Author : Debashis De. Contents of the book: Chapter 1: Semiconductor Fundamentals. Chapter 2: Diode Fundamentals. Chapter 3: Diode Circuits. Chapter 4: BJT Fundamentals.
Chapter 5: BJT Circuits. Chapter 6: Field-Effect Transistor. Chapter 7: FET Circuits. Chapter 8: Special Semiconductor Devices. Chapter 9: Feedback Amplifier. Chapter Fundamentals of Integrated Circuit Fabrication. Chapter Operational Amplifier. Chapter Oscillators.
Chapter Digital Electronic Principles. Chapter Electronic Instruments. Click here to download Wait You will be directed to the download link after the count has ended. Books Electronic. You may like these posts. Post a Comment 11 Comments. Tttt April 29, at PM. Lewis May 5, at AM. James Anderson May 10, at AM.
Peter January 5, at AM. Lewis January 21, at AM. James Anderson February 9, at AM. Unknown March 18, at AM. Alia parker September 5, at PM. Conventional current flow is in the direction of positive charge movement from positive to negative. An electric current of one Electron flow is in the opposite direction from negative to positive. The arrow ampere flows in a circuit in a circuit specifies the direction of positive current flow.
But in a liquid or a gas, both the positive protons and negative electrons move to produce a current flow. Since electric circuits consist almost entirely of solid metal conductors such as copper wire, only negatively charged electrons produce a current flow. Current is also a measure of how intense or concentrated the electron flow is. Then a charged particle has the ability to do work. The ability of a charged particle to do work is called an electric potential.
Thus two dissimilar charges have a difference of potential and the unit of potential difference pd is called the volt. The volt unit of potential difference, named after Alessandro Volta — , involves work which is the measure of the amount of work required to move an electric charge, which in turn involves force and distance.
The SI unit of work is the joule with unit symbol J, the SI unit of force is the newton with unit symbol N, and the SI unit for distance is the meter with unit symbol m. Potential energy, which is the energy a body has because of its physical position. Sometimes the symbol U or E for emf electromotive force is used, but the standard symbol V represents any potential difference. This applies either to the voltage generated by a source such as a battery or solar cell, or to the voltage dropped across a passive component such as a resistor.
The voltage difference also called potential difference between two points is the work in joules required to move one coulomb of charge from one point to the other. A voltage source such as The potential difference an alternator or generator provides an alternating AC voltage, so for example between two points is VAC.
The one coulomb of charge difference between the two points is the voltage polarity. The item which provides a path for the electrons to flow is called a conductor. If it points from a more negative to a more VR R positive potential, then the numerical value receives a minus sign, -6V.
Such alternating currents are produced by generators and other such voltage sources whose polarities alternate between a positive direction and a negative direction rather than being fixed in a constant direction as with DC sources.
By convention, alternating currents are called AC currents and alternating voltages are called AC voltages. The most common AC source is the commercial AC power system that supplies energy to your home. The variation of an AC voltage or an AC current over time is called a waveform.
Since these waveforms vary with time, AC supplies are designated by lowercase letters v t for voltage, and i t for current instead of uppercase letters V and I for DC values. Note that the subscript t represents time.
There are many different types and shapes of waveforms but the most fundamental is the sine wave also called sinusoid. The sine wave or Sinusoidal waveforms are sinusoidal AC waveform is the voltage and current waveform shape at the wall produced by rotating a coil socket outlets in your home.
One complete variation between the same points on the waveform is referred to as a cycle. Since the waveform repeats itself at regular intervals over time, it is called a periodic waveform. S, Form Factor and Crest Factor can be use with any type of periodic waveform including Triangular, Square, Sawtoothed or any other irregular or complex voltage or current waveform shape. For a pure sinusoidal waveform the effective or R. The RMS value for a sinusoidal waveform is always greater than its Average value.
The sine wave function is periodic in time. This means that the instantaneous value at time t will be exactly the same at a later time. The time taken by the alternating waveform to complete one full cycle is known as its time period An Alternating Current also called wavelength in radio , denoted by T seconds. AC waveform is defined as one which changes The number of cycles per second of a waveform is defined as its frequency. T The advantage of using alternating voltages and currents for electronic power supplies is that they can be raised and lowered with the help of a device called a transformer.
In DC circuits, raising and lowering voltages is not so easy because transformers cannot be used with direct current. There are also square waves, asymmetrical triangle, rectangular and complex waveforms. Complex waveforms generally consist of base fundamental waveform plus various harmonics superimposed on top. The exact appearance of a complex waveform will depend on the frequencies, magnitudes, and phase relationships of the voltage waves superimposed upon the fundamental wave.
Note that the terms wave and waveform do not refer to the same thing as a wave is a varying voltage or current, but a waveform is a graphical representation of such a varying voltage or current.
Resistance, R of a circuit is its ability to resist or prevent the flow of current electron flow through itself making it necessary to apply a greater voltage to the electrical circuit to cause the current to flow again. Resistance opposes current flow. The amount of resistance a circuit element has determines whether the element is a "good conductor" with low resistance, or a "bad conductor" insulator with high resistance or somewhere in between. Low resistance, for example one ohm or less implies that the circuit is a good conductor made from materials with lots of free electrons in its valence shell.
Examples of good conductors are generally metals such as copper, Resistance is the opposition aluminium, gold, silver or non-metals such as carbon, mercury and some to current flowing around acids and salts. The unit of resistance is the High resistance, one mega-ohm or more implies the circuit is a bad Ohm conductor of electricity made from insulating materials with no free electrons, or tightly grouped electrons in its valence shell.
Examples of insulators include glass, porcelain, rubber, pvc polyvinyl chloride plastics, mineral oils and dry wood or paper, etc. Copper Cable Insulator Conductor 2.
A conductor is said to have a resistance of one ohm when one volt causes one ampere of current to flow through it. Length of Material: The resistance of a material is directly proportional to its length. The longer the material the more resistance it has. Cross-sectional Area: The resistance of a material is indirectly proportional to its width. The wider or thicker the material is the less resistance it has allowing more free electrons to flow.
Type of Material: The type of material affects the amount of free electrons able to flow through it. A material which is a conductor has less resistance while a material which is an insulator has more resistance. Temperature: The temperature of the material affects its resistance. Some materials such as thermocouples and thermistors are design to change their resistance with temperature. The resistor is the simplest passive element used in Electrical and Electronic circuits that is they contain no source of power or amplification but only attenuate or reduce the voltage or current signal passing through them.
A resistor can either be fixed or variable. Most resistors are of the fixed type, meaning their resistance remains constant. Variable resistors, called potentiometers or rheostats can be either linear or logarithmic types having an adjustable resistance value from zero ohms to their maximum resistance. Georg Ohm found that, at a constant temperature, the electrical current flowing through a fixed linear resistance is directly proportional to the voltage applied across it, and also inversely proportional to the resistance.
This relationship between the Voltage, Current and Resistance forms the bases of Ohms Law and is shown below. Ohms Law is used extensively in electronics formulas and calculations so it is "very important to understand and accurately remember these formulas". Linear resistors have a constant resistance for all values of positive or negative voltages and currents.
This linear relationship gives a current-voltage I-V characteristic of a straight line. One watt of power is equal to the work done in one second by one volt of potential difference in moving one coulomb of charge around a circuit. If more heat is generated by the resistor than can be dissipated, the resistor will overheat and become damaged. Resistor power rating is specified in watts. When calculating the power in resistors or resistances, the main equation to use whenever there is current flowing in 2 the resistance is I R.
The physical size of a resistor is no indication of its resistance as a small resistor can have a very low or a very high resistance value. A resistors physical size, however, does give some indication of its power rating.
Whenever current flows Generally speaking the larger their physical size the higher its wattage rating. When resistors with electrical power in Watts higher wattage ratings are required, wirewound resistors fitted to metal heatsinks are generally used to dissipate the excessive heat.
When selecting the appropriate resistor for a circuit, always try to select a resistor with a higher wattage rating than the actual calculated power dissipation for safety reasons as resistors that conduct lots of current can become very hot.
These coloured painted bands produce a system of identification generally known as a Resistors Colour Code. These coloured bands are usually printed towards one end of the resistors body to indicate the first digit with the colours being read from left to right.
In the four-band system, the first band closest to the edge represents the first digit of the resistance value, the second band is the second digit, the third band is the decimal multiplier, which tells us how many zeros to add after the first two digits and the fourth band is the tolerance giving Digit, Digit, Multiplier, Tolerance. The five-band system displays the coloured bands the same as for the four-band, except for an additional third coloured band to represent a third significant digit giving, Digit, Digit, Digit, Multiplier, Tolerance.
The five-band system is used for high precision resistors with low tolerance. These resistive networks have an equivalent resistance which is a combination of the individual resistors. It makes no matter what the combination or complexity of the resistor network is, all resistors obey the same basic rules defined by Ohm's Law above. Since all the current flowing through the first resistor has no other way to go it must also pass through the second resistor and the third and so on. Resistors in series have a Common Current flowing through them as the current that flows through one resistor must also flow through the others as it can only take one path.
Unlike the previous series circuit, in a parallel resistor network the current can take more than one path. Electronics Soft4led. Basic electronics covers common electronic components and their circuits.
If you want to learn electronics in a simple way this app will be helpful to you. It contains a detail explanation of each electronics component. Brush up before taking the electronics exam.
0コメント