Transcript PDEV-1018 AMATEUR RADIO OPERATOR INTRODUCTION

AMATEUR RADIO
OPERATOR
INTRODUCTION
January 2013
Active Devices
Diodes, Transistors, and Tubes
AGENDA
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Diodes
TRANSISTORS/FETS
TUBES
QUESTIONS
SEMICONDUCTORS
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VERY STABLE CRYSTAL STRUCTURE
SILICON & GERMANIUM MOST COMMON
SILCON ATOMS SHARE VALENCE
ELECTRONS (8 ELECTRONS)
CAN BE GOOD INSULATOR
INTRINSIC- PURE MATERIAL, NO FREE
CHARGE CARRIERS
EXTRINSIC – MATERIAL DOPED WITH
EXTRA CARRIERS
DOPING
JUNCTIONS
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N TYPE – EXTRA
ELECTRON (- CHARGE)
P TYPE – MISSING
ELECTRON
(+ CHARGE)
PN JUNCTION
DEPLETION ZONE
DEPLETION ZONE
PN JUNCTION
FORWARD BIAS
DIODES
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2 TERMINAL PN
JUNCTION
ANODE – P
CATHODE - N
Diodes (i-v curves)
Diodes
DIODE APPLICATIONS
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SWITCH
RECTIFICATION
DEMODULATION
REGULATION
LIGHT EMITTING (LED)
RECTIFIERS
ZENER DIODES
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Used to regulate
voltages
Behaves normally when
forward biased
When reversed biased,
non destructive voltage
breakdown
ZENER Voltage
ZENER Regulation
TRANSISTORS
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3 TERMINAL DEVICE
2 JUNCTIONS
P-N-P
N-P-N
ALSO KNOWN AS
“BIPOLAR
TRANSISTOR”
BASE CURRENT
CONTROLS
EMITTER/COLLECTOR
CURRENT
NPN TRANSISTOR
PNP TRANSISTOR
FIELD EFFECT TRANSISTOR
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TWO TYPES
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JUNCTION FIELD EFFECT or JFET
METAL OXIDE SILICON FIELD EFFECT or
MOSFET
A CONDUCTIVE CHANNEL WITH 2
JUNCTIONS
N-CHANNEL
P-CHANNEL
FETS
TRANSISTOR - FET
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EMITTER, BASE,
COLLECTOR
FOR BIAS INCREASES
CURRENT
CURRENT CONTROLS
LOW INPUT Z
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SOURCE, GATE, DRAIN
REV BIAS DECREASES
CURRENT
VOLTAGE CONTROLS
HIGH INPUT Z
VACUUM TUBES
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Developed in late
1800’s and early 1900’s
Still used in
applications requiring
high power or high
voltages (power
amplifiers)
Tube Construction
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Thermionic emission
Filament (Heater) used to heat cathode
Cathode made of tungsten and thorium
Heated cathode emits an electron cloud
Positive potential placed on Plate (Anode) to
attract electrons
Negative potential Grid used to control
electron flow
Vacuum Diode
Vacuum Triode
Tubes – Take Aways
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Grid current – minimal or zero as long as
Grid is negative relative to cathode
Grid is usually a mesh
Grid is closer to cathode
Heater is farthest from Plate
Used in high power applications
Inside of envelope is a vacuum
Tubes, transistors, FETS
Charge
Source
Control
Terminal
Charge
Collector
Control
Tubes
Transistors
FETS
Cathode
Emitter
Source
Grid
Base
Gate
Plate
(Anode)
Collector
Drain
Voltage
Current
Voltage
AMPLIFICATION
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Produce an output which is an enlarged
reproduction of the input.
Device is called an AMPLIFIER
An accurate reproduction is called “LINEAR”
Imperfections in reproduction are called
“DISTORTION”
Tubes, Transistors, and FETs can all be
amplifiers.
Typically gain is measured in dB
Amplifier Applications
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AF (Audio Frequency)
RF (Radio Frequency)
IF (Intermediate Frequency)
PA (Power Amplifier)
Current, Voltage and or Power can all be
amplified
Distortion
Homework
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Review Class Notes and Handouts
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Read ahead for next week
QUESTIONS????
THANK YOU!!!!!!!!