2. Active components are those electronic
components which are capable of processing or
amplifying an electrical signal.
Although, there are so many active components used in
electronic circuits, but all the active electronic components
may be classified into two type as under:
Active
Components
Tube Devices
Semiconductor
Devices
5. The term diode denotes a two-electrode device. A
semiconductor diode is simply a P-N junction with connecting
leads or terminals on the two sides of the P-N junction. P-N
junction is also called the crystal diode because the P-N
junction is grown out of crystal.
6. 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.
7. LEDs emit light when an electric current
passes through them.
LEDs are based on the semiconductor
diode. When the diode is forward
biased (switched on), electrons are
able to recombine with holes and
energy is released in the form of light.
This effect is called
electroluminescence and the color of
the light is determined by the energy
gap of the semiconductor.
8.
9.
10. A transistor is a semiconductor device commonly used to
amplify or switch electronic signals.
Device with three terminals where one terminal can be
use to control the flow of current through the other two
terminals.
The three terminals are Emitter, Base and Collector
Transistor are of two types:
n-p-n
A straight switch
p-n-p
A inverted switch
11. When base of n-p-n is connected with logic high voltage then
it short circuit emitter and collector (SWITCH ON).
When base of n-p-n is connected with logic low voltage then
it open circuit both emitter and collector (SWITCH OFF).
When base of p-n-p is connected with logic high voltage
then it open circuit emitter and collector (SWITCH OFF).
When base of p-n-p is connected with logic low voltage
then it short circuit both emitter and collector (SWITCH
ON).
12.
13.
14. A Comparator is a device which compares two
voltages or currents and switches its output to
indicate which is larger.
Comparator is an Op-amp.
PIN DIAGRAM LM 358
15. The 555 Timer IC is an integrated circuit (chip)
implementing a variety of timer applications
PIN DIAGRAM
16. This is used to make the stable voltage of
+5V for circuits. The LM7805 is three
terminal positive
regulators are available in the TO-220 -
package and with several fixed output
voltages, making them
useful in a wide range of applications
