COMPUTER COMPONENTS
Roshan Yadav (023A119)
I/O Devices.
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Input Devices provide a medium to feed in data to the computer system.
→ Need of Input Devices
enable computer operators to have control of the computer and
send data to the computer.
translate the information provided by the user into data that is
readable by the computer.
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Output Devices display the processed data in the human readable form.
→ Need of Output Devices
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Receive information to our data given to the computer.
Convert data from low level language(machine understandable) to high level language(human
understandable).
References:
Some devices work as both Input
and output devices
https://etipsguruji.com/
https://www.easeus.com/
Storage
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Device of computer system to save data for future use.
Primary Storage Devices
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Stores the frequently used data.
Very quick Data transfer.
Examples: RAM, ROM, Cach.
Secondary Storage Devices
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Permanently store data and information.
storage of non-critical data in lower-performing, less expensive drives.
(Some)Removable and portable storage used for high speed capacity, cheaper.
Examples: HHD, SSD, Pen Drives, Cloud Storage
Reference: www.verizon.com/ , www.techopedia.com
Embedded Devices
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An embedded system is a small computer that forms part of a
larger system, device or machine. Example:Digital camera, Digital watches, MP3 players etc
Benefits
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Solve specific problems at a faster rate.
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require less power and processing power.
Easy for mass production.
Drawbacks
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It has no technological improvement.
Hard to take backup of embedded files.
Low memory.
Reference: www.geeksforgeeks.org
www.bbc.co.uk
Buffer
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A region of a physical memory storage used to temporarily store data while it is being moved
from one place to another.
Need of buffer
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It helps in matching speed between two devices, between
which the data is transmitted.
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Helps computers to manipulate data data before sending or receiving.
Preventing loss of data.
Reduce amount of data traffic.
References:
https://www.geeksforgeeks.org/
www.javatpoint.com
Difference Between RAM and ROM
RAM(Random Access Memory)
ROM (Read Only Memory)
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Store data temporarily.
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Store data permanently/ unless the data
is altered
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Stores frequently used data.
Ex: Operating system, currently running
applications.
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Stores data required by the system to
function. Ex:BIOS, Bootstrap.
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information is stored electronically on
transistors
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The memory does not depend on an
electric current to save data
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RAM is used in every computing device.
Ex: PC, Smart TV, Mobile phone, Servers.
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ROM is used in Computers, Smart
phones, Digital speed meter.
References: https://www.indeed.com/
https://www.crucial.com/
DIfference between DRAM and SRAM
DRAM (Dynamic Random Access Memory)
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SRAM ( Static Random Access Memory)
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consists of a number of transistors and
capacitors
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uses flip-flops to hold each bit of
memory
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has a higher memory capacity than
SRAM
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has a faster data access time than
DRAM
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consumes more power than SRAM
under reasonable levels of access, as it
needs to be constantly refreshed
Used in servers, workstations, PC,
devices that require low cost high
capacity memory etc.
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if accessed at a high frequency, power
usage can exceed that of DRAM
Used in cache memory, router buffer,
hard disk buffer etc.
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Difference between PROM, EPROM and EEPROM
PROM(Programmable Read
Only Memory)
EPROM (Electronically
Programmable Read Only
Memory)
EEPROM(Electrically Erasable
Programmable Read Only
Memory)
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A ROM that can be
modified only once.
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A programmable that
can be erased and
reused
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A used modifiable ROM
that can be erased and
reprogrammed
repeatedly
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Developed by Wen
Tsing Chow (1956)
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Developed by Dov
Frohman
(1971)
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Developed by George
Perlegos(1978)
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Reprogrammable one
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Reprogrammable using
UV light
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Reprogrammable by
passing electric current.
Working of Laser printer
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The data for the computer is sent to the printer driver.
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The driver ensures that the format is compatible with the printer.
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The charger charges the OPC drum surface with negative charge
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The laser positively charges the part of the OPC drum where the picture to be printed
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The toner from the delivery roller gets attached to the positively charged surface.
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The transfer roller underneath the paper pulls the positively
charged toner onto the paper
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The heat roller presses the toner to the paper with heat
and pressure.
Reference
https://youtu.be/tDiHTK9nwYw?t=92
Working of Speaker
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The binary data of the sound is converted into electrical signal through DAC
The signal is amplified and sent to the speaker.
The electrical signal then runs through the coil wrapped around a iron core producing a
electromagnet which is near to a permanent magnet
The variation in the electric signal varies the magnetic force of the electromagnet which is then
pulled towards the permanent magnet causing the core to vibrate which in turn the vibrates the
cone..
Reference
https://youtu.be/RxdFP31QYAg?t=6 , Hodder publication book
Working of 3D Printer
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The 3D printer software scans the 3D model and brakes it to different segments.
The fragmented design is the sent to the printer.
The print head moves 3 dimensionally and prints the fragmented part of the model onto the
printing plate
The printing plate then moves down and the head prints the another layer.
Reference
https://youtu.be/qoBU0r7pT84?t=7
Working of microphone
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The diaphragm picks up the sound from the surrounding and vibrates
The vibration allows the copper coil wrapped around permanent magnet to move backwards
and forwards.
This induces an analog electric current
The signal is sent to the computer to be recorded.
Reference
https://youtu.be/vRmEeNNXSfk?t=20
Working of Magnetic Hard Disk
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The Data sent after processing is stored on a disk platter which spins at a speed of 7000 rpm.
The data is stored in sectors and tracks.
The arm fixed on top of an actuator moves 50 time a second reading and writing data.
For reading the platter storing 0 and 1 sends tiny electrical current through the arm which
allows it to distinguish.
For writing the computer sends tiny electrical current which flips the polarities of the parts of
platter.
Reference
https://youtu.be/wteUW2sL7bc?t=24
Working of Solid State Drive
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The datas are stored in a microchip.
Inside this microchip the data is stored in Charge trap flash in from of electrons.
The trap can store the electrons for years without loss of data.
When rewriting the electrons are forced out of the trap making space for new memory.
For reading and writing control gate selectors are used along the layers and bitline selectors
are used along the rows.
Reference
https://youtu.be/E7Up7VuFd8A?t=23
Working of Optical Disc Reader
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The data in an Optical Disc is stored in pits and bumps
The disc is rotated quickly and a laser is used to read/write data.
When a laser incidents onto bumps its reflective surface reflects it and a light detector
catches it as 1 and when the laser incidents onto pits it does not reflect indicating a 0
To increase storage disc dual layering is used by placing a reflective flat surface between two
consecutive storage area.
Reference
https://youtu.be/CGER86jzWXw?t=111
Working of touchscreen
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Touch screens are of 2 types , resistive and capacitive.
Capacitive touchscreen have 2 layer of charged layers that form a grid when placed together
When a small electric charge is discharged from a human body when touching the screen the
layers respond to the touch and send a signal to the microprocessor on implementing the
touch.
Resistive touchscreens have a charged layer of glass
which is topped by a plastic layer leaving a small space
in between
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When pressure in created at a certain point of plastic
the circuit is completed at the charged layer to which
the computer software respond to.
Reference
https://www.youtube.com/watch?v=IdWXT391FJE&t=73s
Working of Virtual Reality Headset
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The headset is connected to a screen or a smartphone from where it takes inputs.
The screens are divided into 2 to simulate the vision of human eyes.
When a person moves their head then the movement is calculated and the 3D environment
inside the virtual reality also moves accordingly.
Most headsets use 110° field of view which is enough to give a false 360° surround
image/video.
Reference: Hodder publication book
Monitoring and Control System
Monitoring
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Monitoring system are kept in place to observe the state of the environment and generate an
output according to the observation.
Control system
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Control systems automatically detect the environment
change and perform changes to the device according
to its preset values.
Reference
https://learnlearn.uk/
Difference between Monitoring and Control
system
Monitoring System
Control system
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Observes environment using sensors and
process it to produce an output
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Observes environment and automatically
change the state of the environment.
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Usually alerts the user if changes occur
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Usually changes the environment on the basis
of it preset values.
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Actuators are not used
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Actuators are used
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Used in Radar systems, Burglar alarms, Smoke
detectors.
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Used in Air conditioning system, Heating
system
Reference
https://learnlearn.uk/
Sensors
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Sensors detect changes in the environment in form of analog signals.
The analog data is sent to the computer to process.
The analog signal from the sensors are changed to digital signals through DAC which is then
process in a computer
There are different types of sensors
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Temperature
Sound
light/infrared
Pressure
Accelerometer
Gas
Moisture
Vibration
Reference
https://learnlearn.uk/
Uses Of some Sensors
Sensors
Temperature
Uses
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Control/monitor temperature in a
greenhouse
Control a central heating system
Light
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Street light system
Switch on car lights when it gets dark
Sound
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Burglar system
Detect dripping of water from a pipe
Gas
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Detect the presence of harmful gases
Monitor pollution level
Infrared
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Burglar system
Automatic lighting system.
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Actuator
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Electromechanical devices used to convert electrical energy into some sort of automatic
mechanical action.
Actuators need analog signal to work so sometimes the digital signals are again converted
into analog signals using DAC
Uses of Actuators
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Operate valves
Drive motors / conveyer belt
Switches
Reference
https://learnlearn.uk/
Feedback
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When the output from a control system is again fed back in the system as an input then it is
called feedback.
There are 2 types of feedback: Positive feedback , Negative feedback
Importance of Feedback
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Reduce error
Increases efficiency, accuracy and quality
Alter the next input of the control system
It helps identify problems with the system
Reference:
https://www.tutorialspoint.com/
https://www.wharftt.com/