1. 1
EST 130, Identifying
Active Components
MEC

2. 2
Contents
• Introduction.
• Vaccum Tubes
• Semiconductor PN Junction Diodes.
- Silicon Diodes.
- Germanium Diodes.
• Zener Diodes.
• Bipolar Junction Transistors.
• Field Effect Transistors.
• Integrated Circuits.

3. 3
Electronic Component
• Wikipedia says:
“An electronic component is any basic
discrete device or physical entity in an
electronic system used to affect electrons
or their associated fields”.

4. 4
Electronic Components

5. 5
Active Components
• Tube Devices or Semiconductor Devices.
• Voltage Controlled or Current Controlled.
• Vaccum Tubes, Diodes, Transistors, Field
Effect Transistors, Thyristors, Integrated
Circuits etc.
• Rely on a source of energy usually from a
DC power supply.
• Can inject power into a circuit.
• Capable of amplification.

6. 6
Vaccum Tubes

7. 7
Vaccum Triode
Cathode emits
electrons when
heated by applying
voltage, Anode
collects, flow of
current controlled by
applying voltage to
control gird.

8. 8
Silicon Semiconductor Diodes

9. 9
Silicon Semiconductor Diodes
• 1N 4001
1N means one junction between P-type
and N-type.
400 means serial number of the rectifier.
1 means 1 Ampere current rating.
• BY 127
B means silicon diode
Y means rectifier, 127 is the serial
number.

10. 10
Semiconductor Diodes
BY 126
BY 126
B – Silicon, Y – Rectifier
126 – Serial No.

11. 11
Silicon Semiconductor Diodes
Unidirectional

12. 12
Diode Characteristics
Conducts when forward
biased.
Only leakage current flows
when reverse biased.
Cut in voltages :
Silicon – 0.6 V.
Germanium – 0.2 V.

13. 13
Types of Semiconductor Diodes

14. 14
Germanium Diodes
.
Used for demodulation
in radio receivers.

15. 15
Germanium Diode
• Point Contact Diodes
OA 79*
O means cold cathode (no heating).
A means low current diode.
79 Loctal Lorenz an all-glass wire (fly-leads in
place of pins) subminiatures.
Courtesy:
Mullard–Philips tube designation.
https://en.wikipedia.org/wiki/Mullard%E2%80%
93Philips_tube_designation

16. 16
Types of Semiconductor Diodes

17. 17
Semiconductor Diode Symbols

18. 18
Semiconductor Diode
Forward Bias Reverse Bias

19. 19
A
K

20. 20
Surface Mount Diodes

21. 21
Applications
• In rectifiers/regulated power supplies.
• In wave shaping circuits.
• For surge protection.
• For unidirectional current flow.
• In clampers/voltage multipliers.
• Can construct basic logic gates.

22. 22
Zener Diodes

23. 23
Zener Diodes
Standard Voltage Ratings:
2.2 V, 2.7 V, 3.3 V, 4.7 V, 5.1 V,
5.6 V, 6.8 V, 8.2 V etc @
standard wattage ratings.

24. 24
Zener Diodes

25. 25
Zener Diodes

26. 26
Zener Voltage Regulator
As normal diode under
forward bias.
Normally operated under
reverse bias.
Breaks down under
reverse bias.
In voltage regulators and
limiters, waveshaping
circuits.

27. 27
Zener Diode for
Circuit Protection

28. 28
Bipolar Junction Transistors
• Current Controlled Device.
• Bipolar device.
• Three terminals – Emitter, Base and
Collector.
• PNP and NPN Transistors - Two PN
Junctions.
• Germanium and Silicon transistors.
• Audio Frequency Transistors.
• Radio Frequency Transistors.
• Power Transistors.

29. 29
Silicon NPN Transistors
BC 107 – NPN Transistor
B – Silicon.
C – Audio Frequency Low Power Transistor.
107 – Serial Number, for domestic use.
TO-18 package.

30. 30
Silicon NPN Transistors

31. 31
Silicon NPN Transistors
SL 100 NPN Transistor
Arrow pointed
outwards

32. 32
Silicon PNP Transistor
SK 100 Silicon PNP Transistor
E
E
B
C
Arrow pointed
inwards

33. 33
Transistor Symbols

34. 34
Germanium Transistors
AC 128
A – Germanium.
C – Audio frequency low power .
128 – serial number, domestic use

35. 35
Power Transistors
2N 3055
2N – Two PN Junctions.
3055 – Serial No.
NPN Transistor

36. 36
High Frequency Transistors
BF 194/494:
B – Silicon.
F – High Frequency Low Power.
194 – Serial No.

37. 37
Field Effect Transistors
• Voltage Controlled Device.
• Unipolar Device.
• High Input Impedance.
• Source, Drain Gate and Body/Shield.
• Junction Field Effect Transistor (JFET).
• N Channel and P Channel JFETs.
• Metal Oxide Semiconductor Field Effect
Transistor (MOSFET).
• N Channel and P Channel MOSFETs.

38. 38
Junction Field Effect Transistors
BFW 10, N Channel Junction Field Effect Transistor.

39. 39
Junction Field Effect Transistor

40. 40
MOSFET

41. 41
Applications of Transistors
• In amplifiers and other electronic circuits.
• In oscillator circuits.
• In domestic and industrial equipments.
• In audio frequency and high frequency
circuits.
• In voltage follower circuits.

42. 42
Integrated Circuit Chip
Dual In Line Package, May contain
millions of transistors on a single chip,
Can be Analog or Digital.
Pins numbered
counterclockwise

43. 43
Integrated Circuit Chip
Surface Mount Chip
Single In Line Package

44. 44
Different IC Packages

45. 45
EPROM Memory Chip
Electrically Programmable Read Only Memory
Erased using Ultraviolet Rays through the window.

46. 46
IC on a Bread Board

47. 47
Thank You