 |
Useful Links |
|
|
Indian
Scientists
SerialCommunication
Datasheets
8051
Tutorial
555 Timer Tutorial
Calculators
Delays
BEAM
ROBOTICS
WiMAX
Sensors
MP3 VS MP4
Pocket PC
Chandrayaan
DIAC TRIAC
6Sigma Methodology
Electronics Teacher
ALBERT EINSTEIN
Biography and inventions
123Circuits.com
Electronics terms
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z
EMS
TRACKING:TRACK YOUR COURIERS
|
|
Electronics Tutorial for Beginners
ABC of Electronics Offering free comprehensive basic
electronics tutorial. In this Electronics Tutorial we
have explained the basic electronic concepts. Here you
can find 8051 Tutorials & 555 Timer Tutorials which are
commonly used in electronics.
Every effort is made
to keep the website up and running smoothly |
Capacitors Tutorial
Capacitors
Basics

The capacitor's work is to
store electricity, or electrical energy, it works similar to battery. The capacitor is also used as a
filter,
allowing alternating current (AC), and
disallowing direct current (DC). A capacitor is
also an
electronic component that stores energy in the form of an electrostatic field.
Capacitor consists of two conducting plates Between these
plates there is
an insulating material called the dielectric. .When we apply to capacitor DC
voltage an electric charge is stored in plates. The value of a capacitor is designated in units
called the Farad ( F ). The capacitance of a capacitor is very small, hence it is
designated in microfarad ( 10-6F ),
nanofarad ( 10-9F ), and picofarad (10-12F
) units. It store
energy in the
electric field between a
pair of
conductors called "plates"

How to Calculate Total Value of
Capacitors?
To compute the total value
of capacitors in parallel that are connected across each
other we will add their values and in order to find the total value if they are in series that is in
line with each other then use the following formula 1/C
total =1/C1 + 1/C2 + 1/C3 .
Capacitors are also referred to as condensers.
Note:DC current cannot
flow through a capacitor because the dielectric forms an
open circuit
The capacitor's capacitance (C)
is a measure of the amount of charge (Q) stored on each plate for a given
potential difference or voltage (V) which appears between the
plates:
C=Q/V
The capacitance is directly
proportional to the surface areas of the plates, and is inversely proportional
to the separation between the plates. Capacitance also depends on the dielectric
constant of the substance between the electrode plates.
Capacitor Types and usage
Capacitors can be used to
control timing, filtering out power supplies. Four major types of
capacitors are ceramic, electrolytic, and tantalum

1) Ceramic
capacitors are small in size and value, ranges from Pico Farads to 1 µF.
Not polarized, so either end can go to ground. Value is given by a code like we
in
resistors.

2)
Electrolytic capacitors look like small cylinders and range in value from 1 µF
to several Farads. Its value is changed as the electrolytic
ages. Polarized, cathode must go to ground. Cathode is assigned with a minus
sign on case. Value is usually written on case.

3)
Tantalum capacitors are similar in size to ceramic but can hold more charge, up
to several hundred µF. Stable and correct, but comparatively expensive.
Usually Polarized, anode is assigned with a plus sign.

4)Variable Capacitors are also called Tuning Capacitors. They
have very small capacitance values, between 100pF and 500pF (100pF = 0.0001µF).
Units of Capacitance
Microfarad (μF) 1μF = 1/1,000,000 = 0.000001 = 10-6 F
Nanofarad (nF) 1nF = 1/1,000,000,000 = 0.000000001 = 10-9 F
Picofarad (pF) 1pF = 1/1,000,000,000,000 = 0.000000000001 = 10-12 F
Capacitors Color Codes
| Colour |
Digit A |
Digit B |
Multiplier D |
Tolerance T > 10pf |
Tolerance T < 10pf |
Temperature
Coefficient TC |
Working voltage V |
| Black |
0 |
0 |
x1 |
± 20% |
± 2.0pF |
|
|
| Brown |
1 |
1 |
x10 |
± 1% |
± 0.1pF |
-33x10-6 |
|
| Red |
2 |
2 |
x100 |
± 2% |
± 0.25pF |
-75x10-6 |
250v |
| Orange |
3 |
3 |
x1000 |
± 3% |
|
-150x10-6 |
|
| Yellow |
4 |
4 |
x10k |
+100%,-0% |
|
-220x10-6 |
400v |
| Green |
5 |
5 |
x100k |
± 5% |
± 0.5pF |
-330x10-6 |
100v |
| Blue |
6 |
6 |
x1m |
|
|
-470x10-6 |
630v |
| Violet |
7 |
7 |
|
|
|
-750x10-6 |
|
|
Grey |
8 |
8 |
x0.01 |
+80%,-20% |
|
|
|
|
White |
9 |
9 |
x0.1 |
± 10% |
Capacitors Letters Codes
|
|
|
© Copyright 2008, ABC of Electronics. All Rights Reserved.
|
|
|
|
|