Download pdf - Microprocessor controlled ac and dc drives ppt.pptx

7/28/2019 Microprocessor controlled ac and dc drives ppt.pptx

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Presented ByMd Manzar Nezami

Md Mustafa kamal


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A microprocessor is an electronic device thatconsists of millions (or billions) of transistorspacked into one IC.

Its function is to execute instructions in theform of programs, calculate and store itsresults.

Microprocessors are used widely in our

everyday lives.


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P is a complex, powerful device: Able to process huge amounts of data.

Built using transistors etched on silicon die.

Needs external components to support operation.

Microcomputer system support Poperations.


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The microprocessor can be used to performcomplex operations by giving it instructions.

These instructions are called programs.

Programs are loaded into memory, and areexecuted line-by line by the microprocessor.


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Definition: A complete electronic systembuilt around the microprocessor to supportthe microprocessor operation.

May consist of CPU, memory, I/O (disk

drives, keyboard, mouse), system bus, andsupporting circuitry.

CPU as the brain controls actions of allcomponents.


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ROM

Keyboard Mouse HDD

Floppy RAM

CD-ROMSupporting

CircuitryCPU


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Keypad

Memory

Power Supply LCD DisplayCPU


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A P-based system consists of manycomponents: CPU.

Memory.

I/O: disk drives, keyboard, mouse.

System Bus.

Supporting circuitry.

All components communicate using SystemBus.


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Parallel I/O Serial I/OInterrupt

Circuit

Timing CPU Memory

System Bus


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Master of all components.Job:

Get instructions from memory.

Execute instructions.

Perform calculations (may use math co-processor).

Control bus operations.

CPU


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CPU consists of: ALU (Arithmetic/Logic Unit):

Performs arithmetic/ logic computations.

CU (Control Unit): Responsible to retrieve instructions, analyze, then

execute.

Registers:

Fast internal storage.

Used to temporarily store addresses, data, processorstatus.


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Stores instructions and data for CPU. Each memory location given unique address.

CPU refers to address to access.

Types: Read-Only Memory (ROM).

Random-Access Memory (RAM).

Non-Volatile Memory (NVM).

Memory


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Synchronizes all components in the system. All components refer to the clock timing for

operations.

Generates square waves at constantintervals.

Crystal oscillator + timing circuitry.

Higher clock speed allow computers to

function faster.

Timing


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Input/Output. Connects P with external devices:

Add functionality to P.

Interfaces with P using ports. Examples:

Keyboard.

Mouse.

Display monitor.


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Built into board

Using card slots.


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An electric motor together with its control equipment and energy

transmitting device forms an Electric Drives. Some examples of electric-

drive systems are: A ceiling fan motor with regulator and also with blades,

a food mixer with food to be processed, a motor and conveyer belt with

material on its belt and so on.

Electric drives are mainly two types:-

DC Drives

AC drives


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AC drives are those in which motive power provided by acmotors. Though speed control of dc motors is easy as

compared to ac motors, but ac motors have some advantages

which outweighed the advantages of dc motors, and so with

the development of different techniques of speed control of acmotor drives, now days, ac motor drives are more extensivelyuse in industries.


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Low maintenance cost.

AC drives have a better power factor in most

applications.

Harmonics reduction is cheaper in case of ACdrives.

Higher transient response capability.

AC drives are of lower cost in comparison toDC drives.


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High braking cost.

Complex braking strategy.

Complex and expensive speed control

technique.

Problem of switching losses.

High insulation cost.


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