CONSUMER ELECTRONICS SERVICING
EXPLORATORY COURSE Grades 7 and Grade 8
Table of contents
LESSON 1 – Use Hand Tools
LESSON 2 – Perform Mensuration and Calculation
LESSON 3 – Prepare and Interpret Technical Drawings
LESSON 4 – Practice Occupational Safety and Health
LESSON 5 – Maintain Tools and Equipment
LESSON 2 – Perform Mensuration and Calculation
LESSON 3 – Prepare and Interpret Technical Drawings
LESSON 4 – Practice Occupational Safety and Health
LESSON 5 – Maintain Tools and Equipment
LESSON 1 USE HAND TOOLS
Accidental - occurring unexpectedly, unintentionally, or by chance. Alternating current - an electric current that is continually varying in value and reversing its direction of flow at regular interval Anode - a positive electrode of semiconductor device Capacitance - a property that exists whenever two conductors are separated by insulating material, permitting the storage of electricity Capacitor - a component designed intentionally to have a definite amount of capacitance Circuit - an arrangement of one or more complete paths of electron flow. Conductor - a wire, cable, or other body or medium that is suitable for carrying electric current Current - the rate of transfer of electricity from one point to another Desoldering - a process of unsoldering unwanted parts or components in the circuit with the support of soldering tool Dielectric material - a material that serves as insulator because it has poor electric conductivity Direct current - an electric current that flows in one direction Discrete components- separated or individual components Electronics - a branch of science and technology that deals with the controlled flow of electrons Flammable - tending to burn quickly Hazards - risks; dangers Malfunction - not in normal functionality Ohmmeter - an instrument that measures the amount of resistance in certain component or circuits Resistance - the opposition that a component or material offers to the flow current Resistor – a component designed intentionally to have a definite amount of resistance Soldering - a process of joining two metals caused by heat Soldering technique - a right process in which the solder (lead) is being applied in a connection or in the printed circuit board Splicing – connecting two lengths of conductor Technician - a person skilled in mechanical or industrial techniques or in a particular technical field Tool kit - a small bag or box equipped with hand tools Troubleshooting - identifying and repairing faults in equipment Voltage - the electrical pressure that existed between two points and capable of producing a flow of current when a close circuit is connected between the points. Voltmeter - an instrument that measures the amount of electromotive force in a component or circuit.
Basic Hand Tools Driving of Tools
1. Screwdrivers are hand tools specifically designed to insert and tighten, or to loosen and remove screws.
A screwdriver comprises a head or tip, which engages with a screw, a mechanism to apply force by rotating the tip, and some way to position and support the screwdriver, the tip of which is shaped in to fit a particular type of screw. a. Slotted Screwdriver is used to drive or fasten negative slotted screws.
A screwdriver comprises a head or tip, which engages with a screw, a mechanism to apply force by rotating the tip, and some way to position and support the screwdriver, the tip of which is shaped in to fit a particular type of screw. a. Slotted Screwdriver is used to drive or fasten negative slotted screws.
b. Phillips Screwdriver – used to drive or fasten positive slotted screws. It is a screwdriver that could take greater torque and could provide tighter fastenings.
c. Jeweler's Screwdriver Set – is a set of small screw drivers composed of slotted and Phillips screwdrivers.
Soldering Tools
1. Soldering Iron – is a device for applying heat to melt solder in attaching two metal parts. A soldering iron is composed of a heated metal tip and an insulated handle. For electrical work, wires are usually soldered to printed circuit boards, other wires, or small terminals. A low-power iron (20-30 Watts) is suitable for this work.
2. Soldering Tool Stand – is a place where the soldering iron is placed during usage. This will keep the soldering iron away from flammable materials. The stand often comes with a sponge used in cleaning the tip of the soldering iron.
3. Desoldering tool is used in removing soldered wires and components on printed circuit boards for troubleshooting and repair purposes.
2. Soldering Tool Stand – is a place where the soldering iron is placed during usage. This will keep the soldering iron away from flammable materials. The stand often comes with a sponge used in cleaning the tip of the soldering iron.
3. Desoldering tool is used in removing soldered wires and components on printed circuit boards for troubleshooting and repair purposes.
Splicing Tools
1. Long Nose is used for holding, bending, and stretching the lead of electronic component or connecting wires.
2. Side Cutter is a wire-cutting pliers, though they are not used to grab or turn anything, but are used to cut wires.
3. Wire Stripper is a pair of opposing blades much like scissors or wire cutters. The addition of a center notch makes it easier to cut the insulation without cutting the wire.
2. Side Cutter is a wire-cutting pliers, though they are not used to grab or turn anything, but are used to cut wires.
3. Wire Stripper is a pair of opposing blades much like scissors or wire cutters. The addition of a center notch makes it easier to cut the insulation without cutting the wire.
Boring Tools
1. 12V Mini-Drill – is used to bore or drill holes in the printed circuit board (PCB) with sizes from 1/32” – 1/16”.
2. Portable Electric Drill is used for boring hole(s) in plastic or metal chassis with the used of drill bits having sizes from 1/6” to approximately 1/4”.
3. Metal Files These are hand tools having a series of sharp, parallel ridges or teeth. Most files have a narrow, pointed tang at one end to which a handle can be fitted.
· Flat File is parallel in width and tapered in thickness; they are used for flat surfaces and edges.
· Half Round File is tapered in width and thickness, coming to a point, and is narrower than a standard half round and used for filing inside of rings.
· Round File - is also called rat-tail file which is gradually tapered and used for many tasks that require a round tool, such as enlarging round holes or cutting a scalloped edge.
2. Portable Electric Drill is used for boring hole(s) in plastic or metal chassis with the used of drill bits having sizes from 1/6” to approximately 1/4”.
3. Metal Files These are hand tools having a series of sharp, parallel ridges or teeth. Most files have a narrow, pointed tang at one end to which a handle can be fitted.
· Flat File is parallel in width and tapered in thickness; they are used for flat surfaces and edges.
· Half Round File is tapered in width and thickness, coming to a point, and is narrower than a standard half round and used for filing inside of rings.
· Round File - is also called rat-tail file which is gradually tapered and used for many tasks that require a round tool, such as enlarging round holes or cutting a scalloped edge.
Cutting Tools
1. Utility Knife is a common tool used in cutting various trades and crafts for a variety of purposes.
2. Hacksaw is used for cutting metals. Some have pistol grips which keep the hacksaw firm and easy to grip. The small hand-held hacksaws consist of a metal arch with a handle that fits around a narrow, rigid blade.
2. Hacksaw is used for cutting metals. Some have pistol grips which keep the hacksaw firm and easy to grip. The small hand-held hacksaws consist of a metal arch with a handle that fits around a narrow, rigid blade.
Auxiliary Tools
1. Magnifying Glass is a convex lens which is used to produce a magnified image of an object. The lens is usually mounted on a frame with a handle. Roger Bacon is the original inventor of the magnifying glass. A magnifying glass works by creating a magnified virtual image of an object behind the lens. Some magnifying glasses are foldable with built-in light.
2. Paint Brush – made of bristles set in handle, use for cleaning dirty parts of a circuit or an object.
2. Paint Brush – made of bristles set in handle, use for cleaning dirty parts of a circuit or an object.
Electronic equipment
Aside from hand tools, equipment are also needed for more accurate and quality output. In this connection, three of the most used equipment are presented here for you to be familiar with their uses and the proper way of maintaining them.
- Volt-Ohm-Milliammeter. It is an equipment that combines three functions: as a voltmeter that measures both ac and dc voltages; an ohmmeter that measures resistance; and milliammeter that measures small amount of dc current. As safety precautions in the maintenance of this instrument, the following should be observed:
- · Always rest the function switch at 250V AC if an OFF position is not available in the instrument.
- · For current and voltage measurements, always set the function switch in the correct setting which is a little higher than the expected current or voltage present in the circuit.
- · Place the instrument in a cool dry place, away from any magnetic devices, and free from vibrations.
b. Oscilloscope. An oscilloscope (commonly abbreviated CRO, for cathode-ray oscilloscope, or scope) is a piece of electronic test equipment that allows signal voltages to be viewed, usually as a two-dimensional graph of one or more electrical potential differences (vertical axis) plotted as a function of time or of some other voltage (horizontal axis).
c. Signal generator. A signal generator is a device which produces simple wave forms. Such devices contain an electronic oscillator, a circuit that is capable of creating a repetitive waveform. These are typically used in simple electronics repair and design where they are used to stimulate a circuit under test. Oscilloscope and signal generator should be given regular checkup for at least once a week by connecting them in the power line. This will help prevent their components from having moisture that might cause trouble in their circuits.
c. Signal generator. A signal generator is a device which produces simple wave forms. Such devices contain an electronic oscillator, a circuit that is capable of creating a repetitive waveform. These are typically used in simple electronics repair and design where they are used to stimulate a circuit under test. Oscilloscope and signal generator should be given regular checkup for at least once a week by connecting them in the power line. This will help prevent their components from having moisture that might cause trouble in their circuits.
Common Faults in Using Hand Tools
Pliers:Ø Do not increase the handle length of pliers to gain more leverage. Use a larger pair of pliers or bolt cutters if necessary.
Ø Do not substitute pliers for a wrench when turning bolts and nuts. Pliers cannot grip these items properly and might cause a slip and create an accident.
Ø Never use pliers as a hammer on the handle. Such abuse is likely to result in cracks or breaks.
Ø Cut hardened wires only with pliers designed for that purpose.
Ø Always cut the wires in right angle. Never rock from side to side or bend wire back and forth against the cutting edges.
Screwdrivers: Ø Never use screwdrivers as a pry bar, chisel, and punch stirrer or scraper.
Ø Never use screwdrivers with broken or worn-out handles. Screwdrivers of these kinds should have tags to indicate that it is defective.
Ø Never use pliers on a screwdriver for extra leverage. Only use wrench or screwdrivers specifically designed for purpose.
Utility Knives/ Blades: Ø Do not use dull blades because they require more force, thus are more likely to slip. Replace the blade when it starts to “tear” instead of cut.
Ø Never leave a knife unattended with the blade exposed.
Ø Don’t bend or apply side loads to blades by using them to open cans or loosen tight cover of containers. Blades are brittle and can snap easily.
USING TOOLS BASED ON THEIR FUNCTIONS AND OPERATION
Whenever you perform a task in the workshop you must use personal protective clothing and equipment (PPE) that are appropriate for the task and which conforms with your local safety regulations and policies. Your skill in using tools and equipment will make your work less difficult and ensure that tasks are performed properly and safely
Ø Hand Tools o screwdrivers, needle-nose pliers
ØDiagnostic Tools o Analog or digital Volt-Ohm-Milliammeter, power supply
Safety check
Ø Do not use flammable cleaners or water on electrical equipment.
Ø Make sure designated walkways are kept clear of any obstructions.
Ø Always wear protective clothing and use the appropriate safety equipment.
Ø Make sure that you understand and observe all legislative and personal safety procedures when carrying out the following tasks.
Proper Use of Hand Tools
Ø Use the proper type and size of screwdriver by matching it to the screw.
Ø Phillips and Flat Head are the most common types. Ø Do not over tighten screws because the threads may become stripped.
Ø Do not substitute pliers for a wrench when turning bolts and nuts. Pliers cannot grip these items properly and might cause a slip and create an accident.
Ø Never use pliers as a hammer on the handle. Such abuse is likely to result in cracks or breaks.
Ø Cut hardened wires only with pliers designed for that purpose.
Ø Always cut the wires in right angle. Never rock from side to side or bend wire back and forth against the cutting edges.
Screwdrivers: Ø Never use screwdrivers as a pry bar, chisel, and punch stirrer or scraper.
Ø Never use screwdrivers with broken or worn-out handles. Screwdrivers of these kinds should have tags to indicate that it is defective.
Ø Never use pliers on a screwdriver for extra leverage. Only use wrench or screwdrivers specifically designed for purpose.
Utility Knives/ Blades: Ø Do not use dull blades because they require more force, thus are more likely to slip. Replace the blade when it starts to “tear” instead of cut.
Ø Never leave a knife unattended with the blade exposed.
Ø Don’t bend or apply side loads to blades by using them to open cans or loosen tight cover of containers. Blades are brittle and can snap easily.
USING TOOLS BASED ON THEIR FUNCTIONS AND OPERATION
Whenever you perform a task in the workshop you must use personal protective clothing and equipment (PPE) that are appropriate for the task and which conforms with your local safety regulations and policies. Your skill in using tools and equipment will make your work less difficult and ensure that tasks are performed properly and safely
Ø Hand Tools o screwdrivers, needle-nose pliers
ØDiagnostic Tools o Analog or digital Volt-Ohm-Milliammeter, power supply
Safety check
Ø Do not use flammable cleaners or water on electrical equipment.
Ø Make sure designated walkways are kept clear of any obstructions.
Ø Always wear protective clothing and use the appropriate safety equipment.
Ø Make sure that you understand and observe all legislative and personal safety procedures when carrying out the following tasks.
Proper Use of Hand Tools
Ø Use the proper type and size of screwdriver by matching it to the screw.
Ø Phillips and Flat Head are the most common types. Ø Do not over tighten screws because the threads may become stripped.