4. Radio transmitter and receiver have common parts which are joined together
to produce circuits, and they are represented by symbols. To make it easier
for the electrician to conduct primary repairs, symbols of the component
parts are used.
Radio Transmitter and receiver
16. -Electronic components are essential in the circuit.
Circuits are used in making devices or gadgets for
human convenience.
-Electronic components play a big role in many
electronic applications, in such a way that it could
lighten our work load.
17.
18. 1. Transistor -This is an active device that changes
resistance. It is used as an electronic switch.
2. Electron tubes -These include vacuum-tube diodes
amplifiers and the cathode- ray tube (CRT), used for
visual display.
3. Visual display devices - This include the light emitting
diode (LED) and the liquid- crystal display (LCD)
4. Resistors - Used to control and limit the amount of
current in a circuit.
19. 5. Capacitors - Electronic components that has
the capacity to store electric charge
6. Inductors- These are just coil of wires. Its
main function is to concentrate the magnetic
field of electric current in the coil.
21. I. Abstract
Soldering is basically the
process of joining two or
more terminal wires
together permanently.
In soldering electronic
components, it is
necessary to follow the
steps and procedures
correctly, and use high
quality tools to be able to
produce good outputs.
22. A. Before soldering activity it is necessary to consider the
following:
1. Tin the soldering iron tip. Tinning is the process of
cleaning the tip of the soldering iron.
2. Clean the surface to be soldered. Printed circuit board
(PCB) should be cleaned.
3. Clean the terminal leads of the component to be
soldered. This is done to get rid of moist and other oily
elements.
23. B. Soldering Process:
1. Place the soldering iron tip on the surface to be
soldered.
2. Apply soldering lead to the terminals of wires, and let it
melts and slowly flows on the surface evenly.
3. Remove the soldering iron.
4. Let the lead dry.
5. Check the soldered component.
6. Cut the excess wires.
25. I. Abstract
Printed circuit board
basically made of
plastic insulation with
printed wiring and
coated with conducting
materials.
Etching is the method
of making a foil pattern
on the PCB.
26. A.Materials commonly
used in making a printed
circuit board:
1. Phenolic board or copper-
clad boards
2. Masking tape/masking
materials
3. Felt-tip marking
pens/water proof pentel pen
4. Ferric chloride solution/in
powdered form
5. Prepared full scale foil
pattern layout.
6. Knife/heavy duty cutter
