Saturday, August 11, 2012
MAGNETISMThere are several relationships between electricity and magnetism. We will explore them one by one. The first relationship we will discuss is how current flowing through a wire creates a magnetic field. A steady current creates a steady magnetic field like that created by a magnet. Electro-Magnet We can create an electro-magnet by wrapping many turns of wire on a core, then causing an
A boost converter is a DC-to-DC power converter with an output voltage greater than its input voltage. It is a class of switched-mode power supply (SMPS) containing at least two semiconductor switches (a diode and a transistor) and at least one energy storage element, a capacitor or inductor. The boost converter is also called as step-up converter.
Basic schematic of boost converter.
Friday, August 10, 2012
PIR sensors allow you to sense motion, almost always used to detect whether a human has moved in or out of the sensors range.
They are small, inexpensive, low-power, easy to use and don't wear out.
For that reason they are commonly found in appliances and gadgets used in homes or businesses. They are often referred to as PIR, "Passive Infrared", "Pyroelectric",
Here is a microscopic view of electricity. How electrons flow inside the conductors.
Please click the Below Link to view the Animation.
I hope it will give you a better understanding on it.
Animation of Electricity
Earthing is a safety device used to prevent a shock due to leakages arising from weak insulation, breaking of the element or otherwise.
The metal bodies of appliances handled like the electric iron, kettle or refrigerator must be earthed, that is, connected to a pipe leading deep into the earth on to a metal plate.
In case the metal body becomes live, the circuit is completed through the
Artificial neural networks are composed of interconnecting artificial neurons (programming constructs that mimic the properties of biological neurons).
Artificial neural networks may either be used to gain an understanding of biological neural networks, or for solving artificial intelligence problems without necessarily creating a model of a real biological system.
Its true that if birds touch the single one line (phase or neutral) they don't get electrical shock... if birds touch 2 lines then the circuit is closed and they get electrical shock..
so if a human touch single one line(phase) then he doesn't get shock if he is in the air (not touching or standing on the ground).
if he is standing on the ground then touching the line (phase) he will
Since the power factor of transformer is dependent on load we only define VA rating and does not include power factor .
In case of motors, power factor depend on construction and hence rating of motors is in KWatts and include power factor.
Fuses are burned at the time of over current flows in the circuit but breakers are just open(not burn) at the time of over current flow.
Fuses are used in only one time, but breakers are used by multiple number of time
Transformer Induced voltage equation contains 4.44 factor.
E -Induced emf per phase
T -number of turns
phi -maximum flux per pole
From the equation we see that E is proportional to 4.4 and it is in turn multiple of 11.So always transmission voltage is multiple of 11.
Thursday, August 9, 2012
CURRENT is the quantity or flow rate of electrons moving a point within one second. Current flow is also known as amperage, or amps for short.
Higher voltage will produce higher current flow, and lower voltage will produce lower current flow.
Voltage is the electrical force that moves electrons through a conductor.
Voltage is electrical pressure also known as EMF (Electro Motive Force) that pushes electrons.
The greater the difference in electrical potential push (difference between positive and negative), the greater the voltage force potential.
In any DC motor, the speed of the motor is inversely propotional to the flux and directly proportional to Back EMF .
When starting a series motor the current flowing will be high, but the flux that the motor produces will be moderate since the series winding has less number of turns.
Hence, if u start the motor without load the speed will increase.
As speed increases the back emf
What is inside a Transformer?
Transformer works on mutual induction principle. In order to generate an alternating flux, we need alternating current. If we provide DC current to the transformer there is no linkage of flux to secondary winding. DC current will produce only constant magnetic field. So we will not get output from the secondary.
Electric Motor Working
We all know about the supply frequency which is essential for any electrical machinery.
But can we run a motor rated for 50 Hz on a 60 Hz supply, or vice versa?
The relation between the speed of the motor and its frequency is given by the expression
N = 120f/P.
From this expression, it
Wednesday, August 8, 2012
Here is a fantastic animation for the fundamentals of Micro processor.
What are the main components of the Micro Processor?
How a Micro Processor works?
Please click on ANIMATION 1 to view the introduction on Micro Processor.
Please click on ANIMATION 2 to view the detailed animation on working of the Micro Processor
We know that the advancement in the IC technology changed the world and it is the main reason for the portable devices available now-a-days.
First Integrated Chip
In the below animations, you can see what happened in the past years after the first IC has been manufactured.
I have gone through a fantastic Flash Animation of Flip Flops.
Difference between LATCH and FLIP FLOP
I got a clear idea about the difference between LATCH and FLIP FLOP through this animation.
You can learn all the basics of Flip Flops here.
Please CLICK HERE to view the animations
Virtual Ground Analogy
Look at this circuit Diagram.
Virtual ground appears in the common point between two series connected resistors, if
• two voltages are applied to the other ends of the resistors,
• they have opposite polarities,
• they bear the same proportion as between the respective resistors.
Virtual ground phenomenon is summing of opposite equal quantities, which is
The cache memory is defined as the first level of memory after the Registers. In the memory hierarchy, it is placed right below the processor registers as shown in the figure above.
Speed Vs Distance Vs Size of the Memory
The above diagram shows the position of the Cache memory based on the Speed, Distance from the Processor and the Size.
How the Processor check for
Tuesday, August 7, 2012
The above graphic animation illustrates typical operation of an instruction by the processor.
It places the contents of the instruction pointer onto the address bus and fetches the instruction.
Once decoded, the instruction is executed and the instruction pointer altered to point to the next instruction.
Processor or processing unit may contains the following,
Graphics processing Unit
Physics Processing Unit
Digital signal processor
Front end processor
Click the below link to view the working animation
Hardwork Can Never Ever Fails..
First a bit history
In 1870, John Tyndall demonstrated that light follows the curve of a stream of water pouring from a container, it was this simple principle that led to the study and development of applications for this phenomenon.
John Logie Baird patented a method of transmitting light in a glass rod for use in an early colour TV, but the optical losses inherent in the materials at the
What is a decibel, and how is it measured?The decibel (abbreviated dB) is the unit used to measure the intensity of a sound.
The decibel scale is a little odd because the human ear is incredibly sensitive.
Your ears can hear everything from your fingertip brushing lightly over your skin to a loud jet engine.
In terms of power, the sound of the jet engine is about 1,000,000,000,000
Monday, August 6, 2012
What is Latchup?
Latch-up is a condition in which the parasitic components give rise to the Establishment of low
resistance conducting path between VDD and VSS with Disastrous results.
(in the figure, moat = substrate)
The start of trouble!
Electron flow builds up voltage
The forward biased source injects some holes
The holes are swept into the substrate
Nuclear Fission: A nuclear fission is either a nuclear reaction or a radioactive decay process in which the nucleus of an atom splits into smaller parts (lighter nuclei), often producing free neutrons and photons (in the form of gamma rays), and releasing a very large amount of energy, even by the energetic standards of radioactive decay.
click below to view the animation
----A current source is an electrical or electronic
device that delivers or absorbs electric current. A current source is the dual of a voltage source. The term constant-current sink is sometimes used for sources
fed from a negative voltage supply.
----If the current through an ideal current source can be
specified independently of any other variable in a circuit, it is
Hi dear friends click the below link to learn the following things... Really useful...
for example the mass of a proton
Proton mass = 0.00000000000000000000000167 grams
a steady electric current of 1 amp
1 amp = 6,250,000,000,000,000,000 electrons per second
Arithmetic with scientific notation
(6,250,000,000,000,000,000 electrons per second) x (25 seconds) =
A lemon battery is a battery used in experiments proposed in many science textbooks around the world. It is made by inserting two different metallic objects, for example a galvanized nail and a copper coin, into an ion bridge (for example a lemon, a potato or paper soaked in salt water or acid).
The copper coin serves as the positive electrode or cathode and the galvanized nail as the
Seeking life: The rover is equipped with a drill to gather samples
underground and send them to a self-contained lab to determine if there
are any microorganisms present on the planet.
A rover (or sometimes planetary rover) is a space exploration vehicle designed to move across the surface of a planet or other astronomical body. Some rovers have been designed to transport members of
Sunday, August 5, 2012
A register is a semiconductor device that is used for storing several bits of digital data. It basically consists of a set of flip-flops, with each flip-flop representing one bit of the register.
Thus, an n-bit register has n flip-flops.
A basic register is also known as a 'latch.'
A special type of register, known as the shift register, is used to pass or transfer bits of data from
The Global Positioning System (GPS) is a location system based on a constellation of about 24 satellites orbiting the earth at altitudes of approximately 11,000 miles.
GPS was developed by the United States Department of Defense (DOD), for its tremendous application as a military locating utility.
The DOD's investment in GPS is immense. Billions and billions of dollars have
Saturday, August 4, 2012
What is Rectangular Waveguide?
Rectangular waveguides are the one of the earliest type of the transmission lines. They are used in many applications. A lot of components such as isolators, detectors, attenuators, couplers and slotted lines are available for various standard waveguide bands between 1 GHz to above 220 GHz.
A rectangular waveguide supports TM and TE modes but not
What is Waveguide?
A waveguide is a structure which guides waves, such as electromagnetic waves or sound waves. There are different types of waveguides for each type of wave. The original and most common meaning is a hollow conductive metal pipe used to carry high frequency radio waves, particularly microwaves.
Modes of Operation:
When an electromagnetic wave propagates down
SCRs and GTOs share the same equivalent schematics (two transistors connected in a positive-feedback fashion), the only differences being details of construction designed to grant the NPN transistor a greater β than the PNP. This allows a smaller gate current (forward or reverse) to exert a greater degree of control over conduction from cathode to anode, with the PNP transistor's latched
Google's search engine is a powerful tool. Without search engines like Google, it would be practically impossible to find the information you need when you browse the Web.
Like all search engines, Google uses a special algorithm to generate search results. While Google shares general facts about its algorithm, the specifics are a company secret.
This helps Google remain competitive with
A solar cell is also called as photovoltaic cell is an electrical device that converts the energy of light directly into electricity by the photovoltaic effect. It is a form of photoelectric cell when exposed to light, can generate and support an electric current without being attached to any external voltage source.
Basic structure of silicon based solar cell
Photovoltaics is the field
Diode Vs Resistors
If Resistors are the most basic passive component in electrical or electronic circuits, then we have to consider the Signal Diode as being the most basic "Active" component.
However, unlike a resistor, a diode does not behave linearly with respect to the applied voltage as it has an exponential I-V relationship and therefore can not be described simply by using Ohm's law as
The term high-κ dielectric refers to a material with a high dielectric constant κ (as compared to silicon dioxide) used in semiconductor manufacturing processes which replaces the silicon dioxide gate dielectric. The implementation of high-κ gate dielectrics is to allow further miniaturization of microelectronic components, colloquially referred to as extending Moore's Law.
Two lamps A and B are rated 60W 220V and 100W 220V respectively
Two Bulbs in Series
Lamp A by itself has power of P = I x V ; 60=I x 220 ; so I = 60/220 = 0.27 amperes.
Thus the lamp has a resistance V = I x R ; R=220/0.27 = 807 ohms.
Lamp B by itself has a power of P = I x V ; so I = 100/220 = 0.45 amperes.
Thus the lamp has a resistance V=I x R ; R=220/0.45 = 489
The total power of the system increases if we increase the number of phases.
Two phase system has 40% power more than single phase system.
Three phase system has 50% power more than two phase system.
But in four phase system it is 7% power only.
Also the design of the system will be more complicated. So we have three phase system only
Friday, August 3, 2012
A silicon-controlled rectifier (or semiconductor-controlled rectifier) is a four-layer solid state current controlling device. The name "silicon controlled rectifier" or SCR is General Electric's trade name for a type of thyristor.
This device is generally used in switching applications. In the normal "off" state, the device restricts current to the leakage current.
In class C operation, collector current flows for less than one half cycle of the input signal.
The class C operation is achieved by reverse biasing the emitter-base junction,which sets the dc operating point below cutoff and allows only the portion of the input signal thatovercomes the reverse bias to cause collector current flow. if an input signal amplitude is increased to the point
Unlike Combinational Logic
circuits that change state depending upon the actual signals being applied to their inputs at that time, Sequential Logic
circuits have some form of inherent "Memory" built in to them as they are able to take into account their previous input
state as well as those actually present, a sort of "before" and "after" is involved with sequential circuits.
Power Amplifier Classes
Less than 90o
180 to 360o
Position ofthe Q-point
Centre Point ofthe Load Line
Exactly on theX-axis
In between theX-axis and theCentre Load Line
Poor, 25 to 30%
Better, 70 to 80%
Higher than 80%
Better than Abut less than B50 to 70%
The Class AB Amplifier is a
compromise between the Class A and the Class B configurations above. While
Class AB operation still uses two complementary transistors in its output stage
a very small biasing voltage is applied to the Base of the transistor to bias
it close to the Cut-off region when no input signal is present.
An input signal will cause the
transistor to operate as normal in its