1. Applications of Basic Electronics Components
Nur Liyana Tajul Lile

2. Half-wave rectifier circuit.
rectification is the conversion of alternating current (AC) to direct current (DC)

3. Half-wave rectification is insufficient for most power applications.
The harmonic content of the rectifier's output waveform
is very large
difficult to filter.
half of the rectifier capacity is unused
As the AC power source only supplies power to the load one half every full cycle

4. Half-wave rectification is, however, a very simple way to reduce power to a resistive load.
Some two-position lamp dimmer switches apply full AC power to the lamp filament for “full” brightness and then half-wave rectify it for a lesser light output.

5. Half-wave rectifier application: Two level lamp dimmer.

6. In the “Dim” switch position,
the incandescent lamp receives approximately one-half the power it would normally receive operating on full-wave AC.
the half-wave rectified power pulses far more rapidly than the filament has time to heat up and cool down
the lamp does not blink (on/off)
its filament operates at a lesser temperature than normal
less light output.

7. This principle of “pulsing” power rapidly to a slow-responding load device to control the electrical power sent to it
Since the diode is either fully conducting or fully non-conducting at any given time,
it dissipates little heat energy while controlling load power,
very energy-efficient.

8. Clipper A practical application of a clipper is to
prevent an amplified speech signal from overdriving a radio transmitter
Over driving the transmitter generates
spurious radio signals
interference with other stations.
A sine wave may be squared up by overdriving a clipper
The clipper is a protective measure.

9. Clipper prevents over driving radio transmitter

11. Over-Temperature sensing circuit
To determine when the temperature reaches a certain critical value.
The circuit consist of a Wheatstone bridge with op-amp
used to detect when the bridge is balanced
Thermistor (R1) is a temperature-sensing resistor with a negative temperature coefficient (resistance decreases as temperature increases)

12. At normal temperature (below critical), R1 is greater than R2
Potentiometer R2 is set to a value equal to the resistance of the thermistor at the critical temperature
At normal temperature (below critical), R1 is greater than R2
Unbalanced condition that drives the op-amp to its low saturated output level
Transistor Q1 off.
As temperature increases, resistance of thermistor decreases
When temperature reaches critical value, R1=R2, bridged becomes balanced.
At this point op-amp switches to its high saturated output level, turning Q1 on
Energizes the relay
Activate alarm
An apropriate response to over-temperature condition.

15. Analog-to-Digital Conversion
Common interfacing process when linear analog system must provide inputs to digital system.
The simultaneous, flash method of A/D conversion uses parallel comparators to compare linear input signal with various reference voltages develop by a voltage divider
When input voltage exceeds the reference voltage for a given comparator,
High level is produced at comparator output
Figure below shows analog to digital converter
Produces 3 digit binary numbers on its output
Requires 7 comparators (2n-1)
n-digit binary

16. Used large no of comparators
Priority encoder is a digital device produces a binary number on its output representing the highest value input

18. Electronics, By D. I. Crecraft, David Gorham

19. Electronics, By D. I. Crecraft, David Gorham

20. The ADC is fixed at 10 bits of binary data output,
To measure the height of water in a 40- foot tall storage tank using an instrument with a 10-bit ADC.
0 feet of water in the tank corresponds to 0% of measurement
40 feet of water in the tank corresponds to 100% of measurement.
The ADC is fixed at 10 bits of binary data output,
it will interpret the tank level as one out of possible states.

21. physical water level in each step of the ADC
divide the 40 feet of measurement span by the number of steps in the 0-to-1024 range of possibilities,
which is 1023 (2n-1).
obtain feet per step.

23. Controlling a fan with a thermistor
Thermistor can be used for the fan to come on above a specific temperature.
The diagram below is a circuit which uses an op amp as a comparator
with an output which goes high
when pin 5 goes higher than pin 6.

24. The temperature and voltage on the potentiometer can be changed.
Voltage can be changed based on the potentiometer
This controls the reference voltage on the negative input of the op amp.
Setting it lower makes the fan come on at cooler temperatures.

25. Thermometer is used to change the relative temperature
When the conditions are right, the relay will engage and the fan will run.

28. Bipolar Junction Transistor
Transistor switch

29. Used as a switch to turn the LED on and off
Square wave input voltage with a period of 2s is applied to the input.
When square wave is at 0V, transistor in cutoff.
No Ic
LED does not emit light
When square wave goes to its high level, transistor saturates
Forward bias the LED
Ic through LED
Emits light
LED is on for 1 second and off for 1 second

30. References http://www.allaboutcircuits.com http://www.bcae1.com/
_bridge.htm
Electronics, By D. I. Crecraft, David Gorham

31. In group of 5, select three electronics components and explain their applications.