COMPETENCY BASED IN LEARNING MATERIALS

KNOWING ABOUT ELECTRONICS

LO1. TO FAMILIARIZE THE COLOR CODING OF RESISTOR

Learning Activity Special Instruction1. Prepare the assorted value of

resistors.

2. Prepare and check required material.

3. Self check.

.

a) Read information no. 1 : Resistor

B.View job sheet no.1: Color coding of resistor.

INFORMATION SHEET # 1

INTRODUCTION

Resistor

An electronic component that produces a voltage across its terminals that is proportional to the electric current passing through it in accordance with Ohm's law:

V = IR

Resistors are elements of electrical networks and electronic circuits and are ubiquitous in most electronic equipment. Practical resistors can be made of various compounds and films, as well as resistance wire (wire made of a high-resistivity alloy, such as nickel/chrome).

The primary characteristics of a resistor are the resistance, the tolerance, maximum working voltage and the power rating. Other characteristics include temperature coefficient, noise, and inductance. Less well-known is critical resistance, the value below which power dissipation limits the maximum permitted current flow, and above which the limit is applied voltage. Critical resistance is determined by the design, materials and dimensions of the resistor.

Definition of terms

I. KIND OF RESISTORS

1. CARBON FILM The most popular resistor type. This resistor made by depositing a carbon film onto a small ceramic cylinder. A small spiral groove cut into the film controls the amount of carbon between the leads, hence setting the resistance.

2. CARBON COMPOSITION is type also popular. It’s made from a mixture of carbon to increase the resistance, less carbon is added. These resistors show predictable performance, low inductance, and low capacitance. Power ratings range from about 1/4 to 2 W. Resistances range from 1 Ohm to about 100 MOhm, with tolerances around +/- 5 percent.

3. METAL OXIDE FILM This type is general purpose resistor. It uses a ceramic core coated with a metal oxide film. These resistors are mechanically and electrically stable and readable during high temperature operation.

4. PRECISION METAL FILM This type is very accurate, ultra low noise resistor. It uses a ceramic substrate coated with a metal film, all encased in an epoxy shell. These resistors are used in precision devices, such as test instruments, digital and analog devices, and audio and video devices.

5. FOIL RESISTOR Foil resistors are similar in characteristics to metal film resistors. Their main advantages are better stability and lower temperature coefficient of resistance (TCR). They have excellent frequency response, low TCR, good stability, and are very accurate. They are manufactured by rolling the same wire materials as used in precision wire wound resistors to make thin strips of foil.RS

6. FILAMENT RESISTORS Filament resistors are similar to bathtub or boat resistors except that they are not packaged in a ceramic shell (boat). The individual resistive element with the leads already crimped is coated with an insulating material, generally a high temperature varnish. They are used in applications where tolerance, TCR, and stability are not important but the cost is the governing consideration. The cost of this type is slightly higher that of carbon composition and the electrical characteristics are better.

7. POWER FILM Power film resistors are similar in manufacture to metal film or carbon film resistors. They are manufactured and rated as power resistors, with the power rating being the most important characteristic. Power film resistors are available in higher maximum values than the power wire wound resistors and have a very good frequency response. They are generally used in applications requiring good frequency response and/or higher maximum values. Generally, for power applications the tolerance is wider

8. PRECISION WIRE WOUND the within precision wire wound resistor is a highly accurate resistor (0.005%) with a very low TCR. A TCR of as little as 3ppm/o C can be achieved. However these components are too expensive for general use and are normally used in highly accurate dc applications.

9. HIGH POWER WIRE WOUND these resistors are used for high power applications. Types include vitreous enamel coated, cement, and aluminum housed wire wound resistors. Resistive elements are made from a resistive wire that is coiled around a ceramic cylinder. These are the most durable of the resistors, with high heat dissipation and high temperature stability. Resistances range from 0.1 Ohm to about 150 kOhm, with power ratings from around 2 W to as high as 500 W, or more

10. PHOTORESISTORS AND THERMISTORS type also called LDR (Light Dependent Resistor). Thermistors are temperature sensitive resistors. Increasing the temperature will decreases the resistance (in most cases).        These are special types of resistors that change resistance when heat or light is applied. Photo-resistors are made from semi-conductive materials, such as cadmium sulfide. Increasing the light level This type also called Thermistor NTC (Negative Temperature Coefficient).

11. VARIABLE RESISTORS Variable resistors provide varying degrees of resistance that can be set with the turn of a knob. Special kinds of variable resistors include potentiometers, rheostats, and trimmers. Potentiometers and rheostats are essentially the same thing, but rheostats are used specially for high power AC electricity, whereas potentiometers typically are used with lower level DC electricity. Both potentiometers and rheostats are designed for frequent adjustment.

ANSWER SHEET #1

1. These resistor is provide varying degree of resistance that can be set the turn of a knob.?

A. VARIABLE RESISTORB. PRECISION WIRE WOUND

C. HIGH POWER WIRE WOUND

D. POWER FILM

2. The within precision wire wound resistor is a highly accurate resistor (0.005%) with a very low TCR?

A. HIGH POWER WIRE WOUNDB. POWER FILM

C. FILAMENT RESISTOR

D. PRECISION WIRE WOUND

3. This type of resistor that similar to metal film resistors.

A. FILAMENT RESISTOR

B. POWER FILM

C. CARBON FILM

D. PRECISION WIRE WOUND

4. This is the most popular resistor type?

A. FILAMENT RESISTORB. CARBON FILM

C. PRECISION WIRE WOUND

D. POWER FILM

5. This is similar in manufacture to metal film or carbon film resistor?

A. FILAMENT RESISTOR

B. CARBON FILM

C. POWER FILM

D. PRECISION WIRE WOUND

6. This is type also of resistor that made in carbon material?

A. PRECISION WIRE WOUND

B. POWER FILM

C. FILAMENT RESISTOR

D.CARBON COMPOSITION

7. Type of resistor also called LDR (Light Dependent Resistor?

A. PHOTORESISTOR AND THERMISTOR

B. CARBON COMPOSITION

C. POWER FILM

D. VARIABLE RESISTOR

8. This type is very accurate, ultra low noise resistor.

A. CARBON COMPOSITION

B. HIGH POWER WIRE WOUND

C. PRECISION METAL FILM

D. FOIL RESISTOR

9. This is similar characteristics of metal film resistor.

A. CARBON COMPOSITION

B. HIGH POWER WIRE WOUND

C. PRECISION METAL FILM

D. FOIL RESISTOR

10. These resistors are used for high power applications.

A. CARBON COMPOSITION

B. HIGH POWER WIRE WOUND

C. PRECISION METAL FILM

D. FOIL RESISTOR

ANSWER KEY #1

1. A

2. D

3. A

4. B

5. C

6. D

7. A

8. C

9. C

10. B

COMPETENCY BASED LEARNING MATERIALS

LO.2 TO FAMILIARIZE THE ELECTRONICS COMPONENT

Learning Activity Special Instructions1. Prepare the entire component needed.

2. Prepare and check required materials.Self check

1.Check information no.2 : electronics

INFORMATION SHEET #2

FAMILIARIZATION OF ELECTRONIC COMPONENT

Definition of Term

Electronics is that branch of science and which makes use of the controlled motion of electrons through different media and vacuum

Electron is a subatomic particle that carries a negative electric charge. It has no known components or substructure, and therefore is believed to be an elementary particle.

An electronic circuit is composed of individual electronic components, such as resistors, transistors, capacitors, inductors and diodes, connected by conductive wires or traces through which electrical current can flow.

Introduction

An electronic component is a basic electronic element usually packaged in a discrete form with two or more connecting leads or metallic pads. Components are intended to be connected together, usually by soldering to a printed circuit board, to create an electronic circuit with a particular function (for example an amplifier, radio receiver, or oscillator). Components may be packaged singly (resistor, capacitor, transistor, diode etc.) or in more or less complex groups as integrated circuits (operational amplifier, resistor array, logic gate et

Wires and connections

 Component   Circuit Symbol  Function of Component

Wire To pass current very easily from one part of a circuit to another.

Wires joined

A 'blob' should be drawn where wires are connected (joined), but it is sometimes omitted. Wires connected at 'crossroads' should be staggered slightly to form two T-junctions, as shown on the right.

Wires not joined

In complex diagrams it is often necessary to draw wires crossing even though they are not connected. I prefer the 'bridge' symbol shown on the right because the simple crossing on the left may be misread as a join where you have forgotten to add a 'blob'!

Power Supplies

 Component   Circuit Symbol  Function of Component

Cell

Supplies electrical energy.The larger terminal (on the left) is positive (+). A single cell is often called a battery, but strictly a battery is two or more cells joined together.

BatterySupplies electrical energy. A battery is more than one cell.The larger terminal (on the left) is positive (+).

DC supplySupplies electrical energy.DC = Direct Current, always flowing in one direction.

AC supplySupplies electrical energy.AC = Alternating Current, continually changing direction.

FuseA safety device which will 'blow' (melt) if the current flowing through it exceeds a specified value.

Transformer

Two coils of wire linked by an iron core. Transformers are used to step up (increase) and step down (decrease) AC voltages. Energy is transferred between the coils by the magnetic field in the core. There is no electrical connection between the coils.

Earth(Ground)

A connection to earth. For many electronic circuits this is the 0V (zero volts) of the power supply, but for mains electricity and some radio circuits it really means the earth. It is also known as ground.

Output Devices: Lamps, Heater, Motor, etc.

 Component   Circuit Symbol  Function of Component

Lamp   (lighting)

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

Lamp   (indicator)

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

Heater A transducer which converts electrical energy to heat.

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

Bell A transducer which converts electrical energy to sound.

Buzzer A transducer which converts electrical energy to sound.

Inductor(Coil, Solenoid)

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 to mechanical energy by pulling on something.

Switches

 Component   Circuit Symbol  Function of Component

Push Switch(push-to-make)

A push switch allows current to flow only when the button is pressed. This is the switch used to operate a doorbell.

Push-to-Break Switch

This type of push switch is normally closed (on), it is open (off) only when the button is pressed.

On-Off Switch(SPST)

SPST = Single Pole, Single Throw.An on-off switch allows current to flow only when it is in the closed (on) position.

2-way Switch(SPDT)

SPDT = Single Pole, Double Throw.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'.

Dual On-Off Switch(DPST)

DPST = Double Pole, Single Throw.A dual on-off switch which is often used to switch mains electricity because it can isolate both the live and neutral connections.

Reversing Switch(DPDT)

DPDT = Double Pole, Double Throw.This switch can be wired up as a reversing switch for a motor. Some DPDT switches have a central off position.

Relay

An electrically operated switch, for example a 9V battery circuit connected to the coil can switch a 230V AC mains circuit.NO = Normally Open, COM = Common, NC = Normally Closed.

Capacitors

 Component   Circuit Symbol  Function of Component

Capacitor

A capacitor stores electric charge. A capacitor is used with a resistor in a timing circuit. It can also be used as a filter, to block DC signals but pass AC signals.

Capacitor, polarised

A capacitor stores electric charge. This type must be connected the correct way round. A capacitor is used with a resistor in a timing circuit. It can also be used as a filter, to block DC signals but pass AC signals.

Variable   Capacitor A variable capacitor is used in a radio tuner.

Trimmer Capacitor

This type of variable capacitor (a trimmer) is operated with a small screwdriver or similar tool. It is designed to be set when the circuit is made and then left without further adjustment.

Diodes

 Component   Circuit Symbol  Function of Component

Diode A device which only allows current to flow in one direction.

LEDLight   Emitting   Diode

A transducer which converts electrical energy to light.

Zener DiodeA special diode which is used to maintain a fixed voltage across its terminals.

Photodiode A light-sensitive diode.

Transistors

 Component   Circuit Symbol  Function of Component

Transistor   NPN A transistor amplifies current. It can be used with other components to make an amplifier or switching circuit.

Transistor   PNP A transistor amplifies current. It can be used with other components to make an amplifier or switching circuit.

Phototransistor A light-sensitive transistor.

Audio and Radio Devices

 Component   Circuit Symbol  Function of Component

Microphone A transducer which converts sound to electrical energy.

Earphone A transducer which converts electrical energy to sound.

Loudspeaker A transducer which converts electrical energy to sound.

Piezo   Transducer A transducer which converts electrical energy to sound.

Amplifier(general symbol)

An amplifier circuit with one input. Really it is a block diagram symbol because it represents a circuit rather than just one component.

Aerial(Antenna)

A device which is designed to receive or transmit radio signals. It is also known as an antenna.

Meters and Oscilloscope

 Component   Circuit Symbol  Function of Component

Voltmeter

A voltmeter is used to measure voltage. The proper name for voltage is 'potential difference', but most people prefer to say voltage!

Ammeter An ammeter is used to measure current.

GalvanometerA galvanometer is a very sensitive meter which is used to measure tiny currents, usually 1mA or less.

Ohmmeter An ohmmeter is used to measure resistance. Most multimeters have an ohmmeter setting.

OscilloscopeAn oscilloscope is used to display the shape of electrical signals and it can be used to measure their voltage and time period.

Sensors (input devices)

 Component   Circuit Symbol  Function of Component

LDRA transducer which converts brightness (light) to resistance (an electrical property). LDR = Light Dependent Resistor

Thermistor A transducer which converts temperature (heat) to resistance (an electrical property).

Logic Gates

Logic gates process signals which represent true (1, high, +Vs, on) or false (0, low, 0V, off). For more information please see the Logic   Gates page. There are two sets of symbols: traditional and IEC (International Electro technical Commission).

Gate Type

Traditional Symbol

IEC Symbol Function of Gate

NOT

A NOT gate can only have one input. The 'o' on the output means 'not'. The output of a NOT gate is the inverse (opposite) of its input, so the output is true when the input is false. A NOT gate is also called an inverter.

ANDAn AND gate can have two or more inputs. The output of an AND gate is true when all its inputs are true.

NAND

A NAND gate can have two or more inputs. The 'o' on the output means 'not' showing that it is a Not AND gate. The output of a NAND gate is true unless all its inputs are true.

OR

An OR gate can have two or more inputs. The output of an OR gate is true when at least one of its inputs is true.

NOR

A NOR gate can have two or more inputs. The 'o' on the output means 'not' showing that it is a Not OR gate. The output of a NOR gate is true when none of its inputs are true.

EX-OR

An EX-OR gate can only have two inputs. The output of an EX-OR gate is true when its inputs are different (one true, one false).

EX-NOR

An EX-NOR gate can only have two inputs. The 'o' on the output means 'not' showing that it is a Not EX-OR gate. The output of an EX-NOR gate is true when its inputs are the same (both true or both false).

ANSWER SHEET #2

1. A transducer which converts electrical energy to heat?

A. MOTOR

B. HEATER

C. BATTERY

D. OSCILLOSCOPE2. Is used to display the shape of electrical signals and it can be used to measure their voltage and time period?

A. MOTOR

B. HEATER

C. BATTERY

D. OSCILLOSCOPE

3. Is used to measure resistance?

A. MOTOR

B. HEATER

C. BATTERY

D. OHMMETER

4. Is used to measure current?

A. OHMMETER

B. GALVANOMETER

C. AMMETER

D. VOLTMETER

5. Is used to measure voltage?

A. OHMMETER

B. GALVANOMETER

C. AMMETER

D. VOLTMETER

6. Is a very sensitive meter which is used to measure tiny currents, usually 1mA or less?

A. OHMMETER

B. GALVANOMETER

C. AMMETER

D. VOLTMETER

7. Process of signal which represent true or false?

A. LOGIC GATES

B. INTEGRATED CIRCUIT

C. MICROPHONE

D. DIODE

8. A transducer which converts sound to electrical energy?

A. LOGIC GATES

B. INTEGRATED CIRCUIT

C. MICROPHONE

D. DIODE

9. A device which only allows current to flow in one direction?

A. LOGIC GATES

B. INTEGRATED CIRCUIT

C. MICROPHONE

D. DIODE10. A transducer which converts electrical energy to light?

A. ZENER DIODE

B. LIGHT EMITTING DIODE

C. PHOTODIODE

D. DIODE

ANSWER KEY #2

1. B

2. D

3. D

4. C

5. D

6. B

7. A

8. C

9. D

10. B

COMPETENCY BASED IN LEARNING MATERIAL

LO.3 Solder/ Desolder to the board.

Learning Activity

1. Prepare the entire component needed.

2. Prepare and check required materials.

1.Check information no.3

2. View job sheet no.3

INFORMATION SHEET #3

SOLDER/DESOLDER OF THE BOARD

Introduction

There are many types of soldering pencils, guns and irons that are adequate for home use. Most home-use soldering tools are heated electrically. There are soldering tips that can be used with your propane torch. There is even a small refillable butane gas-powered soldering tool.

A good soldering technician observes the following stages of preparation for each job.

1. Cleaning all components, circuit boards, tools, and materials to be used for the soldering process.

2. Selecting the flux. 3. Determining the heat to be used and the length of time to do the job, which are based on

the thermal mass of the parts to be connected? 4. Selecting the solder. 5. Choosing the flux remover.

How to Desolder

Step 1: EquipmentDesoldering requires two main things: a soldering iron and a device to remove solder. Soldering irons are the heat source used to melt solder. Irons of the 15W to 30W range are good for most electronics/printed circuit board work. Anything higher in wattage and

you risk damaging either the component or the board. Note that you should not use so-called soldering guns. These are very high wattage and generate most of their heat by passing an electrical current through a wire. Because of this, the wire carries a stray voltage that could damage circuits and components. The choice of your solder removing device is also important. There are two main ones; vacuum pumps (solder suckers) and solder wick. They both do the same thing, so what you use will depend on your personal opinion or experiences. I suggest keeping both on hand though, as you may find that each works well in different situations. Solder suckers usually look like large syringes. There is a spring loaded plunger, and a button to release it. The plunger is pushed down. When you want to suck up the solder, you position the nozzle over the molten solder and hit the button. The plunger moves up, creating a vacuum and sucking up the solder. Solder wick, on the other hand, has no moving parts. It looks like wick used in oil lamps, except that it is made of copper. To use it, you put the wick over the joint and heat it. One thing to note about solder wick is that it is expensive, and because it is expendable, a solder sucker may be a better choice if you plan to do a lot of desoldering. I personally prefer to use a sucker to remove most of the solder, then finish up with the wick.

Remember that when desoldering, the resin in the solder and the coating on the board may releases fumes. These fumes are harmful to your eyes and lungs. Therefore, always work in a well ventilated area. Hot solder is also dangerous. Be sure not to let it splash around because it will burn you almost instantly. Eye protection is also advised.

Step 2: Surface PreparationThere isn't really too much to worry about when removing solder. Just make sure to get any grease, varnish or glue off the joint before you start heating. If you don't, you will probably foul the tip of your soldering iron pretty quickly.

Step 3: Apply HeatLay the iron tip so that it rests against both the component lead and the board. Normally, it takes one or two seconds to heat the component up enough to solder, but larger components and larger soldering pads on the board can increase the time.

Step 4: Remove SolderSolder SuckerPush down the plunger so it locks into place. Usually, you will feel or hear a click. If the tool has been used before, a small "plug" of solder may be pushed out of the nozzle. Once the solder sucker is cocked, put the nozzle into the molten solder and press the button. The plunger will pop up quickly take the solder with it. This should remove most, if not all, the solder from the joint. Don't worry if the tip softens a little, but don't melt it. You may need to repeat this step a few times in order to get all the solder.Solder WickYou will probably want to heat the wick first. Before applying any heat to the joint, lay the wick over it and put the tip of the iron on the wick. It will take a second or two to heat up, but once it is hot you will feel the wick slide. You should also see the solder flow into it. You probably won't have to repeat this step. Once a section of wick is filled with solder, it is used up and must be replaced. Since the wick comes on a spool, all you need to do is cut off the used sections and take some more off the spool.

Step 5: Clean UpYou may wish to clean the solder pad and surrounding pad to remove any resin and left over solder. There are commercial products available to take off the resin, but 000 steel wool works well of you are careful.

Damaged Solder Pads

Occasionally, you may damage a solder pad in your efforts. Usually, this just involves lifting the pad from the board, but not actually separating the traces. If this is the case, then it should be fine if you just leave it. If this is not the case and you actually break the trace, you will need to use a

small piece of wire to connect the pad to where it is supposed to go. Just follow the trace until you find a suitable location for soldering. Usually, this is the next closest solder joint. Then, jumper the wire between the two points.

OPERATIONAL SHEET

Operation Title: SOLDER/DESOLDER OF THE BOARD

Purpose: the student will learn how to execute the proper Solder/desolder of the board.

Condition/situationFor the operation: you need the materials needed are complete.

Laboratory works: Soldering iron, soldering stand, soldering lead,Soldering paste.

Procedure:

1. Use heatsinks. Heatsinks are a must for the leads of sensitive components such as ICs

and transistors. If you don't have a clip on heatsink, then a pair of pliers is a good substitute.

2. Keep the iron tip clean. A clean iron tip means better heat conduction. Use a wet sponge to clean the tip between joints.

3. Check the pads. Use a continuity tester to check to make sure you did not damage the pad or trace when you removed the solder. If you did, then follow the steps above to fix it.

4. Use the proper iron. Remember that bigger joints will take longer to heat up with a 30W iron than with a 150W iron. While 30W is good for printed circuit boards and the like, higher wattages are great when desoldering heavy connections, such as those to a chassis.

5. Use both a solder sucker and solder wick. Use a solder sucker to remove the majority of the solder, then follow up with the wick to finish things up..

EVIDENCE GUIDE

UNIT OF COMPETENCY: KNOWING ABOUT ELECTRONICS

LO1. TO FAMILIARIZE THE COLOR CODING OF RESISTOR

Learning Activity Special Instruction

1. Prepare the assorted value of resistors.

2. Prepare and check required material.

3. Self check.

.

1. Read information no.1

LO.2 to familiarize electronics component

Learning Activity Special Instructions 1. Prepare the entire component needed.

2. Prepare and check required materials.

1.Check information no.2 : electronics