COMPETENCY BASED IN LEARNING MATERIALS KNOWING ABOUT ELECTRONICS
LO1. TO FAMILIARIZE THE COLOR CODING OF RESISTOR
Learning Activity 1. Prepar pare the resistors.
assorted
value
Special Instruction a) Read information no. 1 : Resistor of
2. Prepare and check required material.
3. Self check.
.
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: 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, resistance, the tolerance, tolerance, maximum working voltage and the power rating. Other characteristics include temperature coefficient, coefficient, noise, noise, and inductance. Less well-known is critical resistance, the value below which power dissipation limits the maxim maximum um permit permitted ted curren currentt flow, flow, and above above which which the limit limit is applie applied d voltag voltage. e. Criti Critical cal resistance is determined by the design, materials and dimensions of the resistor. Definition of terms I. KIND OF RESISTORS 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.
CARBON COMPOSITION 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 indu induct ctan ance ce,, and and low low capac capacit itan ance ce.. Powe Powerr rati rating ngs s rang range e from from abou aboutt 1/4 1/4 to 2 W. Resistances range from 1 Ohm to about 100 MOhm, with tolerances around +/- 5 percent.
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.
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 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 varnis varnish. h. They They are used used in appli applicat cation ions s where where tolera tolerance nce,, TCR, TCR, and stabil stability ity 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 important characteri characteristic. stic. Power film resistors resistors are available available in higher maximum maximum values than the power wire wound resistors 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. Resist Resistive ive elements elements are made made from from a resist resistive ive wire that that is coiled coiled around around a cerami ceramic c 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). Thermi Thermisto stors rs are temper temperatu ature re sensit sensitiv ive e resist resistors ors.. Increa Increasin sing g the temper temperatu ature re will 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 semiconductive 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 rheostats are used specially specially for high power AC electricity, electricity, whereas potentiometer potentiometers s typically are used with lower level DC electricity. Both potentiometers and rheostats are designed for frequent adjustment.
ANSWER SHEET #1 These resistor is provide varying varying degree of resistance that can be set the turn of a knob.?
VARIABLE RESISTOR PRECISION WIRE WOUND HIGH POWER WIRE WOUND POWER FILM 2. The within within precision wire wire wound resistor resistor is a highly accurate resistor resistor (0.005%) with with a very low TCR?
HIGH POWER WIRE WOUND POWER FILM FILAMENT RESISTOR PRECISION WIRE WOUND 3. This type of resistor that similar similar to metal film resistors. resistors. A. FILAMENT RESISTOR B. POWER FILM C. CARBON FILM D. PRECISION WIRE WOUND 4. This is the most popular resistor type? FILAMENT RESISTOR CARBON FILM PRECISION WIRE WOUND POWER FILM
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
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 1. Prepar Prepare e the the entir entire e compo componen nentt neede needed. d.
2. Prepare and check required materials. Self check
INFORMATION SHEET #2
Special Instructions 1.Check information no.2 : electronics
FAMILIARIZATION OF ELECTRONIC COMPONENT Definition of Term Electronics is that branch of science of science and which makes use of the controlled motion of electrons of electrons through different media and vacuum Electron is a subatomic particle that carries a negative electric charge. charge. It has no known components or substructure, and therefore is believed to be an elementary particle. particle.
An
electronic circuit is composed composed of individual individual electronic electronic components components,, such as resistors resistors,, transistors, capacitors, inductors and diodes, connected by conductive wires or traces through which electrical current can flow. flow.
Introduction An electronic component is a basic electronic eleme element nt usuall usually y packag packaged ed 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 or oscillator ). ). Components may be packaged singly (resistor, (resistor, capacitor, transistor, diode etc.) or in more or less complex groups as integrated circuits (operational amplifier , resistor array, 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 connec connected ted (joine (joined), d), but it is someti sometimes mes omitted. omitted. Wires Wires connected connected at 'crossroads '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 are not not conn connec ecte ted. d. I pref prefer er the the 'bri 'bridg dge' e' symbol symbol shown on the right because 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.
Battery
Suppli Supplies es electr electrica icall energy energy.. A batter battery y is more more than one cell. The larger terminal (on the left) is positive (+).
DC supply
Supplies electrical energy. DC = Direct Direct Curren Current, t, always always flowi flowing ng in one direction.
AC supply
Supplies electrical energy. AC = Alternating Current, continually changing direction.
Fuse
A safety safety device device which which will will 'blow' 'blow' (melt) (melt) if the current flowing through it exceeds a specified value.
Transformer
Two Two coil coils s of wire wire link linked ed by an iron iron core core.. Trans Transfor former mers s are used used to step step up (incre (increase ase)) and step down (decrease) AC voltages. Energy is transferred between the coils by the magnetic fiel field d in the core. ore. There ere is no elec electr triical cal connection between the coils.
Earth (Ground)
A connec connectio tion n to earth. earth. For many many electr electroni onic c circuits this is the 0V (zero volts) of the power supply, but for mains electricity and some radio circ circui uits ts it real really ly mean means s the the eart earth. h. It is also also known as ground.
Output Devices: Lamps, Heater, Motor, etc. Component
Circuit Symbol
Function of Component
Lamp Lam p (light (li ghting ing))
A tran transd sduc ucer er whic which h conv conver erts ts elec electr tric ical al energy to light. This symbol is used for a lamp providing illumination, for example a car headlamp or torch bulb.
Lamp Lam p (indic (in dicato ator) r)
A tran transd sduc ucer er whic which h conv conver erts ts elec electr tric ical al 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 tran transd sduc ucer er whic which h conv conver erts ts elec electr tric ical al energy to heat.
Motor
A tran transd sduc ucer er whic which h conv conver erts ts elec electr tric ical al energy to kinetic energy (motion).
Bell
A tran transd sduc ucer er whic which h conv conver erts ts elec electr tric ical al energy to sound.
Buzzer
A tran transd sduc ucer er whic which h conv conver erts ts elec electr tric ical al energy to sound.
Inductor (Coil, Solenoid)
A coil of wire which creates a magnetic field when when curr curren entt passe passes s thro throug ugh h it. it. It may 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 Push Swit Switch ch (push-tomake)
A push switch allows current to flow only when when the button button is press pressed. ed. 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 = Sing Singlle Pole ole, Sin Single gle Throw hrow.. An on-off switch allows current to flow only when it is in the closed (on) position.
2-way 2-way Switc Switch h (SPDT)
SPDT SPDT = Sing Single le Pole Pole,, Doub Double le Thro Throw. w. 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 -Off Switch (DPST)
DPST DPST = Doub Double le Pole Pole,, Sing Single le Thro Throw. w. A dual on-off switch which is often used to switch switch mains mains electr electrici icity ty becaus because e it can isolate both the live and neutral connections.
Reversing Switch (DPDT)
DPDT DPDT = Doubl Double e Pole Pole,, Doub Double le Thro Throw. w. This switch can be wired up as a reversing switch for a motor. Some DPDT switches have a central off position.
Relay
An elec electr tric ical ally ly oper operat ated ed swit switch ch,, for for example a 9V battery circuit connected to the the coil coil can can swit switch ch a 230V 230V AC main mains s circuit. NO = Normal Normally ly Open, Open, COM COM = Commo Common, n, NC = Normally Closed.
Capacitors Component
Capacitor
Capacitor, polarised
Circuit Symbol
Function of Component A capaci capacitor tor stores stores electr electric ic charge charge.. A capa capaci cito torr is used used with with a resi resist stor or in a timing circuit. It can also be used as a filter, to block DC signals but pass AC signals. 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 Varia ble Capacitor Capaci tor
A variable capacitor is used in a radio tuner.
Trimmer Capacitor
This his typ type of vari ariabl able capa capaci cittor (a tri trimmer mmer)) is oper operat ate ed with a smal smalll 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.
LED Ligh Lightt Emit Emitti ting ng Diode Di ode
A transducer which converts electrical energy to light.
Zener Diode
A spec specia iall diod diode e whic which h is used used to mainta maintain in a fixed fixed voltag voltage e across across its terminals.
Photodiode
A light-sensitive diode.
Transistors Component
Circuit Symbol Function of Component
Transi Tra nsisto storr NPN
A transistor amplifies current. It can be used with other components to make an amplifier or switching circuit.
Transi Tra nsisto storr 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 Pie zo Transdu Tra nsducer cer
A transducer which converts electrical energy to sound.
Amplifier (general symbol)
An amplifier circuit with one input. Really it is a block block diagram diagram symbol because it represents 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 volt voltme mete terr is used used to meas measur ure e volt voltag age. e. The The prop proper er name name for for volt voltag age e is 'pot 'poten enti tial al diff differ eren ence ce', ', but but most most peop people le pref prefer er to say voltage!
Ammeter
An ammeter is used to measure current.
Galvanometer
A galva galvano nome mete terr is a very very sens sensit itiv ive e mete meter r 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.
Oscilloscope
An oscilloscope is used to display the shape of elec electr tric ical al sign signal als s and and it can can be used used to measure their voltage and time period.
Sensors (input devices)
Component
Circuit Symbol
Function of Component
LDR
A transducer which converts brightness (light) to resis esisttanc ance (an elec electr triical cal pro proper perty) ty). 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 Logi Lo gic c Gates Gat es 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 outp output ut of a NOT NOT gate gate is the the inve invers rse e (opposite) of its input, so the output is true when the input is false. A NOT gate is also called an inverter.
AND
An AND gate gate can have have two 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 showing that it is a Not AND gate. The output of a NAND gate gate is true unless all its inputs are true.
OR
An OR gate gate can can have have two two or more more inputs. The output of an OR gate is true when at least one of its inputs is true.
NOR
A NOR NOR gate gate can can have have two two or more more inputs. The 'o' on the output means 'not' showi showing ng 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-O EX-OR R gate gate can can only only have have two two inputs. The output of an EX-OR gate is true when its inputs are different (one true, one false).
EXNOR
An EX-N EX-NOR OR gate gate can can only only have have two 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. OSCI OSCILL LLOS OSCO COPE PE 2. 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. OSCI OSCILL LLOS OSCO COPE PE 3. Is used to measure resistance? A. MOTOR B. HEATER C. BATTERY D. OHMMETER 4. Is used to measure current? A. OHMMETER B. GALV GALVAN ANOM OMET ETER ER C. AMMETER D. VOLTM LTMETE ETER 5. Is used to measure voltage? A. OHMMETER B. GALV GALVAN ANOM OMET ETER ER C. AMMETER D. VOLTM LTMETE ETER 6. Is a very sensitive meter which is used to measure tiny currents, usually 1mA or less? A. OHMMETER B. GALV GALVAN ANOM OMET ETER ER C. AMMETER D. VOLTM LTMETE ETER 7. Process of signal which represent true or false?
A. LOG LOGIC GATES B. INTE INTEGR GRAT ATED ED CIR CIRCU CUIT IT C. MICR ICROPHON HONE D. DIODE 8. A transducer which converts sound to electrical energy? A. LOG LOGIC GATES B. INTE INTEGR GRAT ATED ED CIR CIRCU CUIT IT C. MICR ICROPHON HONE D. DIODE 9. A device which only allows current to flow in one direction? A. LOG LOGIC GATES B. INTE INTEGR GRAT ATED ED CIR CIRCU CUIT IT C. MICR ICROPHON HONE D. DIODE 10. A transducer which converts electrical energy to light? A. ZENER DIO DIOD DE B. LIGH LIGHT T EMIT EMITTI TING NG DIO DIODE DE C. PHOTO OTODIOD IODE 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.
1.Check information no.3
2. View job sheet no.3
2. Prepare and check required materials.
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 Cleaning all compone components, nts, circuit circuit boards, boards, tools, tools, and material materials s to be used for the solderi soldering ng process. 2. Sele Select ctin ing g the the flux 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. Sele Select ctin ing g the the sol solde der. r. 5. Choo Choosi sing ng the the flu flux x remo remove ver. r.
How to Desolder Step 1: Equipment Desoldering 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 socalled 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 Preparation There 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 Heat
Lay 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 Solder Solder Sucker Push 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 Wick You 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 Up You 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/situation For the operation: Laboratory works:
you need the materials needed are complete. 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 2. 3. 4.
5.
and transistors. If you don't have a clip on heatsink, then a pair of pliers is a good substitute. Keep the iron tip clean. A clean iron tip means better heat conduction. Use a wet sponge to clean the tip between joints. 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. 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. 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 1. Prepare the assorted value of resistors.
Special Instruction 1. Read information no.1
2. Prepare and check required material.
3. Self check.
.
LO.2 to familiarize electronics component
Learning Activity 1. Prepare the entire component needed.
2. Prepare and check required required materials.
Special Instructions 1.Check information no.2 : electronics
