tranciever major parts

Transciever Major Parts
1. Resistor = to control or limit the current.
Makikita nyo sa picture, 12v na dumaan sa resistor, na limit nya ang current sa 3v
2.Capacitor = ability to store electrical or voltage.
3. Transistor = to enlarge, extend the signal.
4. Diode = to rectify and detect the signal.
Rectify = to convert AC to DC.

what is RADIO
Radio = is an art of wireless communication.
1. Standard Radio
2. Output Transformer Less
Radio (O.T.L.)
Tube-Transistor = I.C.
(integrated circuit)

---------------------------------------------------------------------------------

Electronic Symbol
antenna
Antenna Coil
I.F. (intermidiate frequency) transformer
Ang I.F. transformer ay makikita nyo sa radyo na may kulay puti, yellow at black.
kung makikita nyo ang signal ay lumabas na nakuha sa air, or radio station. Ang ginagawa ng if transformer ,tingnan sa picture. Ay pinapaganda nya ang tunog, mula sa 99% clear papunta sa 100% clear, papunta sa speaker at maririnig na natin.

Oscillator
Coil ang kulay nya ay red.

Interstage transformer
Output transformer
Resistor
Thermistor
Volume control
Capacitor
Valuable capacitor
Diode
Battery
Ground
Speaker
Wire connected
Wire not connected
Transistor

Two kinds of transistor
1. NPN
2. PNP

1. Block Diagram

2. Pictorial Diagram
3. Schematic Diagram

-----------------------------------------------------------------------------------

1/8 watt - pinakamaliit - 1 ohm
1/4 watt - 1 ohm
1/2 watt - 1 ohm
1 watt - 1 ohm
10 watts - pinakamalaki - 1 ohm

What do resistors do?
Resistors limit current. In a
typical application, a resistor is
connected in series with an
LED:
Enough current flows to make
the LED light up, but not so
much that the LED is damaged.
Later in this Chapter, you will
find out how to calculate a
suitable value for this resistor.
Resistors are used with transducers to make sensor subsystems. Transducers are electronic components which convert energy from one form
into another, where one of the
forms of energy is electrical. A light dependent resistor, or LDR, is an example of an input transducer. Changes in the brightness of the light shining
onto the surface of the LDR
result in changes in its
resistance. As will be explained
later, an input transducer is
most often connected along with a resistor to to make a
circuit called a potential divider. In this case, the output of the potential divider will be
a voltage signal which reflects
changes in illumination. Microphones and switches are
input transducers. Output transducers include loudspeakers, filament lamps
and LEDs. Can you think of
other examples of transducers
of each type? In other circuits, resistors are
used to direct current flow to
particular parts of the circuit,
or may be used to determine
the voltage gain of an
amplifier. Resistors are used with capacitors (Chapter 4) to
introduce time delays. Most electronic circuits require
resistors to make them work
properly and it is obviously
important to find out
something about the different
types of resistor available, and to be able to choose the correct resistor value, in , , or M , for a particular application. Up Go to Checkpoint .

---------------------------------------------------------------------------------
Diode
Function Diodes allow electricity to flow
in only one direction. The arrow
of the circuit symbol shows the
direction in which the current
can flow. Diodes are the
electrical version of a valve and early diodes were actually
called valves. Forward Voltage Drop Electricity uses up a little
energy pushing its way through
the diode, rather like a person
pushing through a door with a
spring. This means that there is
a small voltage across a conducting diode, it is called
the forward voltage drop and is about 0.7V for all normal
diodes which are made from
silicon. The forward voltage
drop of a diode is almost
constant whatever the current
passing through the diode so they have a very steep
characteristic (current-voltage
graph). Reverse Voltage When a reverse voltage is
applied a perfect diode does
not conduct, but all real diodes
leak a very tiny current of a few
µA or less. This can be ignored
in most circuits because it will be very much smaller than the
current flowing in the forward
direction. However, all diodes
have a maximum reverse voltage (usually 50V or more) and if this is exceeded the
diode will fail and pass a large
current in the reverse direction,
this is called breakdown . Ordinary diodes can be split
into two types: Signal diodes which pass small currents of
100mA or less and Rectifier diodes which can pass large currents. In addition there are LEDs (which have their own page) and Zener diodes (at the bottom of this page). Connecting and
soldering Diodes must be connected the
correct way round, the diagram
may be labelled a or + for anode and k or - for cathode (yes, it really is k, not c, for
cathode!). The cathode is
marked by a line painted on
the body. Diodes are labelled
with their code in small print,
you may need a magnifying glass to read this on small
signal diodes! Small signal diodes can be damaged by heat when
soldering, but the risk is small
unless you are using a germanium diode (codes beginning OA...) in which case
you should use a heat sink
clipped to the lead between
the joint and the diode body. A
standard crocodile clip can be
used as a heat sink. Rectifier diodes are quite robust and no special
precautions are needed for
soldering them. Testing diodes You can use a multimeter or a simple tester (battery, resistor and LED) to check that a diode
conducts in one direction but
not the other. A lamp may be
used to test a rectifier diode , but do NOT use a lamp to test a signal diode because the large current passed by the lamp will
destroy the diode! Signal diodes (small
current) Signal diodes are used to
process information (electrical
signals) in circuits, so they are
only required to pass small
currents of up to 100mA. General purpose signal diodes
such as the 1N4148 are made
from silicon and have a
forward voltage drop of 0.7V. Germanium diodes such as the OA90 have a lower forward
voltage drop of 0.2V and this
makes them suitable to use in
radio circuits as detectors
which extract the audio signal
from the weak radio signal. For general use, where the size
of the forward voltage drop is
less important, silicon diodes
are better because they are
less easily damaged by heat
when soldering, they have a lower resistance when
conducting, and they have very
low leakage currents when a
reverse voltage is applied. Protection diodes for relays Signal diodes are also used to
protect transistors and ICs from
the brief high voltage produced
when a relay coil is switched
off. The diagram shows how a
protection diode is connected 'backwards' across the relay
coil. Current flowing through a relay
coil creates a magnetic field
which collapses suddenly when
the current is switched off. The
sudden collapse of the
magnetic field induces a brief high voltage across the relay
coil which is very likely to
damage transistors and ICs.
The protection diode allows the
induced voltage to drive a brief
current through the coil (and diode) so the magnetic field
dies away quickly rather than
instantly. This prevents the
induced voltage becoming high
enough to cause damage to
transistors and ICs. Rectifier diodes (large
current) Rectifier diodes are used in
power supplies to convert
alternating current (AC) to
direct current (DC), a process
called rectification. They are
also used elsewhere in circuits where a large current must
pass through the diode. All rectifier diodes are made
from silicon and therefore have
a forward voltage drop of 0.7V.
The table shows maximum
current and maximum reverse
voltage for some popular rectifier diodes. The 1N4001 is
suitable for most low voltage
circuits with a current of less
than 1A.

L.E.D - light emiting diode
Function LEDs emit light when an
electric current passes through
them. Connecting and
soldering LEDs must be connected the
correct way round, the diagram
may be labelled a or + for anode and k or - for cathode (yes, it really is k, not c, for
cathode!). The cathode is the
short lead and there may be a
slight flat on the body of round
LEDs. If you can see inside the
LED the cathode is the larger electrode (but this is not an
official identification method). LEDs can be damaged by heat
when soldering, but the risk is
small unless you are very slow.
No special precautions are
needed for soldering most
LEDs. Testing an LED Never connect an LED directly
to a battery or power supply! It will be destroyed almost
instantly because too much
current will pass through and
burn it out. LEDs must have a resistor in
series to limit the current to a
safe value, for quick testing
purposes a 1k resistor is suitable for most LEDs if your
supply voltage is 12V or less. Remember to connect the LED
the correct way round!

Zener diode
Zener diodes are used to
maintain a fixed voltage. They
are designed to 'breakdown' in
a reliable and non-destructive
way so that they can be used in reverse to maintain a fixed voltage across their terminals.
The diagram shows how they
are connected, with a resistor
in series to limit the current. Zener diodes can be
distinguished from ordinary
diodes by their code and
breakdown voltage which are
printed on them. Zener diode
codes begin BZX... or BZY... Their breakdown voltage is
printed with V in place of a
decimal point, so 4V7 means
4.7V for example. Zener diodes are rated by their
breakdown voltage and
maximum power: The minimum voltage available
is 2.4V. Power ratings of 400mW and
1.3W are common.

------------------------------------------------------------------------

TYPES OF CAPACITOR
(non polarized capacitor)
1. Mylar
2. Ceramic
3. Tantalum
4. Paper
(polarized capacitor) meaning may positive at negative sya. Di pwedeng pagpalit palitin ng koneksyon
5. Electrolytic


Variable Capacitor
Eto yung pinipihit natin sa radyo, kung anong radio station ang gusto mo mapakinggan, kung love radio o campus ka makikinig, tuner sya kumbaga.

Resistor Color Coding, General Theory, Multitester

General Theory
Ang D.C. (direct current) ay magsisimulang dumaloy sa - negative, papunta sa + positive.
The negative should reach to positive.

If walang load, ang circuit, or walang ilaw, kung makikita nyo sa picture, ay magiging 0 volts (close circuit) ay mag aapoy ito. O puputok at masusunog ang wire.

Can pass. Makakadaan ang d.c. dito sa resistor.

Can pass. Makakadaan ang d.c. dito sa diode kapag ang - negative ay galing sa k cathode, papunta sa + positive na a anode.

Can't pass. Kapag ang negative ay naggaling sa a, papunta sa k.

Can't pass. Hindi makakadaan ang D.C. dito sa capacitor.

Can't pass. Hindi makakadaan ang D.C. dito

A.C. (Alternating Current)
Kapag A.C. naman ang power supply.
Parehas din ito ng signal ng radio na galing sa hangin or frequency sa hangin.

Can pass. Makakadaan ang signal dito sa capacitor.

Can pass. Makakadaan ang signal dito sa resistor

Can pass. Makakadaan ang signal dito sa diode.

Can pass. Makakadaan ang signal dito.


Why do the
electrons move?
In a circuit the
electrons are
repelled by the
negative charge
at the negative
terminal of the battery and
attracted by the
positive charge at
the positive
terminal.
Therefore the electrons drift
away from the
negative terminal
and towards the
positive terminal
of the battery. When the
electrons reach
the positive
terminal a
chemical reaction
transfers them across the battery
and back to the
negative terminal. Compare the
electrons moving
through the cct. to
ball bearings
rolling down a
slide and the battery to a lift
which raises them
back to the top of
the slide each
time they reach
the bottom. Conventional current flow As stated above the movement
of electrons and therefore the
direction of current flow is
from the negative terminal of
the battery to the positive
terminal. However before the true nature of electricity was
known scientists assumed that
current was the result of the
movement of positively
charged particles and
therefore that current flowed from the positive to the
negative terminal. This
(incorrect) convention is still
used today and is called conventional current flow. When discussing the true
nature of current we call it electron flow. In general conventional current flow is
indicated on cct. diagrams and
true electron flow is used
when we describe how an
individual component works.
 -------------------------------------------------------------------------------
Resistor Color Coding

Rules of color Coding
1. Color nearest to the point as a first band.
2. If the 3rd band is silver, gold, black or brown the resistance value will be in OHM (hundred).
3. If the 3rd band is red, orange or yellow the resistance value will be in kilo (thousand).
4. If the 3rd band is green, blue, or violet the resistance value will be in mega (million).
5. If the 3rd band is gray or white the resistance value will be in giga (billion).
eto picture sa taas ang tinginan, makikita sa multiplier sa brown hanggang silver sa may 10 ay may makikita kayong numero, yung ay katumbas ng idadagdag na zero sa 1st at 2nd band.

Unit of Resistor Symbol
Ohm - Hundred
K - kilo - thousand
M - Mega - million
G - Giga - billion

Example.
1st, 2nd, multiplier,
1. Orange, orange, brown = 330 ohm (hundred pa lang)
2. Brown, black, orange = 10,000 = 10k (dahil thousand na)
3. Brown, green, yellow = 150,000 = 150k (dahil thousand na)
4. Yellow, violet, red = 4,700 = 4.7k (thousand)
5. Red, black, black = 20 ohm (hundred pa lang)
6. Red, black, gold = 20 x 0.1 = 2 ohm
7. Red, brown, silver = 21 x 0.01 = 0.21 ohm (hundred)
8. Red, brown, white = 21,000,000,000 = 21G (billion na kasi)
9. Red, brown, violet = 210,000,000 = 210M (million na kasi)

Tolerance - a percentage by w/c actual value of resitor, capacitor or other electrical unit may be differ from nominal value either plus + or - minus.
Madalas nating makikita ito sa resistor. Ang 4rth band nya ay tolerance. Malalaman nating good ang resistor kung hindi bababa or tataas sa tolerance percent sa actual reading.

Example.
Resistor color code
orange, orange, brown, gold
= 330 ohm -+5% ang tolerance
330
x 5%
________
= 16.50
So plus or minus 16.50 sa 330.
330 + 16.5 = 346.5
330 - 16.5 = 313.5
So kung ang reading nyo sa tester ay ay nasa pagitan ng 346.5 at 313.5 ay good ang resistor nyo. Kung lumampas or bumaba, ay deffective ang resistor.

-----------------------------------------------------------------------------

 Multimeter
Ang pinakataas ng scale na makikita sa multimeter ay para sa pagsukat ng resistance = ohm. Ang zero ay nasa kanan, at ang infinity ay nasa kaliwa. So ang pagbasa ng reading ay pakaliwa.
           2 lang ang dapat tandaan sa pagbasa ng reading. Ang una ay ang pagpili ng range (kung X1 or X10), tapos ilagay ang needle sa zero. Magagawa ito sa pagdikit ng test prob, ay i adjust ang knob (zero corrector) at itapat sa zero.
           Ang pinakamababang range ay X1. Ang pinakamataas ay X10k.
Ang X1 range ay ginagamit kung magsusukat ka ng resistance na mas mababa or hindi lalampas sa 500 ohms.
          X10 naman kung mas mababa sa 1000 ohms
          X1k kung mas mataas 1000 ohms.

V.O.M. - Voltmeter, Ohmmenter, Milliammeter= the ohmeter use for measuring resistance. The topmost scale of multi meter is for ohmmeter reading, so the attention would be focused only the scale for reading resistance, zero is located on the right side of the meter infinity is on the left side the two should be taken before making any resistance measurement the first step is to select a proper range or multiplier in the function selector.
The second step is to adjust the needle or the pointer to zero reading. This done by shorting together test probs and turning slowly the ohmeter adjust knob until the needle is pointing to zero reading. Zero adjustment should be done on any multiplier range.
Accuracy of measurement therefour multiplier range in this multi-tester if SANWA type model range are X1, X10, X1k, X10k so the lowest range is X1 this range is used for measuring low resistance not exceeding 500 ohm.

For resistance measurement or less than 1000 ohm X10 range is more accurance.

External Part of Multi-Tester.
1. Indicator cover
2. Meter scale
3. Meter pointer
4. Zero corrector
5. Range selector
6. Zero ohms adjust
7. Test prob
8. + socket
9. - socket
10. Output jack

Kinds of switch, Radio Spare Part, Circuit or Wiring Connection

Type of Switch

1. Single pole, Single throw (spst) -

A simple on-

off switch.

This type can

be used to

switch the

power supply to a circuit. When used

with mains

electricity this

type of switch

must be in the

live wire, but it is better to use

a DPST switch

to isolate both

live and

neutral.

2. Single pole, double throw (spdt)-

ON-ON

Single Pole,

Double Throw

= SPDT This switch can

be on in both

positions,

switching on a

separate device

in each case. It is often called

a changeover switch. For example, a

SPDT switch

can be used to

switch on a red

lamp in one

position and a green lamp in

the other

position. A SPDT toggle

switch may be

used as a

simple on-off

switch by

connecting to COM and one

of the A or B

terminals

shown in the

diagram. A and

B are interchangeable

so switches are

usually not

labelled. ON-OFF-ON

SPDT Centre

Off A special

version of the

standard SPDT

switch. It has a

third switching

position in the centre which is

off. Momentary

(ON)-OFF-(ON)

versions are

also available

where the switch returns

to the central

off position

when released.

3. Double pole, single throw (dpst) -

Dual ON-OFF

Double Pole,

Single Throw =

DPST A pair of on-

off switches

which operate

together

(shown by the

dotted line in the circuit

symbol). A DPST switch

is often used

to switch mains

electricity

because it can

isolate both the live and

neutral

connections.

4. Double pole, Double throw (dpdt) -

Dual ON-ON

Double Pole,

Double Throw

= DPDT A pair of on-

on switches

which operate

together

(shown by the

dotted line in the circuit

symbol). A DPDT switch

can be wired

up as a reversing

switch for a motor as

shown in the

diagram. ON-OFF-ON

DPDT Centre

Off A special

version of the

standard SPDT

switch. It has a

third switching

position in the centre which is

off. This can

be very useful

for motor

control

because you have forward,

off and reverse

positions.

Momentary

(ON)-OFF-(ON)

versions are also available

where the

switch returns

to the central

off position

when released.

Ampere = Horsepower

10A - 1 hp

15A - 1.5 hp

20A - 2 hp

30A - 3 hp

10A - 746 watt

15A - 1119 watt

20A - 1492 watt

30A - 2238 watt

60A - 4476 watt

--------------------------------------------------------------------------

 

 Function of the Radio Spare Part
1. Antenna - received of frequency modulation
Nakakatanggap sya ng F.M. (frequency modulation) band sa megaherts MHZ. Yung mga kanta sa love radio na station.
2. Antenna Coil - received amplitude modulation - A.M. band.
Radyo naman ito, na mapapakinggan natin ang balita sa KHZ kiloherts.
3. Oscillator Coil - to make the signal 100% clear.
4. I.F. Transformer - to make the signal 99% clear.
5. Interstage Transformer - to make a signal 99% sound clear (booster amplifier)
6. Resistor - ability to control, limit the flow of current.
7. Capacitor - ability to store electrical charge or voltage.
Nagstore daw or naiipon ang kuryente sa kanya, para mapaandar ang isang bagay na kailangan ng mataas na kuryente.
Meron namang capacitor na ang trabaho ay ang mag filter ng kuryente para maging malinis ang daloy ng kuryente mula sa rectifier diode. Para maging smooth ang ripple o pulsating na DC.
8. Variable Capacitor - station selector switch.
Eto yung pinipìhit natin kung anong station ng radyo ang gusto mong pakinggan. Kung love radio or campus radio ka makikinig.
9. Speaker - convert electrical energy ito sound.
Ang signal ng kuryente ay ginagawa nyang tunog. Pwede din ito pagbaliktarin, at gawing Microphone, na ang tunog ay gagawing electrical energy.
10. Microphone - convert sound to electrical energy.
11. Diode - to rectify or detect the signal.
Diodes allow electricity to flow in
only one direction. The arrow of
the circuit symbol shows the
direction in which the current can
flow. Diodes are the electrical
version of a valve and early diodes were actually called valves.
Ito ay para mapadaan ang kuryente sa isang direction lamang. At may tanda o arrow sya para malaman kung ano ang direction lamang. Kung ang + posive halimbawa ay pakanan ang daan, kanan lamang ang daan nya, hindi sya makakadaan pakaliwa, dahil pipigilan sya ng diode. Isang direction laman.
May rectifier diode naman na ang trabaho ay gawing D.C. ang A.C.
12. Transistor - to enlarge and extend the signal (amplify)
Para lumakas ang mahinang signal. Kaya may tinatawag na amplifier na ang mahinang tunog ay maging malakas pero maganda pa din ang tunog.

---------------------------------------------------------------------------
 Circuit or Wiring Connection
Electrical Prayer

From line one to switch, switch to lamp, lamp to another line.

Series Connection

Parallel Connection

3 way at 4 way switch, gamit ito para makontrol ang ilaw sa ibaw lugar.

3 way connection

4 way switch connection

Credit:
http://www.electrical-online.com/basic-4-way-switch-wiring/
http://www.ezdiyelectricity.com/?page_id=381

Common Deffect, How to know Good Resistor and Capacitor, Power Supply Project

Common Deffect
1. Open

Ito ay koneksyon na putol, kapag ginamitan ang tester ay hindi gagalaw ang pointer, nasa infinity lang.
2. Shorted

Nagdikit na ang wiring, kapag ginamitan ng tester ay gagalaw ang pointer papunta sa zero, wala ka nang mababasang resistance kundi zero.
Sa resistor ay bihirang mangyari ito. Open at Leaky lang ang madalas.
3. Change Value (Leak)

Leak= tagas.
Leaky, nagbago ang kanyang resistance, bumaba or tumaas ang value nya.

Good Resistor= the exact resistance given by an ohmmeter is with in the maximum and minimum value of the resistor.
Bad Resistor= the exact resistance given by an ohmeter is not with in the maximun and minimum value of the resistor.
Good Capacitor= the meter pointer will slightly deflect to the right side and going back to left side, to the infinity side.

Ang pagtest ng capacitor ay kelangang magdeflect sya sa kanan at babalik pakaliwa sa infinity. Pagpalitpalitin ang test prob sa terminal kung uulitin ang pagtest.

---------------------------------------------------------------------------------

 Power Supply Project
ang diode ay ganito, 1 ang direction.

Ganito ang power supply fro 220 vac to 12 vdc.
Half wave Rectifier

Full wave rectifier

Bridge Type Rectifier
Isang uri ng diode na 4 na diode na pinag isa, use para mag rectify

Step Down Power Supply

ito ay pwede kang magpalit palit ng voltage, from 3 v - 12 v.
Tandaan:
May capacitor ito at resistor para mapalinis nya ang pulsating DC.
Kapag Open na ang resistor ay 12 vdc pa din ang output voltage nya kahit inilipat sa 3 v.
Power Supply Spareparts
1 transformer 750ma
1 selector switch 5 position
4 diode IN4001 - 1 ampere
1 resistor 1k 1/4 watt
1 capacitor 1000 uf /16v

Credit:
http://www.play-hookey.com/ac_theory/ps_rectifiers.html
http://www.team-bhp.com/forum/modifications-accessories/50723-bennys-first-diy-leds-ikon-13.html http://www.tutorvista.com/topic/define-rectify
http://www.opamp-electronics.com/tutorials/rectifier_circuits_3_03_04.htm http://www.electro-tech-online.com/general-electronics-chat/110117-need-small-rectifier-design-12v-c-power-supply.html http://www.electro-tech-online.com/general-electronics-chat/110117-need-small-rectifier-design-12v-c-power-supply.html http://www.reuk.co.uk/Make-A-Bridge-Rectifier-From-Diodes.htm http://www.piclist.com/images/www/hobby_elec/e_diode.htm http://en.m.wikipedia.org/wiki/Diode_bridge?wasRedirected=true
http://www.industrial-electronics.com/Industrial_Power_Supplies_Inverters_and_Converter/5_Four-Diode_Full-Wave_Bridge_Rectifier.html

Conventional vs Electron theory

Conventional versus
electron flow "The nice thing about
standards is that there are so
many of them to choose from." Andrew S. Tanenbaum,
computer science professor When Benjamin Franklin made
his conjecture regarding the
direction of charge flow (from
the smooth wax to the rough
wool), he set a precedent for
electrical notation that exists to this day, despite the fact
that we know electrons are
the constituent units of charge,
and that they are displaced
from the wool to the wax --
not from the wax to the wool -- when those two substances
are rubbed together. This is
why electrons are said to have
a negative charge: because
Franklin assumed electric
charge moved in the opposite direction that it actually does,
and so objects he called
"negative" (representing a
deficiency of charge) actually
have a surplus of electrons. By the time the true direction
of electron flow was
discovered, the nomenclature
of "positive" and "negative"
had already been so well
established in the scientific community that no effort was
made to change it, although
calling electrons "positive"
would make more sense in
referring to "excess" charge.
You see, the terms "positive" and "negative" are human
inventions, and as such have
no absolute meaning beyond
our own conventions of
language and scientific
description. Franklin could have just as easily referred to
a surplus of charge as "black"
and a deficiency as "white," in
which case scientists would
speak of electrons having a
"white" charge (assuming the same incorrect conjecture of
charge position between wax
and wool). However, because we tend to
associate the word "positive"
with "surplus" and "negative"
with "deficiency," the standard
label for electron charge does
seem backward. Because of this, many engineers decided
to retain the old concept of
electricity with "positive"
referring to a surplus of charge,
and label charge flow (current)
accordingly. This became known as conventional flow
notation: Others chose to designate
charge flow according to the
actual motion of electrons in a
circuit. This form of symbology
became known as electron
flow notation: In conventional flow notation,
we show the motion of charge
according to the (technically
incorrect) labels of + and -. This
way the labels make sense,
but the direction of charge flow is incorrect. In electron
flow notation, we follow the
actual motion of electrons in
the circuit, but the + and -
labels seem backward. Does it
matter, really, how we designate charge flow in a
circuit? Not really, so long as
we're consistent in the use of
our symbols. You may follow
an imagined direction of
current (conventional flow) or the actual (electron flow) with
equal success insofar as circuit
analysis is concerned. Concepts
of voltage, current, resistance,
continuity, and even
mathematical treatments such as Ohm's Law (chapter 2) and
Kirchhoff's Laws (chapter 6)
remain just as valid with
either style of notation. You will find conventional
flow notation followed by
most electrical engineers, and
illustrated in most engineering
textbooks. Electron flow is
most often seen in introductory textbooks (this
one included) and in the
writings of professional
scientists, especially solid-
state physicists who are
concerned with the actual motion of electrons in
substances. These preferences
are cultural, in the sense that
certain groups of people have
found it advantageous to
envision electric current motion in certain ways. Being
that most analyses of electric
circuits do not depend on a
technically accurate depiction
of charge flow, the choice
between conventional flow notation and electron flow
notation is arbitrary . . . almost. Many electrical devices
tolerate real currents of either
direction with no difference in
operation. Incandescent lamps
(the type utilizing a thin metal
filament that glows white-hot with sufficient current), for
example, produce light with
equal efficiency regardless of
current direction. They even
function well on alternating
current (AC), where the direction changes rapidly over
time. Conductors and switches
operate irrespective of current
direction, as well. The technical
term for this irrelevance of
charge flow is nonpolarization. We could say then, that
incandescent lamps, switches,
and wires are nonpolarized
components. Conversely, any
device that functions
differently on currents of different direction would be
called a polarized device. There are many such polarized
devices used in electric circuits.
Most of them are made of so-
called semiconductor
substances, and as such aren't
examined in detail until the third volume of this book
series. Like switches, lamps,
and batteries, each of these
devices is represented in a
schematic diagram by a unique
symbol. As one might guess, polarized device symbols
typically contain an arrow
within them, somewhere, to
designate a preferred or
exclusive direction of current.
This is where the competing notations of conventional and
electron flow really matter.
Because engineers from long
ago have settled on
conventional flow as their
"culture's" standard notation, and because engineers are the
same people who invent
electrical devices and the
symbols representing them,
the arrows used in these
devices' symbols all point in the direction of conventional
flow, not electron flow. That is
to say, all of these devices'
symbols have arrow marks
that point against the actual
flow of electrons through them. Perhaps the best example of a
polarized device is the diode. A
diode is a one-way "valve" for
electric current, analogous to a
check valve for those familiar
with plumbing and hydraulic systems. Ideally, a diode
provides unimpeded flow for
current in one direction (little
or no resistance), but prevents
flow in the other direction
(infinite resistance). Its schematic symbol looks like
this: Placed within a battery/lamp
circuit, its operation is as such: When the diode is facing in the
proper direction to permit
current, the lamp glows.
Otherwise, the diode blocks all
electron flow just like a break
in the circuit, and the lamp will not glow. If we label the circuit current
using conventional flow
notation, the arrow symbol of
the diode makes perfect sense:
the triangular arrowhead
points in the direction of charge flow, from positive to
negative: On the other hand, if we use
electron flow notation to show
the true direction of electron
travel around the circuit, the
diode's arrow symbology
seems backward: For this reason alone, many
people choose to make
conventional flow their
notation of choice when
drawing the direction of
charge motion in a circuit. If for no other reason, the
symbols associated with
semiconductor components
like diodes make more sense
this way. However, others
choose to show the true direction of electron travel so
as to avoid having to tell
themselves, "just remember
the electrons are actually
moving the other way"
whenever the true direction of electron motion becomes an
issue. In this series of textbooks, I
have committed to using
electron flow notation.
Ironically, this was not my first
choice. I found it much easier
when I was first learning electronics to use conventional
flow notation, primarily
because of the directions of
semiconductor device symbol
arrows. Later, when I began
my first formal training in electronics, my instructor
insisted on using electron flow
notation in his lectures. In fact,
he asked that we take our
textbooks (which were
illustrated using conventional flow notation) and use our
pens to change the directions
of all the current arrows so as
to point the "correct" way! His
preference was not arbitrary,
though. In his 20-year career as a U.S. Navy electronics
technician, he worked on a lot
of vacuum-tube equipment.
Before the advent of
semiconductor components
like transistors, devices known as vacuum tubes or electron
tubes were used to amplify
small electrical signals. These
devices work on the
phenomenon of electrons
hurtling through a vacuum, their rate of flow controlled by
voltages applied between
metal plates and grids placed
within their path, and are best
understood when visualized
using electron flow notation. When I graduated from that
training program, I went back
to my old habit of conventional
flow notation, primarily for the
sake of minimizing confusion
with component symbols, since vacuum tubes are all but
obsolete except in special
applications. Collecting notes
for the writing of this book, I
had full intention of illustrating
it using conventional flow. Years later, when I became a
teacher of electronics, the
curriculum for the program I
was going to teach had
already been established
around the notation of electron flow. Oddly enough, this was
due in part to the legacy of my
first electronics instructor (the
20-year Navy veteran), but
that's another story entirely!
Not wanting to confuse students by teaching
"differently" from the other
instructors, I had to overcome
my habit and get used to
visualizing electron flow
instead of conventional. Because I wanted my book to
be a useful resource for my
students, I begrudgingly
changed plans and illustrated it
with all the arrows pointing
the "correct" way. Oh well, sometimes you just can't win! On a positive note (no pun
intended), I have subsequently
discovered that some students
prefer electron flow notation
when first learning about the
behavior of semiconductive substances. Also, the habit of
visualizing electrons flowing
against the arrows of
polarized device symbols isn't
that difficult to learn, and in
the end I've found that I can follow the operation of a
circuit equally well using
either mode of notation. Still, I
sometimes wonder if it would
all be much easier if we went
back to the source of the confusion -- Ben Franklin's
errant conjecture -- and fixed
the problem there, calling
electrons "positive" and
protons "negative."

Website for electronics

http://www.petervaldivia.com/technology/electricity/resistance-and-ohm-law.php

http://www.clear.rice.edu/elec201/Book/basic_elec.html

http://www.electronicsteacher.com/tutorial/

http://alignment.hep.brandeis.edu/Lab/Tutorial.html

http://informe.com/electronics/electronics_tutorial/

http://www.kpsec.freeuk.com/symbol.htm

http://www.allaboutcircuits.com/vol_1/chpt_1/7.html

http://www.electronicsandyou.com/electronics-basics/diode.html

http://www.kpsec.freeuk.com/components/diode.htm

http://www.rapidtables.com/electric/electrical_symbols.htm

http://www.rapidtables.com/electric/electrical_symbols.htm

http://www.opamp-electronics.com/tutorials/dc_theory.htm

http://www.ikalogic.com/beg_1_res_v_c.php

http://www.ikalogic.com/beg_1_res_v_c.php

http://www.ikalogic.com/beg_1_res_v_c.php

http://www.hobbyprojects.com/tutorial.html

http://www.hobbyprojects.com/tutorial.html

http://www.khazar.com/academics/portal/ucsc/2010fall/danm219/meeting02.php

http://www.hobbyprojects.com/schematics_circuits_symbols.html

http://paulgorman.org/misc/electronics/

http://www.electronics-tutorials.ws/dccircuits/dcp_1.html

http://www.best-microcontroller-projects.com/schematic-symbols.html

http://www.kpsec.freeuk.com/components/tran.htm

http://www.electronics-tutorials.ws/capacitor/cap_2.html

http://www.technologystudent.com/images5/sw5.gif

Resistance: Ohm´s Law

References:
http://www.petervaldivia.com/technology/electricity/resistance-and-ohm-law.php


What is Electrical Resistance?
When electrons flow through a
bulb or another conductor, the
conductor does offers some
obstruction to the current. This
obstruction is called [b]electrical resistance.[/b]

* The longer the conductor
higher the resistance.
* The smaller its area the higher
its resistance

Every material has an electrical
resistance and it is the reason
that the conductor give out
heat when the current passes
through it.

Resistance is a measure of how much an object opposes the passage of electrons. The unit of electrical resistance is the ohm and it is represented by Ω

Every material has Resistance.
Copper has a low resistance
and wood has a high
resistance. For example, a
metre of copper has a
resistance of only 1 Ohm but a metre of wood has a
resistance of 10000000 ohm

We need resistance to reduce
the flow of electrons through a
circuit, so we can build
resistors to behave as Electrical
resistance. On the right, a
resistor used in the electronic industry.

Reading Resistor Values
The resistance of resistors is
indicated using colour-coded
bands on the body of the
resistor. The first three colour
bands indicate the value of the
resistor in Ohms. The first band tells us the first digit, the
second band tell us the second
digit and the third band tell us
the number of zeros

Electronic Symbols

Electronic Symbol

antenna [url=http://img3.imagehyper.com/img.php?id=580949&c=fe2981f1093b267fb3701fbc02c224ce][img]http://img3.imagehyper.com/t/0/0/580/580949-bc2cdb50.gif[/img][/url]

Antenna Coil [url=http://img3.imagehyper.com/img.php?id=581562&c=f98deae3ab52202a673d8276efc4e899][img]http://img3.imagehyper.com/t/0/0/581/581562-3870f46b.jpg[/img][/url]

I.F. (intermidiate frequency) transformer [url=http://img3.imagehyper.com/img.php?id=581655&c=3351c92403eafd4f21662bcfe9ed4488][img]http://img3.imagehyper.com/t/0/0/581/581655-f47bad72.jpg[/img][/url]
Ang I.F. transformer ay makikita nyo sa radyo na may kulay puti, yellow at black.
[url=http://img3.imagehyper.com/img.php?id=595953&c=6d278b468ce26c3b11a9c2fbea9c747f][img]http://img3.imagehyper.com/t/0/0/595/595953-43e2e8da.jpg[/img][/url]kung makikita nyo ang signal ay lumabas na nakuha sa air, or radio station. Ang ginagawa ng if transformer ,tingnan sa picture. Ay pinapaganda nya ang tunog, mula sa 99% clear papunta sa 100% clear, papunta sa speaker at maririnig na natin.


Oscillator
Coil [url=http://img3.imagehyper.com/img.php?id=581658&c=dd92fa9135a444592f31bbc3827b0b24][img]http://img3.imagehyper.com/t/0/0/581/581658-cc929b18.jpg[/img][/url]ang kulay nya ay red.
[url=http://img3.imagehyper.com/img.php?id=595976&c=cd78da80d842540046b2758ed4af0c24][img]http://img3.imagehyper.com/t/0/0/595/595976-e086d803.jpg[/img][/url]

Interstage transformer [url=http://img3.imagehyper.com/img.php?id=581662&c=263454fc4eb825fb2412f2073945e812][img]http://img3.imagehyper.com/t/0/0/581/581662-8c499f61.jpg[/img][/url]

Output transformer [url=http://img3.imagehyper.com/img.php?id=581545&c=80fd30e7e90900614218afe814d66d02][img]http://img3.imagehyper.com/t/0/0/581/581545-2aee7fb0.gif[/img][/url] [url=http://img3.imagehyper.com/img.php?id=581557&c=6e32e0557dbddc6ecf6d5d9f4fbfb11f][img]http://img3.imagehyper.com/t/0/0/581/581557-7f4b80bc.gif[/img][/url]

Resistor [url=http://img3.imagehyper.com/img.php?id=582165&c=6717b00e21e6c0cb0db7a7c8a3111791][img]http://img3.imagehyper.com/t/0/0/582/582165-e2fb57b0.jpg[/img][/url] [url=http://img3.imagehyper.com/img.php?id=582065&c=d55eb1f82749c9e3afe606cad11e9b2e][img]http://img3.imagehyper.com/t/0/0/582/582065-f5ad1850.jpg[/img][/url]


Thermistor [url=http://img3.imagehyper.com/img.php?id=582091&c=15984c340d1b40d46b3997339eef74c6][img]http://img3.imagehyper.com/t/0/0/582/582091-ce0d1229.jpg[/img][/url]


Volume control [url=http://img3.imagehyper.com/img.php?id=582093&c=fe9ed3359eca3b7823a21e4ae599aa13][img]http://img3.imagehyper.com/t/0/0/582/582093-c39fd829.jpg[/img][/url]


Capacitor [url=http://img3.imagehyper.com/img.php?id=582112&c=89d6ecb1d59bb3b2f486eea426a272e4][img]http://img3.imagehyper.com/t/0/0/582/582112-5592208d.jpg[/img][/url][url=http://img3.imagehyper.com/img.php?id=582117&c=56b7b16d53bf7e352286d63b0c88b009][img]http://img3.imagehyper.com/t/0/0/582/582117-a62e4f34.jpg[/img][/url]

Valuable capacitor [url=http://img3.imagehyper.com/img.php?id=582123&c=29463a768c2c1cc18c1c0621dcdadff5][img]http://img3.imagehyper.com/t/0/0/582/582123-5506e798.jpg[/img][/url]


Diode [url=http://img3.imagehyper.com/img.php?id=582127&c=9b5e0550252296336b1d59eb21588d00][img]http://img3.imagehyper.com/t/0/0/582/582127-460f37c2.jpg[/img][/url]

Battery [url=http://img3.imagehyper.com/img.php?id=582129&c=da09d66d6b39c8be26e56c0c8d389173][img]http://img3.imagehyper.com/t/0/0/582/582129-368d4e31.jpg[/img][/url]

Ground

Speaker [url=http://img3.imagehyper.com/img.php?id=582196&c=800ebeae3f372d13c3b9717dcd297fda][img]http://img3.imagehyper.com/t/0/0/582/582196-9a27c66f.jpg[/img][/url]

Wire connected [url=http://img3.imagehyper.com/img.php?id=582207&c=72a99ed23f69c78f053413af0a19ec76][img]http://img3.imagehyper.com/t/0/0/582/582207-fbf5ca3c.gif[/img][/url]

Wire not connected [url=http://img3.imagehyper.com/img.php?id=582216&c=ddd0949c431db61b2a9d1c4d3d2f9368][img]http://img3.imagehyper.com/t/0/0/582/582216-0c35ce22.gif[/img][/url]

Transistor [url=http://img3.imagehyper.com/img.php?id=582225&c=5080dd20ba5dc16edf45fca2b19faede][img]http://img3.imagehyper.com/t/0/0/582/582225-7cb3fc70.jpg[/img][/url][url=http://img3.imagehyper.com/img.php?id=582236&c=05b701d96d36a0f6f855e31c896451d5][img]http://img3.imagehyper.com/t/0/0/582/582236-cc901774.gif[/img][/url]
[url=http://img3.imagehyper.com/img.php?id=582242&c=c30e2918b845e3f5b99002f7bb280d5a][img]http://img3.imagehyper.com/t/0/0/582/582242-3ba0af0d.gif[/img][/url]
Two kinds of transistor
1. NPN
2. PNP


[url=http://img3.imagehyper.com/img.php?id=582277&c=ac09a0895bbc72e19a48ada110247315][img]http://img3.imagehyper.com/t/0/0/582/582277-c014d364.jpg[/img][/url][url=http://img3.imagehyper.com/img.php?id=582280&c=489c1695f3d4e046a0e538d26ddba90e][img]http://img3.imagehyper.com/t/0/0/582/582280-dc26c75e.gif[/img][/url][url=http://img3.imagehyper.com/img.php?id=582301&c=46c8cdb245312dbaad903823a761247f][img]http://img3.imagehyper.com/t/0/0/582/582301-7a843547.gif[/img][/url][url=http://img3.imagehyper.com/img.php?id=582317&c=4cb62fac41f19e6e7ff1bb8ccb73c84d][img]http://img3.imagehyper.com/t/0/0/582/582317-b0359ed3.gif[/img][/url]