Technologies For All: May 2015

Monday, 11 May 2015

WHAT IS ELECTROPLATING AND POLARIZATION

Electroplating: Electroplating uses the principle of electrolysis to apply a thin coat of one metal to another metal. Some practical applications include the tinplating of steel, silver-plating of nickel alloys and chromium-plating of steel. If two copper electrodes connected to a battery are placed in a beaker containing copper sulphate...

DEFINE MAGNETIC FLUX AND MAGNETIC FLUX DENSITY

Magnetic flux: Magnetic flux is the amount of magnetic field (or the number of lines of force) produced by a magnetic source. The symbol for magnetic flux is Φ (Greek letter ‘phi’). The unit of magnetic flux is the weber, Wb. Magnetic Flux density: Magnetic flux density is the amount of flux passing through a defined(specific)...

Sunday, 10 May 2015

DEFINE CONDUCTORS,INSULATORS AND SEMI-CONDUCTORS

Some materials allow electric current to flow more freely than others. These materials are called conductors. Other materials are resistant to the flow of electric current. These materials are called insulators. Conductors and insulators are both important in the field of electronics. Conductors: Conductors allow electric current...

DEFINE OHMS LAW

One of the most important and basic laws of electrical circuits is Ohm's law which states that the current passing through a conductor is proportional to the voltage over the resistance. Equation Of Ohms Law: Ohm's law may sound a bit confusing when written in words, but it can be described by the simple formula: I=V/R where I =...

DEFINE RESISTORS,CAPACITORS & INDUCTORS

The three basic elements used in electronic circuits are the resistor, capacitor, and inductor. They each play an important role in how an electronic circuit behaves. They also have their own standard symbols and units of measurement. Resistors: A resistor represents a given amount of resistance in a circuit. Resistance is a measure...

Saturday, 9 May 2015

DEFINE CIRCUIT LOADS

Circuit Loads: A load generally refers to a component or a piece of equipment connected to the output of an electric circuit. In its fundamental form, the load is represented by any one or a combination of the following: 1.Resistor(R) 2.Inductor(L) 3.Capacitor(C) A load can either be of resistive, inductive or capacitive nature or a...

DEFINE VOLTAGE

Voltage or potential difference between two points in an electric circuit is 1V if 1J (Joule) of energy is expended in transferring 1C of charge between those points. It is generally represented by the symbol same letter, however, it rarely causes any confusion.V and measured in volts (V). Note that the the unit of voltage are both denoted...

DEFINE CURRENT

Current: Current can be defined as the motion of charge through a conducting material. The unit of current is Ampere whilst charge is measured in Coulombs. Definition of an Ampere: “The quantity of total charge that passes through an arbitrary cross section of a conducting material per unit second is defined as an Ampere.” Mathematically,...

DC AMPLIFIERS

Fundamental Specifications: The fundamental specifications of dc amplifiers are as follows: - input/output signal range, - offset and offset drift, - single or balanced supply, - input bias current, - open loop gain, - integral linearity, - voltage and current noise. DC Amplifier: As shown...

AC AMPLIFIERS

AC Amplifiers: Altering of a voltage or current signal size as it is passed through a system is called an amplitude control.An amplifier is a circuit for the amplitude control provision. Except for early relatively inefficient electromechanical amplifiers, electronic amplifier development started with the invention of the vacuum tube.Classes...

Thursday, 7 May 2015

WHAT IS THYRISTOR ?

Thyristors: Thyristor name is derived from the Greek “thyra” and means “door”, that is allowing something to pass through. The main group of thyristors is composed by SCR, and others are the special-purpose devices. Structure: A silicon-controlled rectifier (SCR) consists of a four-layer silicon wafer with three pn junctions. It...

DEFINE TRANSISTORS

Transistors: A transistor regulates current or voltage flow and acts as a switch or gate for electronic signals. A transistor consists of three layers of a semiconductor material, each capable of carrying a current. A semiconductor is a material such as germanium and silicon that conducts electricity in a "semi-enthusiastic" way....

Wednesday, 6 May 2015

DEFINE ZENER DIODE

Zener diode: A Zener diode sometimes called breakdown diode or stabilitrone,is designed to operate in the reverse breakdown, or Zener, region, beyond the peak inverse voltage rating of normal diodes. This reverse breakdown voltage is called the Zener or, reference voltage, which can range between –2,4 V and –200 V (Fig. 1.12)....

POWER DIODE AND ITS CHARACTERISTICS

Power Diode: A power diode is more complicated in structure and operational characteristics than the small-signal diode. It is a two-terminal semiconductor device with a relatively large single pn junction, which consists of a two-layer silicon wafer attached to a substantial copper base. The base acts as a heat sink, a support...

DEFINE BIASING ?

Biasing: Fig. 1.5 shows a dc source (battery) across a pn junction. The negative source terminal is connected to the n-type material, and the positive terminal is connected to the p-type material. Applying an external voltage to overcome the barrier potential is called the forward bias.If the applied voltage is greater than the...

WHAT IS PN JUNCTION ?

PN Junction: When a manufacturer dopes a crystal so that one half of it is p-type and the other half is n-type, something new occurs. The area between p-type and n-type is called a pn junction.To form the pn junction of semiconductor, an n-type region of the silicon crystal must be adjacent to or abuts...

DEFINE DOPING

Doping: One way to raise conductivity is by doping.This means adding impurity atoms to a pure tetravalent crystal (intrinsic crystal). A doped material is called an extrinsic semiconductor.Impurity atoms added to the semiconductor change the thermal equilibrium density of electrons and holes....

TYPES OF SEMI-CONDUCTOR DEVICES

Intrinsic Semiconductors. The density of free carriers defines the conductivity of semiconductors as an intermediate between that of insulators and conductors. As mentioned above, the density of free carriers of metals and insulators is approximately constant. This is exact opposite for semiconductors, where the free carrier density...

Subscribe to: Posts (Atom)