2. SEMICONDUCTOR DIODES
The symbol used for a semiconductor diode in
a circuit diagram specifies the type of diode.
There are alternative symbols for some types
of diodes, though the differences are minor.
The triangle in the symbols points to the
forward direction.
3. metal migrates into the
semiconductor3
POINT-CONTACT DIODE
4 The 1N34 germanium
version is still used
2 Metal wire is placed in
contact
1 its construction is simpler
4. P-N JUNCTION DIODE
1 It is made of a crystal
of semiconductor
2
3
4 no charge carriers are
present
5
The junction does not
allow the flow of
electrons
germanium and gallium arsenide are
used
Impurities are added to it to create a region
5. TYPES OF SEMICONDUCTOR DIODES
It consist of thin
sharpened wire
Cat's whisker
diodes were also
called as diodes
Crystal diode
These are type of
point-contact
diode
Tunnel diode
Region of
operation showing
negative resistance
It is caused by
quantum
tunneling
They are used in
spacecraft.
12. POWER CONVERSION AC TO DC POWER SUPPLY
Rectifiers are
constructed from diodes
1
Ex: Automotive Alternators2
Provides better
performance than
commutator or dynamo
3
