Terminating and Connecting of Electrical Wirings and Electronics Circuits

How to Use this Module ....................................................................................................... Introduction .......................................................................................................................... Technical Terms .................................................................................................................... Learning Outcome #1.......................................................................................................... #1..........................................................................................................1 Information Sheet #1‐1 .......................................................................................................2 Operation Sheet #1‐1 ..........................................................................................................6 Learning Outcome #2.......................................................................................................... #2..........................................................................................................8 Information Sheet #2.1 .......................................................................................................9 Activity Sheet #2.1 ............................................................................................................10 10 Learning Outcome #3........................................................................................................ #3........................................................................................................13 13 Job Sheet

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Welcome to the Module “Terminating and Connecting Electrical Wiring and Electronic Circuits” . This module contains training materials and activities for you to complete. The unit of competency “Terminate and Connect Electrical Wiring and Electronic Circuits” contains knowledge, skills and attitudes required for a Computer Hardware Servicing NC II course. You are required to go through a series of learning activities in order to complete each of the learning outcomes of the module. In each learning outcome there are Job Sheets, and Activity Sheets. Follow these activities on your own and answer the Self-Check at the end of each learning activity. If you have questions, do not hesitate to ask your teacher for assistance. Recognition of Prior Learning (RPL)

You may already have some of the knowledge and skills covered in this module because you have: o been working for some time completed training in this area. o If you can demonstrate to your teacher that you are competent in a particular skill or skills, talk to him/her about having them formally recognized so you do not have to do the same training again. If you have a qualification or Certificate of Competency from previous trainings show it to your teacher. If the skills you acquired are still current and relevant to this module, they may become part of the evidence you can present for RPL. If you are not sure about the currency of your skills, discuss it with your teacher. After completing this module ask your teacher to assess your competency. Result of your assessment will be recorded in your competency profile. All the learning activities are designed for you to complete at your own pace. Inside this module you will find the activities for you to complete followed by relevant information sheets for each learning outcome. Each learning outcome may have more than one learning activity.

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Program/Course

:

Computer Hardware Servicing NC II

Unit of Competency

:

Terminate and Connect Electrical Wiring and Circuits

Module

:

Terminating and Connecting Electrical Wiring and Electronic Circuits

Electronic

INTRODUCTION

This module contains information and suggested learning activities on Computer Hardware Servicing NC II. It includes the following competencies: plan and prepare for termination/ connections of electrical wiring/electronic circuits, terminate/connect electrical wiring/electronic circuits, and test termination/connections of electrical wiring/electronic circuits. It consists of three (3) learning outcomes. Each learning outcome contains learning activities supported by each instructional sheet. Upon completion of this module, report to your teacher to assess your achievement of knowledge and skills requirement of this module. If you pass the assessment, you will be given a certificate of completion.

SUMMARY OF LEARNING OUTCOMES:

Upon completion of the module you should be able to: LO1.

Plan and prepare for termination and connection of electrical wiring and electronic circuits.

LO2.

Terminate and connect electrical wiring and electronic circuits.

LO3.

Test Termination and connection of electrical wiring and /electronic circuit.

REFERENCES:

1. Agpaoa, Feliciano, Interior and Exterior Wiring Troubleshooting, National books Store, 1991 2. Enriquez, Michael, Simple Electronics (Basic) Fully Illustrated, Antonio M. Andes Sr. Electronics Book Series 3. www.electronics‐lab.com 4. www.wikipedia.com

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Voltage

‐ The measure of the push on each electron which makes the electron move. The term potential difference and voltage are often used interchangeably to mean the “push”, thus, you may see the term electromotive force (EMF) or just the word potential to describe the electron push in certain instances.

Current

‐

The flow of electrons in the circuit.

Resistance

‐

The opposition to current flow.

Power

‐

The rate of doing work.

Resistor

‐

A device designed intentionally to have a definite amount of

resistance

Capacitor

‐

A device that stores electrical energy.

Termination

- The point where a line, channel or circuit ends.

OHS

‐

Occupational Health and Safety


Program/ Course

:

Computer Hardware Servicing NC II

Unit of Competency

:

Terminate and Connect Electrical Wiring and Electronic Circuits

Module #3

:

Terminating and Connecting Electrical Wiring and Electronic Circuits

Learning Outcome 1: Plan and Prepare for Termination and Connection of Electrical Wiring and Electronic Circuits

Assessment Criteria:

1. 2. 3. 4.

Materials are checked according to specifications and task. Appropriate tools and equipment are selected according to task requirements. Task is planned to ensure that OHS guidelines and procedures are followed. Electrical wiring electronics circuits are appropriately prepared for connection/ termination in accordance with instructions and worksite procedure.

References:

1. Agpaoa, Feliciano, Interior and Exterior Wiring Troubleshooting, National books Store, 1991 2. Enriquez, Michael, Simple Electronics (Basic) Fully Illustrated, Antonio M. Andes Sr. Electronics Book Series 3. Cardenas, Elpidio, Fundamentals and Elements of Electricity, National Book Store, 1991 4. www.wikipedia.com


Direct Current and Alternating Current Direct Current or DC is the first type of current because it was easy to produce. This type of current always flows in one direction. One of the disadvantages of using DC is the excessive voltage drop and power loss in the power lines in a long distance transmission. Batteries are common sources of direct current.

Alternating Current or AC is the solution to the problem of DC. AC allows the flow of current in two directions. Today, it is possible to step‐up electricity, a power station, transmit it to any distant place and step it down to for consumption. A transformer is the device used for stepping‐up or stepping‐down AC voltage. Common sources of AC are found in our AC outlet (Typically, 220 volts, in the Philippines).

AC and DC Wave Form

OHM’S LAW AND POWER LAW

Ohm’s law states that, for a constant current, the current in a circuit is directly proportional to the total voltage acting in the circuit and inversely proportional to the total resistance of the circuit.


The law may be expressed by the following equation if the current I is in amperes, EMF E is in volts, and the resistance R is in ohms.

The relationship of the foregoing three variables was discovered by Georg Simon Ohm, who theorized that current is in direct proportion to resistance. The relationship is explained algebraically, using this formula:

where:

R = E/I

E=IxR

I = E/R

Resistance

Voltage

Current


E – EMF in Volts R – Resistance I – Current in Amperes

A. Practice Problems:

1.

Required… I=?

E = 25 V

R = 25 Ω

G. I

H. P

2. Required… I = 9A E=?

R = 72 Ω

E. E

F.

P

Required… I = 25 A E=?

P = 100W

C. R

D. E


3. Required… I = 4.5A E=?

P = 350 W

A. E

B. R


A Simple circuit contains the minimum things needed to have a functioning electric circuit. A simple circuit requires the following: 

AC/DC source Equipment that will operate on either an AC or DC power source Battery – A dc voltage source containing two or more cells that convert chemical energy to electrical energy. Cell‐ Single unit used to convert chemical energy into a DC electrical voltage. FUSE Once you design a simple circuit on electronics, it  





is important to include a

fuse in the primary or

secondary of a transformer. 







Fuse is a safety device used to protect an electrical circuit from the effect of excessive current. Its essential component is usually a strip of metal that will melt at a given temperature. A fuse is so designed that the strip of metal can easily be placed in the electric circuit. If the current in the circuit exceed a predetermined value, the fusible metal will melt and thus break, or open the circuit. A fuse is usually rated in Amperes, which represent the maximum continuous current it could handle without blowing. The most popular type of fuse in Electronics is 3AG type. This code describes the case size and material where “G” indicates a glass materials and “A” indicates that intended for automotive application. A 3AG fuse measures approximately 32mm x 6mm.

Wires and Cable A wire is a single slender rod or filament of drawn metal. This definition restricts the term to what would ordinarily be understood as solid wire. The word “slender” is used because the length of a wire is usually large when compared to its diameter. If a wire is covered with insulation, It is an insulated wire. Although the term “wire” properly refers to the metal, it also includes the insulation. A conductor is a wire suitable for carrying an electric current. 




A stranded conductor is a conductor composed of a group of wire or any combination of group of wires. The wires in a stranded conductor are usually twisted together and not insulated from each other. 

A cable is either a stranded conductor (single‐conductor cable) or a combination of conductors insulated from one another (multiple‐conductor cable). The term “cable” is a general one and usually applies only to the large sizes of conductor. A small cable is more often called a stranded wire or cord (such as that used for an iron or a lamp cord). Cables may be bare or insulated. Insulated cables may be sheathed (covered) with lead, or protective armor. 



Switch and its function Switch is a device used to break an electric current or transfer it to another conductor. Switches are commonly used to open or close a circuit. Closed is the ON position, while open is OFF position. Normally, switch is installed in series with the line carrying current from the power source to the load. A switch is a mechanical device used to connect and disconnect a circuit at will. Switches cover a wide range of types, from subminiature up to industrial plant switching megawatts of power on high voltage distribution lines. Switch is a manually operated device capable of making, breaking, or changing the connection in an electronics or electrical circuit. A switch connected in series with one of the connecting wires of simple circuit affords a means of controlling the current in the circuit. Switch function When the switch is closed, the electron finds an interrupted path in the o circuit. Open is the OFF position of the switch, while closed is the ON position. o When the switch is opened, the current delivered by the power supply is o normally insufficient to jump the switch gap in the form of an arc and the electron flow in the circuit is blocked. 









Load – a source drives a load. Whatever component or piece of equipment is connected to a source and draws current from a source is a load on that source. The following are examples but not limited to: o Bulb Appliances  


I.

Classifications of Electronic Component

A. Passive devices

‐

A Passive Device is one that contributes no power gain

(amplification) to a circuit or system. It has no control action and does not require any input other than a signal to perform its function. In other words, "A component with no brains!" Examples are Resistors, Capacitors and Inductors.

RESISTOR This is the most common component in electronics. It is used mainly to control current and voltage within the circuit. You can identify a simple resistor by its simple cigar shape with a wire lead coming out of each end. It uses a system of color coded bands to identify the value of the component (measured in Ohms)

Capacitors, or "caps", vary in size and shape ‐ from a small surface mount model up to a huge electric motor cap the size of paint can. Whatever the size or shape, the purpose is the same. It stores electrical energy in the form of electrostatic charge.

It is charged with a magnetic field and when that field collapses it produces current in the opposite direction. Inductors are used in Alternating Current circuits to oppose changes in the existing current.


B. Active Devices are components that are capable of controlling voltages or currents and can create a switching action in the circuit. In other words, "Devices with smarts!" Examples are Diodes, Transistors and Integrated circuits.

Diodes are basically a one‐way valve for electrical current. They let it flow in one direction (from positive to negative) and not in the other direction. Most diodes are similar in appearance to a resistor and will have a painted line on one end showing the direction or flow (white side is negative). If the negative side is on the negative end of the circuit, current will flow. If the negative is on the positive side of the circuit no current will flow.

LEDs are simply diodes that emit light of one form or another. They are used as indicator devices. Example: LED lit equals machine on. They come in several sizes and colors. Some even emit Infrared Light which cannot be seen by the human eye.

The transistor is possibly the most important invention of this decade. It performs two basic functions. 1) It acts as a switch turning current on and off. 2) It acts as an amplifier. This makes an output signal that is a magnified version of the input signal. Integrated Circuits, or ICs, are complex circuits inside one simple package. Silicon and metals are used to simulate resistors, capacitors, transistors, etc. It is a space saving miracle.




ELECTRONIC SCHEMATIC SYMBOLS

Wires and connections Component

Circuit Symbol

Function of Component To pass current very easily from one part of

Wire

a circuit to another. A 'blob' should be drawn where wires are connected (joined), but it is sometimes

Wires joined

omitted. Wires connected at 'crossroads' should be staggered slightly to form two T‐ junctions, as shown on the right. In complex diagrams it is often necessary to draw wires crossing even though they are not connected. I prefer the 'bridge' symbol

Wires not joined

shown on the right because the simple crossing on the left may be misread as a joint where you have forgotten to add a 'blob'!

Power Supplies/Source Component

Circuit Symbol

Function of Component Supplies electrical energy. The larger terminal (on the left) is positive (+).

Cell

A single cell is often called a battery, but strictly a battery is two or more cells joined together. Supplies electrical energy. A battery is more

Battery

than one cell. The larger terminal (on the left) is positive (+). Supplies electrical energy.

DC supply

DC = Direct Current, always flowing in one direction.


Supplies electrical energy. AC supply

AC = Alternating Current, continually changing direction. A safety device which will 'blow' (melt) if the

Fuse

current flowing through it exceeds a specified value. Two coils of wire linked by an iron core. Transformers are used to step up (increase) and step down (decrease) AC voltages. Energy

Transformer

is transferred between the coils by the magnetic field in the core. There is no electrical connection between the coils. A connection to earth. For many electronic circuits this is the 0V (zero volts) of the power

Earth

supply, but for mains electricity and some

(Ground)

radio circuits it really means the earth. It is also known as ground.

Output Devices/Loads: Lamps, Heater, Motor Component

Circuit Symbol

Function of Component A transducer which converts electrical

Lamp (lighting)

energy to light. This symbol is used for a lamp providing illumination, for example a car headlamp or torch bulb. A transducer which converts electrical

Lamp (indicator)

energy to light. This symbol is used for a lamp which is an indicator, for example a warning light on a car dashboard.

Heater

Motor


A transducer which converts electrical energy to heat.

A transducer which converts electrical energy to kinetic energy (motion).

A transducer which converts electrical

Bell

energy to sound.

A transducer which converts electrical

Buzzer

energy to sound.

A coil of wire which creates a magnetic field when current passes through it. It may have an iron core inside the coil. It can be used as a transducer converting electrical energy

Inductor

to mechanical energy by pulling on

(Coil, Solenoid)

something.

Switches Component Push Switch (push‐to‐ make) Push‐to‐Break Switch

On‐Off Switch (SPST)

Circuit Symbol

Function of Component A push switch allows current to flow only when the button is pressed. This is the switch used to operate a doorbell. This type of push switch is normally closed (on); it is open (off) only when the button is pressed. SPST = Single Pole, Single Throw. An on‐off switch allows current to flow only when it is in the closed (on) position. SPDT = Single Pole, Double Throw.

2‐way Switch (SPDT)

A 2‐way changeover switch directs the flow of current to one of two routes according to its position. Some SPDT switches have a central off position and are described as 'on‐off ‐on'.


DPST = Double Pole, Single Throw.

Dual On‐Off

A dual on‐off switch which is often used to switch

Switch

mains electricity because it can isolate both the live

(DPST)

and neutral connections.

Complete the table below:

A. Identify each of these symbols:

COMPONENTS 1.

2.

3.

4.

5.


SYMBOLS

B. Identify the following basic electronic components

COMPONENT

1.

2.

3.

4.


FIGURE

A simple circuit contains the minimum things needed to have a functioning electric circuit  







Source‐ a device used to supply AC or DC voltage Consuming‐ any device that consumes voltage, whatever component or piece of equipment that is connected to a source and draws current from a source is a load on that source. Controlling‐ any device having two states, on (closed) or off (open). Ideally having zero impedance when closed and infinite impedance when open. Protecting‐a component used to open the circuit when current exceeds a predetermined maximum value. Connecting‐ a material that conducts electric current very well and used to connect a complete path for current. CONTROLLING

source

CONSUMING

Connectin device



Procedure in Circuit Designing 1. Prepare all the tools and materials needed. 2. By using schematic symbol, make a simple circuit with the following : a. load b. consuming device c. protecting device d. consuming device e. connecting device 3. Make sure that the circuit has the following requirement that a simple circuit must have: a. A source of electrical potential difference or voltage. b. A conductive path which would allow for the movement of charges. c. An electrical resistance which is loosely defined as any object that uses electricity to do work. 4. Test the designed circuit by comparing it with the sample circuit produced by your teacher.


A. Fill in the blanks with what is referred to by each of the following.

1. _______________________ Interconnection of components which provides an electrical path between two or more components. 2. _______________________ A type of circuit in which the flow of current is cut off. 3. _______________________ A circuit in which the components are connected from end to end so that the current has only one path to follow through the circuit. 4. _______________________ A circuit where there is more than one path for the current to flow through. 5. _______________________ A device used to supply AC or DC voltage. 6. _______________________ Any device having two states, ON or OFF. 7. _______________________ A safety device used to protect an electrical circuit from the effect of excessive current. 8. _______________________ pathway for carrying an electrical current. 9. _______________________ Components or pieces of equipment connected to a source which draws current from a source. 10. _______________________ A DC voltage source containing two or more cells that convert chemical energy to electrical energy.


A.

Initial Steps in Using Analog Multi‐tester

1. Connect the test probe to the appropriate jack. The red test probe to the positive (+) jack and the black to the common (‐) jack.

‐COM

+ POS

(Black)

(Red)

2. Check if the pointer rests exactly at the infinite zero position in ohmmeter range.


3. Check the probes if they are in condition. (Ohmmeter calibration) a. Set the Multi‐tester to corresponding selector resistance range. b. Short the two test probes lead together.

Zero Ohm Adjustment knob

Note: The pointer should deflect towards zero ohm reading


Zero ohm

Adjust the ohm adjustment if the pointer could not rest exactly at “O” ohm reading.

B.

As indicated, the pointer rests out of the range of ohmmeter scale. Adjust the ohm adjustment counter clockwise until the pointer rests “O” ohm reading.

Resistance Measurements 1. Always do the “Initial Steps in Using Analog Multi‐tester”. 2. In testing resistors, capacitors, diodes etc. do not touch both test probe lead, because our body also has resistance that could affect the reading value of the electronic components we are testing. 3. If you do not know the value of the resistor to be measured, find the ohmmeter selector setting until you have a clear reading in the ohmmeter scale.

Ohmmeter Scale (From infinite to Zero)

Infinite Resistance open resistor – Open connection or

Ohm Adjustment

Ohmmeter Selector Range (x1, x10, x1K, x10K ohms)


4. Select the desired resistance range scale with selector switch.


Testing a 55 K ohm resistance Range: x10 Kohm

The pointer stops at 5.5 in x10K range on selector switch

Testing a 55 K ohm resistance Range: x1 K ohm

The setting (x1K in 56K Ohm resistor) is not an advisable setting in testing 55 K ohms resistance. Because, the pointer stops somewhere in 50. You cannot clearly read the resistance value, unlike in x10K ohm setting.


Terminating and Connecting of Electrical Wirings and Electronics Circuits

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