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PRESENTATION

ON

HANDLING OF PUBLIC ADDRESS EQUIPMENT SYSTEM- LIQUID CRYSTAL

DISPLAY(LCD), STILL CAMERA AND VIDEO CAMERA

INSTRUCTORDr. D. K. MEENARGSC, BHU

SPEAKERNEHA TANDONNISHU KUMARI

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PUBLIC ADDRESS SYSTEM

Public Address (P.A.) systems originated in ancient Greece with the construction of amphitheatres“Public address system is a set of equipments to amplify sound so that it is audible to a large audience over a distance.”Used in extension programmes involving a large number of people such as mass meeting, training programme, field day or farmer’s day, campaign, exhibition etc.

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COMPONENTS OF PUBLIC ADDRESS SYSTEM

A public address system has three components:-

1.MICROPHONE/MIKE/MIC• It is an acoustic-to-electric sensor that converts sound into

an electrical signal. 2.AMPLIFIER/ELECTRONIC AMPLIFIER/AMP• It modulates the output of the power supply to make the

output signal stronger than the input signal.3.LOUDSPEAKER/SPEAKER• It is a device which convert an electrical audio signal into a

corresponding sound.

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COMPONENTS OF A PUBLIC ADDRESS SYSTEM

MICROPHONE

AMPLIFIER

LOUDSPEAKER

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WORKING OF A PUBLIC ADDRESS SYSTEM

The working of the PA system consists of 4 steps:-1.Begins with a sound source (such as a human voice),

which creates waves of sound (acoustical energy). 2.These waves are detected by a microphone, which

converts them to electrical energy. 3.This signal is amplified in an amplifier up to a

required level. 4.The loudspeaker converts the electrical signal back

into sound waves, which are heard by human ears.

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TYPES OF PUBLIC ADDRESS SYSTEM

1.SMALL PA SYSTEMS• Simplest PA systems consisting of a microphone, an

amplifier, and one or more loudspeakers.

2.LARGE PA SYSTEMS• PA systems having speakers that cover an entire campus of

a college or industrial site.

3.LONG LINE PA SYSTEMS• Any PA system across a wide geographic area, larger than in

large PA systems.

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LIQUID CRYSTAL DISPLAY(LCD)

A liquid-crystal display (LCD) is a flat-panel display or electronic visual display.

They produce no light of their ownThey require external light to produce a visible

image provided by backlights provided at the back of the glass.

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LCD PROJECTOR

An LCD projector is a type of video projector for displaying video, images or computer data on a screen or other flat surface

LCD projectors typically send light from a metal-halide lamp through a prism that produces a wide range of colors and shades in the projected image.

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USE OF LCD PROJECTOR IN EXTENSION TEACHING PROGRAMMES

• Essence of a presentation• Brings audio-visual inputs to the programme• Inputs planned elsewhere in the world can be

brought into the programme• Demonstrations• Webinars• Quizzes• Lectures• Group activities

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ADVANTAGES OF USING LCD PROJECTOR

• Low power consumption• Unconstrained by geographical location of

device• Clearer image display• Can incorporate audio and video clips• Easier note taking• Greater teaching versatility• Better use of class time

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THINGS TO BE KEPT IN MIND WHILE USING A LCD PROJECTOR

Will the presentation hold the attention of the audience?

Will it efficiently supplement what he/she is going to present?

Can the audience read the presentations without much delay?

Can the audience listen to the talk of the presenter as well as read the text presented and relate both?

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VIDEO CAMERA

A video camera is camera used to make electronic motion pictures. It captures moving images and synchronous sound.WHY VIDEO CAMERA ?

It is a type of visual communication which use moving pictures and sound to tell stories or inform (help people to learn).

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1. Lens

2. Viewfinder

3. Body

4. Shutter Release

5. Aperture

6. Image Sensor

7. Memory Card

8. LCD Screen

9. Flash

10. User Controls

MAJOR COMPONENT OF VIDEO CAMERA

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STILL VEDIO CAMERAA still video camera is a type of electronic camera that takes still images and stores them as single frames of video.

The best known model’s include Sony Mavica, Canon’s lon and Xapshot cameras.

The most common design has an image sensor and basic processing hardware similar to that of a domestic analog camcorder.

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Canon RC-250 QPIC still video camera

Prototype Sony Mavica still video camera from 1981.

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1. Media

2. Home video

3. Politics 4. In surveillance

5. Entertainment

6. Education

MOSTLY USED FOR

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