker, and ground / neutral bar
• test your work

​

HOUSE WIRING

House wiring methods approved by National Fire Protection Association include open conductors, concealed knob and tube wiring, surface metal raceways, armored cable, under floor raceways, non-metallic sheathed cable, electrical metallic tubing, cast-in-place raceways, wire ways and house ways.

​

Wooden Raceways Method – made of dry and quality wood and usually consists of backing and capping

The Philippine Electrical code requires the surface wooden raceways may be used in exposed dry locations, and where the maximum potential difference between conductors does not exceed 300 volts. It shall not be use in the ff;

• for concealed wiring
• where it may be subjected to mechanical injury
• in hoist ways
• in elevator shaft
• in hazardous location
2. Wooden raceways are terminated by boxes, switches and other fittings, shall be provided with a W-cut to accommodate the mica tubing inserted over the conductors.

ELECTRONICS

• Electronics – Flow of charge through non-metal conductors
• Electronic components – any physical entity whose intention is to affect the electrons
• Electrical circuit – network that has closed loop, giving a return path for current
• Network – connection of two or more components, may not necessarily be a circuit
• Conductors – metals and other substances where electrons can move freely
• Insulators – substances where electrons cannot move freely

• Transformer – an electronic devised used in producing desired voltage
• Inductors – choke or coil in circuit that oppose changes in electric current
• Semiconductors – group that are neither good conductors nor good insulators
• Resistance – measure of the difficulty to pass an electric current through that conductor
• Conductance – electric current flows through a substance

​

​

BASIC ELECTRONIC TOOLS

1. electric drill and drill bits – 1/8 inch to ½ inch. Used to drill holes on the printed circuit board that has been etched.
2. soldering iron – used for soldering of thorough hole components.
3. disordering pump - removes liquid in solder
4. vacuum pick up tool – pick and place head for transferring die or chips
5. soldering stand – keeps iron away from flammable materials
6. helping hand tool – crucial tool in doing successful electronics work
7. wire stripper – used to strip off wire insulator from its conductor
8. long nose pliers – hold components that have short leads

​

9. side cutting pliers – cut wires into shorter length before being used; trim off excess component leads
10. small tweezers – hold small components
11. allen wrench set – used to screw and unscrew Allen type of crews
12. Philips head screwdrivers
13. flat head screwdrivers
14. hammer – used in assembling projects that involved casing
15. socket wrench – include nut drivers, hex drivers and starters in assorted sizes
16. pocket knife – for cutting PCB, wires or remove some copper from the printed circuit board

​

MAINTENANCE TIPS OF ELECTRONIC TOOL

• ensure tools are used only for their intended purposes
• keep it lubricated with light firm of oil to inhibit rust
• keep tools clean and sharp
• ensure proper uses of tools are always adhered to by following instructions

​

ELECTRONIC COMPONENTS

• basic electronic element usually packaged in a discrete form with two or more connecting leads or metallic pads
• connected thru soldering to printed circuit board

Capacitors

• Passive electronic component
• Consist of two pieces of conducting material (such as metal) separated by a non-conducting (insulating) material called dielectric
• Invented by Ewald Georg von Kleist (October 1745)
• When a (voltage) potential difference exist between the conductors, an electric field is present in dielectric. This field stores energy and produces a mechanical force between the plates. The effect is greatest between wide, flat, parallel, narrowly separated conductors.

Types of Capacitor

• Electrolytic Capacitor (Electrochemical type capacitor)
• Tantalum Capacitor
• Ceramic Capacitor
• Polystyrene Film Capacitor
• Mica Capacitor
• Metalized Capacitor
• Variable Capacitor
• Trimmer Capacitor

​

Diode

• Device which conducts electricity in only one direction
• Also known as rectifier
• Used to change alternating currents into direct currents

Types of Diode

• Light emitting diode (LED)
• Avalanche diode
• Laser diode
• Schottky diode
• Zener diode
• Photodiode
• Varicap diode or Varactor diode or Rectifier diode

​

Transistor

• Commonly used to amplify or switch electronic signals
• It is fundamental building block of electronic devices
• Used in radio, telephone, computer and other electronic system
• William Shockley – father of transistor

Resistors

• Two terminal electronic component designed to oppose and electric current by producing voltage drop between its terminal
• Simplest components in any circuit
• Restrict the flow of electrons and reduce the current or voltage flowing by converting electrical energy into heat

Types of Resistor

• Variable Resistor (Potentiometer)
• Variable Resistor (Preset)
• Carbon Composition Resistor
• Film or Cermet Resistor
• Wire – Wound Resistor
• Metal oxide film Resistor
• Vitreous enamel Resistor
• Cement Resistor
• Semiconductors Resistor

​

Resistor Color Coding

Types of Circuit Board

• Breadboard
• Temporary, no soldering required
• For testing purposes
• Easy to change connections and replace components
• Strip board
• Permanent, soldered
• Has parallel strips of copper track on one side
• Can be cut with a junior hacksaw
• Printed circuit board
• Permanent, soldered
• Have copper tracks connecting the holes where the components are placed

ELECTRONIC SCHEMATIC DIAGRAM

• Electronic Symbols
• Resistor
• Capacitors
• Diodes
• Transistor
• Audio and Radio Devices
• Meters and Oscilloscope
• Sensors (input device)
• Logic gates

​

BASIC ELECTRONIC CIRCUIT TROUBLE IN APPLIANCES

• Broken wiring inside cord set
• most common problems with vacuum cleaners
• internal breaks in the conductors of cord sets caused by flexing, pulling or other long abuse
• Bad internal connections
• broken wires, corroded or loosened terminals
• operation will be intermittent or erratic – or parts of appliances will not function
• Short circuits
• two wires touching or contacting the metal case of an appliance happens too often
• due to repeated vibrations, heating and cooling cycles
• Worn, dirty or broken switches or thermostat contacts
• will result in erratic or no action when switch is flipped or thermostat knob is turned

• Gummed up lubrication, or worn or dry bearings
• due to environmental condition (dust, dirt, humidity) or poor quality control during manufacture
• Broken or worn drive belts or gears
• rotating parts do not rotate or turn slowly
• Broken parts
• caused by normal wear and tar, improper use, accidents or shoddy manufacturing
• Insect damage
• frayed insulation, short circuits caused by bodily fluids or entire bodies, remains of food and droppings.

• Electronics deals with how electrons move to create electricity and how that electric signal is carried in electric products
• Electronics depend on certain highly specialized components, such as transistors and integrated circuits, which are part of almost every electronic product.

BLESSING NOTES

• 2 voltage connected in Parallel and reconnected in series gives less light
• Circuit breaker – device automatically breaks due to overload
• Facilitate pulling – pull box
• Electrical metallic tubing – resistant coating for protection of wires
• Junction box – termination and connection
• Breaker switch – for electric shock

• Symbols – schematic diagram
• Wiring – physical appearance
• Block diagram – linear appearance
• Load – convert electrical energy into other form of energy
• Circuit – whole path
• Source – AC or DC
• Control – on/off; switch

​

• Measure resistance, ohmmeter
• Measure current, ammeter
• Measure voltage, AC voltmeter / DC voltmeter
• Measure voltage, resistance, current – multitester or multimeter
• Electrical pliers – cutting/holding
• Soldering iron – joing (circuit board)
• Fuse puller, for pulling cartridge
• Mini drill – boring holes

​

• Screwdriver – driving
• Desoldering pump – removing solder iron
• Silicon diode – rectifier
• Crystal diode – detector, signal
• Light emitting diode (LED) – lighting
• Zener diode – regulator
• Rectifier diode – convert AC to DC
• NPN base – positive; outward
• PNP base – negative; inward

• Fusion – joining hydrogen atoms
• Tension – surface
• Fission – splitting
• Friction – rubbing
• Weatherproof socket – outdoor / wet location
• Location plan, not included in electrical plans for residential house
• Surface type – beyond wall surface
• Flush type – within the wall

​

​

• Generator – mechanical
• Battery – chemical
• Transformer – magnetism
• Heat to electric energy – thermocouple
• 1^st and 2^nd band – significant digits
• Multiplier – 3^rd band
• Tolerance – 4^th band
• Anode, positive
• Cathode, negative

​

• AM, 530 KHz – 1600 Khz
• FM, 88 Mhz – 108 Mhz
• Oscillator – produce high frequency
• Soldering flux – acid used to clean metals
• 14 AWG light fixtures and circuit
• 12 AWG convenience outlet
• 8 AWG cable for service entrance
• SI standard of 14 AWG is 2.0 mm

• Electrical metallic tubing – raising to either higher or lower level
• Series connected drycell – increase amount of voltage
• Resistor – oppose, resist, limit
• Diode – one direction, convert AC to DC
• Insulator – no electron moving
• Capacitor – storage of charge
• Sine wave – rise and fall of AC and voltage

• Open resistor – infinite (no deflection)
• Erratic sound – defective volume control
• Worn out amplifier – audio frequency signal
• Broken antenna – main signal
• Blasted tuner – radio station
• Tuning capacitor – tuned to different station
• Resistor – non polarize
• Transistor, Diode, Capacitor (polarize, + - )

• Emitter, electrode with an arrow
• Self bias, base connected to collector
• Copper – commonly used, cheapest
• Silver – best conductor
• Aluminum – better conductivity than copper
• Busbar – for connecting high voltage
• Western union – housing installation
• Photoelectricity – emmission of light

• Source – supplier of electricity (battery, dry cell, generator)
• Load – electrical devices
• Control – switch on/off
• Path – circuit, wires
• Electrical pressure – volts
• Solid conductor – electrons free to move
• Bigger wire less resistance
• Bend copper without kinking, expose copper to heat

• NPN silicon base bias voltage – 0.6 volt
• Stored – memory
• Encoder – phase distortion
• Voltage divider – operating point is almost stable
• Difference in potential – voltage drop
• DC – series
• AC – parallel
• Binary processor – single integrated circuit

• Cannot be recharged – primary battery
• Wire stripper, to cut insulation
• Solder – Tin and Lead
• Forward Biased – ON Switch
• Reversed Biased – OFF Switch
• Yellow-Violet-Black-Gold, 47 ohms, 5%
• Two plates capacitor, Dielectric
• Ferric chloride, chemical used in etching copper

• Voltage in capacitor – working voltage
• Aluminum, metal used as heat sink

Computation XD

• What is the voltage required by an automatic pressure cooker having a resistance of 30 ohms when the current flowing is 8 amperes ?

​

E = I x R

= 30 x 80

= 240 Volts

• What amount of current does a 40-watt fluorescent lamp draw from a 220 volts power source ?

​

P = I x E (given is P and E)

I = P / E

= 40 / 220

= 0.18 A

​

• Two resistances of 4 ohm and 6 ohm are in series and another 10 ohm resistance in parallel to the series combination. The resultant resistance is?

Series

Rt = 4 + 6 = 10 ohms

Parallel

Rt = 10 x 10 / 10 + 10

= 100 / 20

= 5 ohms

Note: Kung nauna niyang banggitin ang parallel, yun din ang uunahin mong formula then after that tsaka ka mag series ☺

• Two resistors of 3 ohm and 15 ohm are connected in parallel to a 30 volts circuit. The current flowing through the 3 ohm resistor is?

​

I = E / R

= 30 V / 3 R

= 10 A

• Two resistors of 6 ohm and 9 ohm are connected in a series to a 120 volt source. What is the power consumed by the 6 ohm resistor?

​

P = E² / R

= 120(120) / 6

= 14400 / 6

= 2400 watts

• In a series circuit with 4 ohm, 16 ohm, and 8 ohm resistors connected in 7V source, what is the current flowing in the 4 ohm resistor ?

I = E / R

= 7V / 4R

= 1.75 A

• If 12 volts are applied to a certain lamp whose filament has a resistance of 3 ohms, the current flow through the lamp filament will be?

I = E / R

= 12V / 3R

= 4 A

​

• Resistance of 230 V lamp is 300 ohms. What current is required?

I = E / R

= 230 / 300

= 0.7666… or 0.77 A

• Electric heater uses 20Kw-hr in 8 hrs. if voltage across the heater is 240 volts, what is the resistance

P = E² / R

R = E² / P

Note* convert Kw into watts first, remember that the unit of Power is watts

20 kw x 1000 w = 20,000 watts

= 240(240) / 20,000

= 57,600 / 20,000

= 2.88 x 8 hrs

= 23.04 ohms

• Toaster takes 10A from 120V line. The power used is?

​

P = I x E

= 10 x 120

= 1200 w

​

*if Kw ang hinahanap, divide the total watts in 1000 to get the value in kw

• How many kilowatts is the water heater if it draws a current of 10 amperes and has a resistance of 23 ohms?

P = I² x R

= 10(10) x 23

= 100 x 23

= 2300 / 1000 (to convert in Kw)

= 2.3 Kw

• How many kilowatts does a certain appliance consume for 5 hrs of use, if it has a power rating of 1.5 Hp?

​

1 Hp = 0.746 Kw

= 1.5 x 0.746

= 1.119 x 5 hrs

= 5.595 or 5.6 Kw

• Find the cost using a 100W, 220V lamp for 20 hrs at Php 3.00 per Kw-hr.

​

= 100 W x 20 hours

= 2000 W / 1000 (to convert into Kw)

= 2 Kw

= 2 Kw x Php 3.00

= Php 6.00

• What is the horsepower rating of an electric water pump if it ha a power rating of 1.75 Kw?

​

1 Kw = 1.34 Hp

= 1.75 x 1.34

= 2.345 or 2.3 Hp

​

• A 200-v lamp has a resistance of 400 ohms. The power rating in watts of lamp is ?

​

P = E² / R

= 200(200) / 400

= 40000 / 400

= 100 watts

• What is the resistance of a 100 w, 110-v incandescent lamp ?

​

R = E² / P

= 110(110) / 100

= 12100 / 100

= 121 ohms

​

• A fluorescent lamp unit connected to a 110v AC line takes 1.2A and requires 110w power. What is its power factor ?

​

P = I x E

= 1.2A x 110V

= 132 w

Power factor

= 110w / 132w

= 0.83333… or 0.833

• The resistance of a 230v incandescent lamp is 300 ohms. What current is required to operate the lamp?

​

I = E / R

= 230 / 300

= 0.7666… or 0.77 A

• A group of lamps operates a current of 12 A and a voltage of 120v. What is the total power of the lamps?

​

P = I x E

= 12 x 120

= 1440 watts

​

If kilowatts

= 1440 / 1000

= 1.44 Kw

​

• A cell supplies a load current of 0.5A for a period of 20 hours until its terminal voltage falls to an unacceptable level. How long can it be expected to supply a current of 100mA?�

1 A = 1000mA

0.5 A x 1000 mA = 500 mA

= 500 mA / 100 mA

= 5 x 20 hrs

= 100 hrs

• A battery is rated 200Ah. If it is used to supply a constant current of 8Ah. How long can the battery last until it becomes unusable?�

= 200Ah / 8Ah

= 25 hours

• The resistance of 500 meters of a certain wire is 125 ohms. What length of the same wire will have a resistance of 60 ohms ?

​

= 500 meters / 125 ohms

= 4 ohms per meter

​

= 60 ohms x 4 ohms per meter

= 240 meters

GOD BLESS YOU!

Pray ka lang ☺ naniniwala ko na papasa ka!