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Showing posts from 2014

Nano Technology In Electronics

Sun power source

SOLAR ENERGY Introduction:  Sun is the major source of energy that our earth receivesonly 174 petawatts energy of it. The outer core temperature of the sun would be around 5000 degree Celsius whereas our earth receives few percent of it.  It is an important source of  renewable energy  and its technologies are broadly characterized as either  passive solar  or  active solar  depending on the way they capture and distribute solar energy or convert it into  solar power . Active solar techniques include the use of  photo-voltaic systems ,  concentrated solar power  and  solar water heating  to harness the energy. Passive solar techniques include orienting a building to the Sun, selecting materials with favorable  thermal mass  or light dispersing properties, and designing spaces that  naturally circulate air . Basic  definition : Solar energy   is radiant light and heat from the  sun   harnessed using a range of ever-evolving technologies such as   solar heating ,   solar  photov

Full Wave Bridge Rectifier With Capacitor Filter

 Full Wave Bridge Rectifier With Capacitor Filter The voltage obtained across the load resistor of the full-wave bridge rectifier described above has a large amount of ripple. A capacitor filter may be added to smooth-en the ripple in the output, as shown below. Figure 21: Full wave Bridge rectifier with capacitor filter The rectifier circuits discussed above can be used to charge batteries and to convert AC voltages into constant DC voltages. Full-wave and bridge rectifier are more commonly used than half-wave rectifier.

What is an Arduino?

Introduction Arduino  is an open-source platform used for building electronics projects. Arduino consists of both a physical programmable circuit board (often referred to as a  microcontroller ) and a piece of  software , or IDE (Integrated Development Environment) that runs on your computer, used to write and upload computer code to the physical board. The Arduino platform has become quite popular with people just starting out with electronics, and for good reason. Unlike most previous programmable circuit boards, the Arduino does not need a separate piece of hardware (called a programmer) in order to load new code onto the board – you can simply use a USB cable. Additionally, the Arduino IDE uses a simplified version of C++, making it easier to learn to program. Finally, Arduino provides a standard form factor that breaks out the functions of the micro-controller into a more accessible package. This is an Arduino Uno The Uno is one of the more popular boards in the Arduin

AC-Powered Led Lamps Without rectifiers

AC-Powered Led Lamps Without rectifiers Usually, LED lamps require rectifier when connected to the AC mains power supply. Electrical isolation of the LED lamps from the mains is also required in most cases. But rectifiers create a switching noise and also add to their cost. Presented here is a simple circuit for LED lamps that doesn’t require the use of rectifiers. There is a wide range of low-power mains transformers available with one or more secondary voltages like 2.5 Vrms (3.5 Vpeak), 3 Vrms (4.2 Vpeak), 3.3 Vrms (4.7 Vpeak), 4.5 Vrms (6.4 Vpeak), 5 Vrms (7.1 Vpeak), 6 Vrms (8.5 Vpeak), 6.3 Vrms (8.9 Vpeak) and with power rating from 1.3 VA up to 12 VA. The primary current of these transformers is relatively low—around 15 to 80 mA—and, when needed, can be limited with resistors without producing a lot of heat. Most of these transformers are PCB-mounted and easy to use. On the other hand, LED lamps with power rating of 1 W to 10 W are good enough to produce light for your w

MATLAB

Introduction to MATLAB Goal The goal of this tutorial is to give a brief introduction to the mathematical software MATLAB. After completing the worksheet you should know how to start MATLAB, how to use the elementary functions in MATLAB and how to use MATLAB to plot functions. What is MATLAB? MATLAB is widely used in all areas of applied mathematics, in education and research at universities, and in the industry. MATLAB stands for MATrix LABoratory and the software is built up around vectors and matrices. This makes the software particularly useful for linear algebra but MATLAB is also a great tool for solving algebraic and differential equations and for numerical integration. MATLAB has powerful graphic tools and can produce nice pictures in both 2D and 3D. It is also a programming language, and is one of the easiest programming languages for writing mathematical programs. MATLAB also has some tool boxes useful for signal processing, image processing, optimization, etc. How

Fuel cell

Fuel Cell Basics Hydrogen Basics Hydrogen: No.1 on the periodic table Fuel cells run on hydrogen, the simplest element and most plentiful gas in the universe. Hydrogen is a diatomic element, meaning that in its liquid and solid states, hydrogen naturally forms into pairs of atoms, which is why hydrogen is often referred to as “H 2 ”. Hydrogen is the lightest element, yet it has the highest energy content per unit weight of all fuels. Hydrogen’s energy density is 52,000 Btu/lb., which is three times greater than that of gasoline. In nature, hydrogen is never found on its own; it is always combined into molecules with other elements, typically oxygen and carbon. Hydrogen can be extracted from virtually any hydrogen-containing compound, including both renewable and non-renewable resources. Regardless of the fuel source, fuel cells utilize hydrogen with little to no polluting emissions, making hydrogen the ultimate clean energy carrier. Safety Hydrogen gas is similar

Types of Fuel Cells

Fuel cells are a family of technologies that generate electricity through electrochemical processes, rather than combustion. There are many fuel cell types, but the principal ones include the alkaline fuel cell (AFC), proton exchange membrane (PEM) fuel cell, direct methanol fuel cell (DMFC), molten carbonate fuel cell (MCFC), phosphoric acid fuel cell (PAFC), and solid oxide fuel cell (SOFC). A number of these fuel cell types are commercially available today. Each fuel cell type has its own unique chemistry, such as different operating temperatures, catalysts, and electrolytes. A fuel cell’s operating characteristics help define its application – for example, lower temperature PEM and DMFC fuel cells are used to power passenger vehicles and forklifts, while larger, higher temperature MCFC and PAFC fuel cells are used for stationary power generation. Researchers continue to improve fuel cell technologies, examining different catalysts and electrolytes in order to improve per

Wireless Power Transmission

The technology for  wireless power transmission or wireless power transfer  ( WPT ) is in the forefront of electronic development. Applications involving microwaves, solar cells, lasers, and resonance of electromagnetic waves have had the most recent success with WPT.  The main function of wireless power transfer is to allow electrical devices to be continuously charged and lose the constraint of a power cord.  Although the idea is only a theory and not widely implemented yet, extensive research dating back to the 1850’s has led to the conclusion that WPT is possible.  The three main systems used for WPT are microwaves, resonance, and solar cells. Microwaves would be used to send electromagnetic radiation from a power source to a receiver in an electrical device.  The concept of resonance causes electromagnetic radiation at certain frequencies to cause an object to vibrate.  This vibration can allow energy to be transmitted between the two vibrating sources.  Solar cells, ideal

How Does A Solar Tracker Work?

Trackers direct solar panels or modules toward the sun. These devices change their orientation throughout the day to follow the sun’s path to maximize energy capture. In photo voltaic systems, trackers help minimize the angle of incidence (the angle that a ray of light makes with a line perpendicular to the surface) between the incoming light and the panel, which increases the amount of energy the installation produces. Concentrated solar photovoltaics and concentrated solar thermal have optics that directly accept sunlight, so solar trackers must be angled correctly to collect energy. All concentrated solar systems have trackers because the systems do not produce energy unless directed correctly toward the sun. Single-axis solar trackers rotate on one axis moving back and forth in a single direction. Different types of single-axis trackers include horizontal, vertical, tilted, and polar aligned, which rotate as the names imply. Dual-axis trackers continually face the sun becau

Rectifiers

RECTIFIERS  Introduction All electronic circuits need dc power supply from battery or power pack units.It may be economical anc convenient to depend upon battery power supply.hence, many electronic equipment contain circuits which convert ac supply into dc voltage at the required level.The unit containing these circuits is called Linear Mode Power Supply(LMPS). In certain applications, dc to dc conversion is required. Such a power supply unit that converts dc to ac or to dc is called Switch Mode Power Supply. Rectifier It is defined as an electronic device used for converting ac voltage into pulse rating dc voltage.It consist of PN junction diode which is polarity sensitive.when the diode is in forward bias, the diode 'D' conducts and allows the current to flow through it. It without any resistance i.e diode is on state. When the diode is in reverse bias it doesn't conducts then no current flows through it, i.e diode is in 'off' state providing a block

Home Security System

     Home Security System by: Debraj Nath B.Tech (Electrical and Electronics engineering) Introduction Home security system is a combination of following alarm systems a.     Fire Alarm b.     Rain Alarm c.     Foot Step Intruder Alarm d.     Water Level Indicator Alarm e.     Light Alarm The main concept to include all the different types of alarm is to secure the entire home from all types of calamities may be natural or man-made. The circuit could also be helpful to save the intruders like thief attack. a.     The fire alarm is fitted in such place in home where there may be chance of getting fire such as kitchen, near electrical distribution system of house, gas system of house etc. b.     The rain alarm is fitted on the roof of the house so that when a water falls on the roof of the house the circuit gets its conducting situation and the alarm would start its operation so that the people inside the house will get notified about the weather con