OBJECT: - To study the specification and working of LCD TV.
APPARATUS:-LCD Driving IC,LCD Panel,Rectifier,Inverter,Backlight lamp,source driven IC,Gate driven IC.
THEORY:- A liquid crystal display or LCD draws its definition from its name itself. It is combination of two states of matter, the solid and the liquid. LCD uses a liquid crystal to produce a visible image. Liquid crystal displays are super-thin technology display screen that are generally used in laptop computer screen, TVs, cell phones and portable video games. LCD’s technologies allow displays to be much thinner when compared to cathode ray tube (CRT) technology. Liquid crystal display is composed of several layers which include two polarized panel filters and electrodes. LCD technology is used for displaying the image in notebook or some other electronic devices like mini computers. Light is projected from a lens on a layer of liquid crystal. This combination of coloured light with the gray scale image of the crystal (formed as electric current flows through the crystal) forms the coloured image. This image is then displayed on the screen.
OBJECT: To study the specifications and working of a DVD player.
This section of the manual will introduce you about how to operate a DVD player trainer. Different control provided on a typical DVD player trainer is also discussed. Various control provided on a remote control provided with the DVD player trainer also explained in this experiment. Inter connection audio (L) to Red sockets audio to while socket & video to yellow socket by 2mm patch cards.
- Connecting DVD player trainer to a television receiver
- Before connecting DVD player trainer to television receiver make surethat the power supply to the DVD player trainer and The Television receiver is switched off.
- To connect a typical DVD player trainer to the television Receiver audio / video output or RF output or provided to the DVD player trainer is used.
- Connective DVD player trainer and TV Receiver using A/V connection.
OBJECT: To design and test switch mode power supply using ICs.
Apparatus required: Transformer, diodes, capacitor, resistor, 7805 IC.
A switch mode power supply is a circuit that supplies a constant voltage regard of charges in load current. Although voltage regulator can be designed using op-amps, it is quicker and easier to use IC switch mode power supply. Furthermore, IC switch mode power supply are versatile & relativity inexpensive.
Switch mode power supply are commonly used for on – card power supply & laboratory- type power supplies. Almost all power supplies use some type of switch mode power supply IC because switch mode power supply are simple to use, reliable, low in cost and above,all available in a variety of voltage & current rating.Positive switch mode power supply series with screw voltage options:-
The 7800/78Xxseries consist of terminal positive switch mode power supply with seven voltage option these ICs are designed as fixed switch mode power supply.A switch mode circuit is an indispensable, part of the power supply section of any electronics system. The contemporary regulator circuits are almost exclusively based on one or more than one IC’s known as IC switch mode power supply. IC switch mode power supply are available commercially in a variety of voltage, current and regulationSpecific to meet designers need. The IC switch mode being covered include the adjustable output precision switch mode type 723,the three terminal fixed output voltage positive and negative switch mode and the three terminal adjustable output voltage and negative switch mode.
OBJECT To fabricate PCB and testing of electronics circuit on PCB.
Apparatus required :-Base material cutting machine, Soldering machine,driller,UV light source.
Theory: PCB Manufacturing steps
Following are the steps involved in fabrication of PCB.
• Base material cutting
• Through hole plating
• Layer film generation
• Solder resist film generation
• Legend printing film (optional)
Object: To prepare design layout of PCBs using software tools.
Apparatus: Designing software like Tina or Express PCB or CAD system.
Theory: Printed circuit boards are electronic circuits boards created for mounting electronic components on a nonconductive board, and for creating conductive connections between them. The creation of circuit patterns is accomplished using both additive and subtractive methods. The conductive circuit is generally copper, although aluminum, nickel, chrome, and other metals are sometimes used. There are three basic varieties of printed circuit boards: single‐sided, double‐sided, and multilayered.
Object: To study specifications and working of Public Address System.
Apparatus: Microphones, loud speakers and 100W amplifier kit, connecting wires, multimeter.
Theory: A public address system amplifies low level sound to a higher level so that it can be heard by large number of people gathered and at a considerable distance. A basic public address system has input source is a microphone, which pickups low level sound like a human speech. Examples of some other input sources are a cassette player for playback of recorded music, or compact disc player.
→ To study the specifications and working of a Transistor radio (AM & FM) kit and perform measurement on it.
Object: To study the specifications and working of a Transistor radio (AM & FM) kit and perform measurement on it.
Apparatus: AM/FM Radio receiver, millimeter, connecting probes.
Theory: The kit circuit consists of IC Version 2-Band AM/FM Radio Receiver and Tape recorder In AM receiver again there are two bands i.e. medium wave and shortwave. The shortwave frequency range 535 KHz - 1605 KHz. The FM receiver has frequency band width of 88MHz to 108 MHz. The tape recorder, tape transport mechanism and panel controls of tape recorder.
→ To study& plot the characteristic of a light emitting diode (LED), LDR, photovoltaic cell, opto-coupler, Photo Diode, Photo Transistor.
The light emitting diode is an opto electronic device .when forward gased, this diode emits light if a particular colour depending upon the band GAP,LED are made of gallium arsenide (Ga AS),gallium arsenide phosphide (Ga AS P)&gallium phosphide (Ga P).this materialare doped to get N-type & p-type material. When excited the electrons jump to higher energy levels there by giving off energy in the of radiation.
The printed circuit board (PCB) consist of an insulating substrate material with metallic circuitry photo chemically formed upon that substrate.thus PCB provide sufficient mechanical support and necessary electrical connections for an electronic circuit. Inter connections between components are achieved by means of conducting paths (metallic conductor pattern) running on or through the substance called tracks. The electrical connection between a land and components terminals achieved by means of solder joint.
Soldering is the process of joining thin metal plates or wires made of steel copper or brass.It is very commonly used to join wires in electrical work and mount electronic components on a circuit board.The joining material used in soldering is called as soldered or filler rod. An alloy of tin and lead iscommonly used as solder.The flux is used to clean the surface of the plates/wires to be soldered.
The CRO ( cathode ray oscilloscope), often referred to as a “scope”, is the most powerful tool available for measuring electrical quantities associated with electronic circuitry. It is such an important instrument that a thorough understanding of its operations is absolutely essential for any electrical engineer. Although we will be using a Digital Storage Oscilloscope (DSO), it is instructive to cover the basics of the Cathode Ray tube technology since there are many still in industry. The display on the CRO screen is created by an electron beam exciting a phosphor coating on the inside face of the CRT (cathode ray tube).Fig.3.1(a) shows the major parts of a Cathode Ray Tube (CRT).
Components that resists the flow of electricity equally in both directions. The two main important values associated with resistors are their resistance and their power rating. Resistance is measured in Ohms. An Ohm is quite a small measurement for a lot of electrical applications, so the KILO OHM is often used. 1 K Ohm is equal to 1000 Ohm. The other value is power.
→ Calibrate a single phase energy meter by phantom loading at different power factor by Phase shifting transformer and Auto transformer.
Calibration of all instruments is important once it affords the opportunity to check the instrument against a known standard and to find error and accuracy. Polyphase or 3-phase energy meters in a ‘n’ conductors system requires (n-1) measuring elements for measurement of total energy. Thus a 3-phase 4 wire system requires a 3 element energy system. Polyphase energy meters may be multidisc type each element divides a separate disc. In the single disc type meter all elements drive the same disc.