06-10-2012, 10:29 AM
VOCATIONAL TRAINING IN BSL,BOKARO
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Electro Technical Laboratory (ETL)
Introduction
1. Electronic devices are the backbone of the electronic industry.
2. Almost everything from children’s toys to life saving equipment
depends upon these components. 3. Billions of components are available in the market.
4. In a large process industry like ours, a wide variety of components are used in various electronic systems.
Types:
• Passive components: Fixed and variable resistances, fixed and variable capacitors, inductors etc.
• Active Components:
1. Vacuum Tube Devices: Diodes, Triodes, Pentodes etc.
2. Solid state device:
• Discrete Devices: Diodes, Transistors, Thyristors, Field Effect Transistors, UJTs,etc.
• Integrated Circuits: Linear ICs, Digital ICs, etc.
Applications:
Capacitor is a very versatile component with widespread applications for example:
• Spark suppression on thermostats, relays etc;
• Reservoir and Smoothing filters in power supplies;
• Decoupling and Coupling in amplifiers;
• Tuning elements for multi-vibrators, delay circuits etc;
• Filters and waveform shaping and oscillators.
Diodes:
Definition:
A diode is a two-terminal semiconductor device consisting of a junction of P-type Semiconductor and an n-type semiconductor material such as silicon, germanium, or selenium. The terminal on the p-side is called as anode while that one the n-side is called as cathode. The presence of the junction imparts the unique property to the diode that it allows current to flow from only one direction i.e. Anode to Cathode while it blocks the reverse current. This property of diode is also called rectifying property. The most common function of a diode is to allow an electric current to pass in one direction (called the forward biased condition) and to block it in the opposite direction (the reverse biased condition).
Transistors:
Definition: A transistor is a semiconductor device, commonly used to amplify orSwitch electronic signals. The transistor is the fundamental building block of computers, and all other modern electronic devices. Transistors are packaged individually and are the most common component inside an integrated circuit.
Thyristors:
Definition: The thyristor is a solid-state semiconductor device with four layers of alternating N and P-type material. They act as a switch, conducting when their gate receives a current pulse, and continue to conduct for as long as they are forward biased (that is, as long as the voltage across the device has not reversed).