Showing posts with label technologies. Show all posts
kinect technology
have a look over inner hardware.
a small video explains how actually a kniect technology works..
- hardware
- software
have a look over inner hardware.
a small video explains how actually a kniect technology works..
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
Carrier signal sent out through the antennas
Carrier signal hits tag(s)
step2:- Tag receives and modifies carrier signal
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!!!
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
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:-
