Showing posts with label technologies. Show all posts
what is RFID?
Radio Frequency Identification CardRadio-frequency identification (RFID) is the wireless non-contact use of radio-frequency electromagnetic fields to transfer data, for the purposes of automatically identifying and tracking tags attached to object
- rfid tags serves purpose like Bar code and Magnetic strip on the back of credit card or ATM cards
Simple Understanding of RFID Technology .
The tag gets power from the rfid reader and data from rfid tag will reaches rfid tag by radio frequency
waves
waves
communication between rfid tag and rfid reader
Reader and tag communicate via RF signal
step1:- Carrier signal generated by the reader
Carrier signal sent out through the antennas
Carrier signal hits tag(s)
step2:- Tag receives and modifies carrier signal
– “sends back” modulated signal (Passive Backscatter – also referred to
as “field disturbance device”)
Antennas receive the modulated signal and send them to the Reader
step3:- Reader decodes the data
Results returned to the host application
RFID components:
it has two parts rfid tag and rfid reader.- components in rfid tag
antenna
ic or microcontroller to store the data
- components of rfid reader
same as rfid tag including the processor with software to decode the
information stored in ic of rfid tag and stores this information in the database of the computer
Types of RFID.
- Passive vs. Active RFID Comparison
The primary difference between passive and active RFID tags is that active tags are powered by a battery and automatically broadcast their signal, whereas passive tags do not have a power source and only transmit a signal upon receiving RF energy emitted from a reader in proximity of the tag.
Passive Active Read Range Up to 40 feet (fixed readers)
Up to 20 feet (handheld readers)Up to 300 feet or more Power No power source Battery powered Tag Life Up to 10 years depending upon the environment the tag is in 3-8 years depending upon the tag broadcast rate Tag Costs $.10-4.00 or more depending upon quantity, durability, and form-factor $15-50 depending upon quantity, options (motion sensor, tamper detection, temperature sensor), and form-factor Ideal Use For inventorying assets using handheld RFID readers (daily, weekly, monthly quarterly, annually). Can also be used with fixed RFID readers to track the movement of assets as long as security is not a requirement. For use with fixed RFID readers to perform real-time asset monitoring at choke-points or within zones. Can provide a better layer of security than passive RFID. Readers Typically higher cost Typically lower cost
they were many types of rfid tags based on memory storage:-
- read only
• Can never be changed
• No additional data can be assigned to the tag
2.write once ready many
Tag is locked once written(like dvd)
3.read/write
Tag data can be change over time(data can be editable)
based on the purpose we will choose the tags that serves the purpose
RFID vs Bar Code?
No line of sight required for reading
Multiple items can be read with a single scan
Each tag can carry a lot of data (read/write)
Individual items identified and not just the category
Passive tags have a virtually unlimited lifetime
Active tags can be read from great distances
Can be combined with barcode technology
Applications of RFID:-
wall mart is first to use rfid technology, it enable to improve it's efficiency of global supplying and accurate ordering delivery
it played a remarkable role in manufacturing retails, defense,travelling any many more sectors
the following are important applications:-
will be updated soon!!!!
how to make our own rfid tag and reader?
will be updated soon!!!
wireless charging technology
Sunday, 17 March 2013
Posted by AVINASH CHAKRAVARTHI
Tag :
projects,
technologies
Its no more science fiction...it came into exist...we need to know how it rules our future & how it works????
million of answers available in internet for the question " how it works?"..
thousands of videos on YouTube demonstrates the wireless charging..
yet.....there is a question" how it actually works ?"
here we go...i will promise u ." u will learn at least 5 % on how it works and u will make u r own wireless charger for u r gadgets .."
1.what is wireless charging?
2. how it works?
Wireless charging, also known as inductive charging, is based on a few
simple principles. The technology requires two coils: a transmitter and a
receiver. An alternating current is passed through the transmitter
coil, generating a magnetic field. This in turn induces a voltage in the
receiver coil; this can be used to power a mobile device or charge a
battery.
- explanation with block diagram
both transmitter (TX) and receiver (Rx) coils are made up of copper coil.
rectifier is used to convert the ac signal to dc signals.
3. basic principle and it's efficiency factors:-
As i already told u ,the principle is mutual induction between the TX and receiver coil
let the induction of TX coil is L1 ,
inductance of RX coil is Rx,
distance between the coils are Z,
diameter of TX and RX coil be D1 and D2.
- the efficiency of the wireless power transmission depends on the 1, coupling factor
2, quality factor
A. COUPLING FACTOR:-
The coupling is determined by the distance between the inductors (z) and the relative size (D2 /D1). The coupling is further determined by the shape of the coils and the angle between them
- The efficiency drops dramatically at larger distance (z/D > 1) or at a large size difference of the coil (D2/D1 < 0.3)
- A high efficiency (>90%) can be achieved at close distance (z/D < 0.1) and for coils of similar size (D2/D = 0.5..1)
B. QUALITY FACTOR:-
The ratio of the inductance L to the resistance R of a coil remains constant for different winding arrangements in the same volume and shape. It makes sense to define this value as a figure of merit to distinguish different coil structures. The quality factor Q is defined by this ratio.The voltage, which is induced by the same current in an inductor scales with the frequency f and thus the apparent power in the device.
The general definition of the quality factor is based on the ratio of apparent power to the power losses in a device
Remember quality factor is not under our control it is designed by the manufacturer
the value of quality factor will be 0 to infinity,For mass production you may expect values around 100
The power losses while transmission can be expressed as loss factor

which is the sum of all losses related to the transferred power. A deeper analysis results in an minimum loss factor, which can be achieved by a given wireless power system, if it is proper matched to load and generator:

Which can be reduced to:

The equation is only dependent on the two basic parameters of the wireless power system: The coupling factor k between the receiver and transmitter coil and the system quality factor Q. The system quality factor is the geometrical average of the transmitter’s and receiver’s quality factors.
BLAH BLAH BLAH......... there is no end to learning , it goes on...so stop it ..just apply the knowledge what u have learned so far....
6.how wireless better than wired????
4. calculation for getting max efficiency:-
The power losses while transmission can be expressed as loss factor
which is the sum of all losses related to the transferred power. A deeper analysis results in an minimum loss factor, which can be achieved by a given wireless power system, if it is proper matched to load and generator:
Which can be reduced to:
The equation is only dependent on the two basic parameters of the wireless power system: The coupling factor k between the receiver and transmitter coil and the system quality factor Q. The system quality factor is the geometrical average of the transmitter’s and receiver’s quality factors.
- This means, that the system quality factor and the coupling factor determine the performance in an equivalent way. A worse coupling can be linearly compensated by a better quality factor and vice versa.
BLAH BLAH BLAH......... there is no end to learning , it goes on...so stop it ..just apply the knowledge what u have learned so far....
5.circuit diagram:-
in the first section, ac 220v and 50 Hz is converted in to 12v and 40 kHz .u can also use frequency generator (usually available in all electrical labs) to achieve this purpose.
these transmitter coils is resonated with the receiver coil where these ac current is converted into dc current by using bridge rectifiers and filter capacitors , to run the dc load (here i used a dc fan (5v))
6.how wireless better than wired????
please give u r feed back...
Cloud Computing

Nowadays, Cloud Computing is one of the trending technology and it is becoming an essential part for the corporate world. Many companies are shifting from their traditional way to Cloud computing . In this article I will answer some simple questions about Cloud computing i.e. "Why Cloud Computing?", "What is Cloud Computing ?", "How Cloud Computing works ?". In the End is the list of Top 10 service provider of Cloud computing of 2012.
Why Cloud Computing ?
This technology allows business to reduce IT operational costs by simply maintaining software and outsourcing hardware resources.
Cloud is an optimal option when it comes to data sharing, that is why is use in industries is increasing on the fast pace.
1. It bring down the IT operational cost. Reduced cost of work which means GOOD FOR BUSINESS. Hence Cloud computing making its day under the Sun.
2. Cloud computing provides much greater freedom to share and use the data. As data is present over the internet a user can it anytime and anywhere by using any device (like mobile, tablet, computer etc). Since it require basic hardware structure so the cost of hardware is also reduced.
3. As in business Time is Money, using Cloud computing there is not downtime there is only installation of one application for doing all the work. Hence it maintains everyone in organization on the same page and reduce the time to update and installation of different software for different application, hence reduce maintenance price.
4. Security is most concerned issue in industries, which why usage of Cloud computing is increasing at the good rate because it provide more security than scattered network.
5.Ease of Access and Ease of Use, both the things are loved by the industries and clouds provides these in very organized way that why clouds are working.
So many benefits and only few downsides, so Cloud Computing is a good choice for IT operations.
What is Cloud computing ?
According to the name "Cloud computing ", ' Cloud ' specify the representation of the complex network as a Cloud in the system network diagram and ' Computing ' simply suggest that the art of doing some work, mainly with computers.
All work is done by Web based service. Cloud computing run through Interface software. The Third party servers holds all the information software, your saved data and most important security.
How it Works ?
Cloud computing setup can be describes as two ends "Front end" and "Back end". Front end is the user or the IT organization which have the Interface software like custom programs, word processing, etc, and their licenses. Back end is the other end which is cloud provider.It is the network application servers and database storage. These cloud provider have all the hardware having capability of doing any work of any kind of application required by the user.
Concerns of the Cloud computing
1. User does not physically have the data with them, everything on the cloud.
2. Risk of hacking of the Storage.
3. All work become reliable on the Internet speed.
4. More Knowledge is required for implementing and managing clouds.
List of top 10 Cloud computing providers of 2012
10. VMware
9. Microsoft
8. Bluelock
7. Citrix
6. Joyent
5. Terremark/ Verizon
4. Salesforce.com
3. CenturyLink / Savvis
2. Rackspace
1. Amazon web services
Amazon web services is on the Top of the all the service providers this year. It is the dominant public provider of the cloud worldwid













