Saturday, August 6, 2011

Hello engineers, Check out our updates

0 comments

Hello engineers, Check out our updates


Google is more secure now: Two step authentication process.

Posted: 06 Aug 2011 07:09 AM PDT


Google said Thursday that it has rolled out its two-step authentication sign-in system to 40 languages across over 150 countries. The service, which is intended to make it more difficult for hackers to break into Google accounts, has been available since February as an optional service but only in English. The two-step verification system combines password-based authentication with a...

[[ This is a content summary only. Visit my website for full links, other content, and more! ]]

5 surprising uses for carbon nanotubes

Posted: 06 Aug 2011 06:36 AM PDT


First discovered under an electron microscope over a half a century ago, carbon nanotubes are one of the most sought-after materials today. The tiny structures are used in dozens of applications that touch nearly every industry, including aerospace, electronics, medicine, defense, automotive, energy, construction, and even fashion. Carbon nanotubes (aka CNTs) are made from graphene sheets...

[[ This is a content summary only. Visit my website for full links, other content, and more! ]]

Thursday, August 4, 2011

www.circuitstoday.com

0 comments

www.circuitstoday.com


TDA2822 amplifier circuit

Posted: 04 Aug 2011 06:10 AM PDT

TDA2822 amplifier circuit ( BTL & Stereo ). TDA2822 is a monolithic integrated audio amplifier circuit that can be configured in stereo mode or bridge mode (BTL). The IC has low crossover distortion, low quiescent current and is available in 16 pin power DIP package. The TDA2822 can be operated from a supply voltage range of 3V to 15V. The main applications of TDA2822 are headphone amplifier, portable audio systems, mini radio, hearing aid, preamplifier etc. The IC can deliver an output power of 0.65W per channel into a 4 ohm loud speaker @ 6V supply voltage in the stereo mode and 1.35W into a 4 ohm loud speaker @ 6V supply voltage in the bridge mode. Circuit diagram. Circuit description. TDA2822 stereo amplifier circuit. TDA2822 IC configured in stereo mode is shown in fig1. The left channel input is applied to the non inverting input (pin1) of the first built in amplifier stage and the right channel input is applied to the non inverting input (pin 16) of the second built in amplifier. The inverting input of these built in amplifiers are connected to ground using separate 1000uF capacitors (C5 and C6). The amplified outputs (left and right) are...

Wednesday, August 3, 2011

www.circuitstoday.com

0 comments

www.circuitstoday.com


PWM inverter circuit

Posted: 03 Aug 2011 07:17 AM PDT

250W PWM inverter circuit SG3524. A 250W PWM inverter circuit built around IC SG3524 is shown here. SG3524 is an integrated switching regulator circuit that has all essential circuitry required for making a switching regulator in single ended or push-pull mode. The built in circuitries inside the SG3524 include pulse width modulator, oscillator, voltage reference, error amplifier, overload protection circuit, output drivers etc. SG3524 forms the heart of this PWM inverter circuit which can correct its output voltage against the variations in the output load. In a non PWM inverter the change in output load directly affects the output voltage (when output load increases output voltage decreases and vice versa), but in a PWM inverter the output voltage remains constant over a range of output load. Circuit diagram of 250W PWM inverter. About the circuit. Resistor R2 and capacitor C1 sets the frequency of the ICs internal oscillator. Preset R1 can be used for fine tuning of the oscillator frequency. Pin 14 and pin 11 are the emitter terminals of the internal driver transistor of the IC. The collector terminals of the driver transistors (pin 13 and 12) are tied together and connected to the +8V rail (output of the...

Final Year Projects | IEEE Projects | Application Projects

0 comments

Final Year Projects | IEEE Projects | Application Projects


Publishing Search Logs – A Comparative Study of Privacy Guarantees

Posted: 03 Aug 2011 03:24 AM PDT

Search engine companies collect the “database of intentions,” the histories of their users’ search queries. These search logs are a gold mine for researchers. Search engine companies, however, are wary of publishing search logs in order not to disclose sensitive information. In this paper we analyze algorithms for publishing frequent keywords, queries and clicks of a search log. We first show how methods that achieve variants of k-anonymity are vulnerable to active attacks. We then demonstrate that the stronger guarantee ensured by epsilon-differential privacy unfortunately does not provide any utility for this problem. We then propose a novel algorithm ZEALOUS and show how to set its parameters to achieve (epsilon, delta)-probabilistic privacy. We also contrast our analysis of ZEALOUS with an analysis by Korolova et al. that achieves (epsilon’, delta’)-indistinguishability. Our paper concludes with a large experimental study using real applications where we compare ZEALOUS and previous work that achieves k-anonymity in search log publishing. Our results show that ZEALOUS yields comparable utility to k-anonymity while at the same time achieving much stronger privacy guarantees.


Engineering Projects

0 comments

Engineering Projects


History and Scope of RFID

Posted: 03 Aug 2011 12:14 AM PDT


History and Scope of RFID

Radio-frequency identification (RFID) is a technology that uses communication through the use of radio waves to exchange data between a reader and an electronic tag attached to an object, for the purpose of identification and tracking.
HISTORY:
In 1945 Leon Theremin invented an espionage tool for the Soviet Union which retransmitted incident radio waves with audio information. Sound waves vibrated a diaphragm which slightly altered the shape of the resonator, which modulated the reflected radio frequency. Even though this device was a covert listening device, not an identification tag, it is considered to be a predecessor of RFID technology, because it was likewise passive, being energized and activated by waves from an outside source.
Similar technology, such as the IFFtransponder developed in the United Kingdom, was routinely used by the allies in World War II to identify aircraft as friend or foe. Transponders are still used by most powered aircraft to this day. Another early work exploring RFID is the landmark 1948 paper by Harry Stockman, titled "Communication by Means of Reflected Power" . Stockman predicted that "... considerable research and development work has to be done before the remaining basic problems in reflected-power communication are solved, and before the field of useful applications is explored."
Mario Cardullo's device in 1973 was the first true ancestor of modern RFID, as it was a passive radio transponder with memory. The initial device was passive, powered by the interrogating signal, and was demonstrated in 1971 to the New York Port Authority and other potential users and consisted of a transponder with 16 bit memory for use as a toll device. The basic Cardullo patent covers the use of RF, sound and light as transmission media. The original business plan presented to investors in 1969 showed uses in transportation (automotive vehicle identification, automatic toll system, electronic license plate, electronic manifest, vehicle routing, vehicle performance monitoring), banking (electronic check book, electronic credit card), security (personnel identification, automatic gates, surveillance) and medical (identification, patient history).
An early demonstration of reflected power (modulated backscatter) RFID tags, both passive and semi-passive, was performed by Steven Depp, Alfred Koelle, and Robert Freyman at the Los Alamos National Laboratory in 1973.The portable system operated at 915 MHz and used 12-bit tags. This technique is used by the majority of today's UHFID and microwave RFID tags.
The first patent to be associated with the abbreviation RFID was granted to Charles Walton in 1983.
The largest deployment of active RFID is the US Department of Defense use of Savi active tags on every one of its more than a million shipping containers that travel outside of the continental United States. The largest passive RFID deployment is the enterprise-wide deployment performed by Wal*Mart which instrumented over 2800 retail stores with over 25,000 reader systems, however the exact number is considered 'corporate confidential'.

2.1.1 DEVELOPMENT:
RFIDs are easy to conceal or incorporate in other items. For example, in 2009 researchers at Bristol University successfully glued RFID micro-transponders to live ants in order to study their behaviour. This trend towards increasingly miniaturized RFIDs is likely to continue as technology advances.
Hitachi holds the record for the smallest RFID chip, at 0.05mm x 0.05mm. This is 1/64th the size of the previous record holder, the mu-chip. Manufacture is enabled by using the silicon-on-insulator (SOI) process. These dust-sized chips can store 38-digit numbers using 128-bit Read Only Memory (ROM). A major challenge is the attachment of the antennas, thus limiting read range to only millimetres.
Potential alternatives to the radio frequencies (0.125–0.1342, 0.140–0.1485, 13.56, and 840–960 MHz) used are seen in optical RFID (or OPID) at 333 THz (900 nm), 380 THz (788 nm), 750 THz (400 nm). The awkward antennas of RFID can be replaced with photovoltaic components and IR-LEDs on the ICs.

 SCOPE OF RFID:
RFID has many applications; for example, it is used in enterprise supply chain management to improve the efficiency of inventory tracking and management. The Healthcare industry has used RFID to create tremendous productivity increases by eliminating "parasitic" roles that don't add value to an organization such as counting, looking for things, or auditing items. Many financial institutions use RFID to track key assets and automate Sarbanes Oxley SOX compliance. Also with recent advances in social media RFID is being used to tie the physical world with the virtual world. RFID in Social Media first came to light in 2010 with facebook's annual conference.
Barcode systems though used for product information, inventory control, etc have some drawbacks as compared to RFID. The amount of information stored in a barcode is very less as compared to RFID. RFID can store up to 1000 bytes of data. An RFID is specific to each item, whereas the barcode is not. Barcode needs human interaction for proper operation. It requires time-of-sight access to an optical scanner for the product related information. The barcode is to be replaced if the information it contains needs modification, but in RFID it can be modified at stages of the supply chain by the interaction between the microchip and the reader software. The barcode system is less accurate as compared to RFID.
 Working of  RFID click here

Tuesday, August 2, 2011

Hello engineers, Check out our updates

0 comments

Hello engineers, Check out our updates


Paper presentations: Power optimization

Posted: 02 Aug 2011 03:43 AM PDT

Hello engineers, Todays latest paper presentations for electrical engineers! An RF transceiver includes a low noise amplifier module, a blocking circuit, a down-conversion module, a processing module, an up-conversion module, and a power amplifier module. The low noise amplifier module amplifies inbound RF signals. The blocking circuit, when enabled, substantially attenuates a blocking...

[[ This is a content summary only. Visit my website for full links, other content, and more! ]]


Antenna designing projects materials. (Rare collection)

Posted: 02 Aug 2011 12:03 AM PDT

This is an post for projects on antenna designing for the local area networks (Wi-Fi). These antennas are important for improving various parameters like coverage area, signal strength, focusing. These are really good collections of papers for any engineering project.  Sample topics covered: RF Basics Frequency, bands and bandwidth ,Wavelength ,Amplitude and power...

[[ This is a content summary only. Visit my website for full links, other content, and more! ]]


www.circuitstoday.com

0 comments

www.circuitstoday.com


100W MOSFET power amplifier

Posted: 02 Aug 2011 04:16 AM PDT

100W MOSFET power amplifier. A 100W MOSFET power amplifier circuit based on IRFP240 and IRFP9240 MOSFETs is shown here. The amplifier operates from a +45/-45 V DC dual supply and can deliver 100 watt rms into an 8 ohm speaker and 160 watt rms into a 4 ohm speaker. This Hi-Fi amplifier circuit is suitable for a lot applications like general purpose amplifier, guitar amplifier, keyboard amplifier. The amplifier can be also used as a sub woofer amplifier but a subwoofer filter stage has to be added before the input stage. The amplifier has a low distortion of 0.1%, a damping factor greater than 200, input sensitivity of 1.2V and the bandwidth is from 4Hz to 4 KHz. Circuit diagram. About the circuit. Capacitor C8 is the input DC decoupling capacitor which blocks DC voltage if any from the input source. IF unblocked, this DC voltage will alter the bias setting s of the succeeding stages. Resistor R20 limits the input current to Q1 C7 bypasses any high frequency noise from the input. Transistor Q1 and Q2 forms the input differential pair and the constant current source circuit built around Q9 and Q10 sources 1mA. Preset R1 is used for...

Hello engineers, Check out our updates

Saturday, August 6, 2011

Hello engineers, Check out our updates


Google is more secure now: Two step authentication process.

Posted: 06 Aug 2011 07:09 AM PDT


Google said Thursday that it has rolled out its two-step authentication sign-in system to 40 languages across over 150 countries. The service, which is intended to make it more difficult for hackers to break into Google accounts, has been available since February as an optional service but only in English. The two-step verification system combines password-based authentication with a...

[[ This is a content summary only. Visit my website for full links, other content, and more! ]]

5 surprising uses for carbon nanotubes

Posted: 06 Aug 2011 06:36 AM PDT


First discovered under an electron microscope over a half a century ago, carbon nanotubes are one of the most sought-after materials today. The tiny structures are used in dozens of applications that touch nearly every industry, including aerospace, electronics, medicine, defense, automotive, energy, construction, and even fashion. Carbon nanotubes (aka CNTs) are made from graphene sheets...

[[ This is a content summary only. Visit my website for full links, other content, and more! ]]

www.circuitstoday.com

Thursday, August 4, 2011

www.circuitstoday.com


TDA2822 amplifier circuit

Posted: 04 Aug 2011 06:10 AM PDT

TDA2822 amplifier circuit ( BTL & Stereo ). TDA2822 is a monolithic integrated audio amplifier circuit that can be configured in stereo mode or bridge mode (BTL). The IC has low crossover distortion, low quiescent current and is available in 16 pin power DIP package. The TDA2822 can be operated from a supply voltage range of 3V to 15V. The main applications of TDA2822 are headphone amplifier, portable audio systems, mini radio, hearing aid, preamplifier etc. The IC can deliver an output power of 0.65W per channel into a 4 ohm loud speaker @ 6V supply voltage in the stereo mode and 1.35W into a 4 ohm loud speaker @ 6V supply voltage in the bridge mode. Circuit diagram. Circuit description. TDA2822 stereo amplifier circuit. TDA2822 IC configured in stereo mode is shown in fig1. The left channel input is applied to the non inverting input (pin1) of the first built in amplifier stage and the right channel input is applied to the non inverting input (pin 16) of the second built in amplifier. The inverting input of these built in amplifiers are connected to ground using separate 1000uF capacitors (C5 and C6). The amplified outputs (left and right) are...

www.circuitstoday.com

Wednesday, August 3, 2011

www.circuitstoday.com


PWM inverter circuit

Posted: 03 Aug 2011 07:17 AM PDT

250W PWM inverter circuit SG3524. A 250W PWM inverter circuit built around IC SG3524 is shown here. SG3524 is an integrated switching regulator circuit that has all essential circuitry required for making a switching regulator in single ended or push-pull mode. The built in circuitries inside the SG3524 include pulse width modulator, oscillator, voltage reference, error amplifier, overload protection circuit, output drivers etc. SG3524 forms the heart of this PWM inverter circuit which can correct its output voltage against the variations in the output load. In a non PWM inverter the change in output load directly affects the output voltage (when output load increases output voltage decreases and vice versa), but in a PWM inverter the output voltage remains constant over a range of output load. Circuit diagram of 250W PWM inverter. About the circuit. Resistor R2 and capacitor C1 sets the frequency of the ICs internal oscillator. Preset R1 can be used for fine tuning of the oscillator frequency. Pin 14 and pin 11 are the emitter terminals of the internal driver transistor of the IC. The collector terminals of the driver transistors (pin 13 and 12) are tied together and connected to the +8V rail (output of the...

Final Year Projects | IEEE Projects | Application Projects

Final Year Projects | IEEE Projects | Application Projects


Publishing Search Logs – A Comparative Study of Privacy Guarantees

Posted: 03 Aug 2011 03:24 AM PDT

Search engine companies collect the “database of intentions,” the histories of their users’ search queries. These search logs are a gold mine for researchers. Search engine companies, however, are wary of publishing search logs in order not to disclose sensitive information. In this paper we analyze algorithms for publishing frequent keywords, queries and clicks of a search log. We first show how methods that achieve variants of k-anonymity are vulnerable to active attacks. We then demonstrate that the stronger guarantee ensured by epsilon-differential privacy unfortunately does not provide any utility for this problem. We then propose a novel algorithm ZEALOUS and show how to set its parameters to achieve (epsilon, delta)-probabilistic privacy. We also contrast our analysis of ZEALOUS with an analysis by Korolova et al. that achieves (epsilon’, delta’)-indistinguishability. Our paper concludes with a large experimental study using real applications where we compare ZEALOUS and previous work that achieves k-anonymity in search log publishing. Our results show that ZEALOUS yields comparable utility to k-anonymity while at the same time achieving much stronger privacy guarantees.


Engineering Projects

Engineering Projects


History and Scope of RFID

Posted: 03 Aug 2011 12:14 AM PDT


History and Scope of RFID

Radio-frequency identification (RFID) is a technology that uses communication through the use of radio waves to exchange data between a reader and an electronic tag attached to an object, for the purpose of identification and tracking.
HISTORY:
In 1945 Leon Theremin invented an espionage tool for the Soviet Union which retransmitted incident radio waves with audio information. Sound waves vibrated a diaphragm which slightly altered the shape of the resonator, which modulated the reflected radio frequency. Even though this device was a covert listening device, not an identification tag, it is considered to be a predecessor of RFID technology, because it was likewise passive, being energized and activated by waves from an outside source.
Similar technology, such as the IFFtransponder developed in the United Kingdom, was routinely used by the allies in World War II to identify aircraft as friend or foe. Transponders are still used by most powered aircraft to this day. Another early work exploring RFID is the landmark 1948 paper by Harry Stockman, titled "Communication by Means of Reflected Power" . Stockman predicted that "... considerable research and development work has to be done before the remaining basic problems in reflected-power communication are solved, and before the field of useful applications is explored."
Mario Cardullo's device in 1973 was the first true ancestor of modern RFID, as it was a passive radio transponder with memory. The initial device was passive, powered by the interrogating signal, and was demonstrated in 1971 to the New York Port Authority and other potential users and consisted of a transponder with 16 bit memory for use as a toll device. The basic Cardullo patent covers the use of RF, sound and light as transmission media. The original business plan presented to investors in 1969 showed uses in transportation (automotive vehicle identification, automatic toll system, electronic license plate, electronic manifest, vehicle routing, vehicle performance monitoring), banking (electronic check book, electronic credit card), security (personnel identification, automatic gates, surveillance) and medical (identification, patient history).
An early demonstration of reflected power (modulated backscatter) RFID tags, both passive and semi-passive, was performed by Steven Depp, Alfred Koelle, and Robert Freyman at the Los Alamos National Laboratory in 1973.The portable system operated at 915 MHz and used 12-bit tags. This technique is used by the majority of today's UHFID and microwave RFID tags.
The first patent to be associated with the abbreviation RFID was granted to Charles Walton in 1983.
The largest deployment of active RFID is the US Department of Defense use of Savi active tags on every one of its more than a million shipping containers that travel outside of the continental United States. The largest passive RFID deployment is the enterprise-wide deployment performed by Wal*Mart which instrumented over 2800 retail stores with over 25,000 reader systems, however the exact number is considered 'corporate confidential'.

2.1.1 DEVELOPMENT:
RFIDs are easy to conceal or incorporate in other items. For example, in 2009 researchers at Bristol University successfully glued RFID micro-transponders to live ants in order to study their behaviour. This trend towards increasingly miniaturized RFIDs is likely to continue as technology advances.
Hitachi holds the record for the smallest RFID chip, at 0.05mm x 0.05mm. This is 1/64th the size of the previous record holder, the mu-chip. Manufacture is enabled by using the silicon-on-insulator (SOI) process. These dust-sized chips can store 38-digit numbers using 128-bit Read Only Memory (ROM). A major challenge is the attachment of the antennas, thus limiting read range to only millimetres.
Potential alternatives to the radio frequencies (0.125–0.1342, 0.140–0.1485, 13.56, and 840–960 MHz) used are seen in optical RFID (or OPID) at 333 THz (900 nm), 380 THz (788 nm), 750 THz (400 nm). The awkward antennas of RFID can be replaced with photovoltaic components and IR-LEDs on the ICs.

 SCOPE OF RFID:
RFID has many applications; for example, it is used in enterprise supply chain management to improve the efficiency of inventory tracking and management. The Healthcare industry has used RFID to create tremendous productivity increases by eliminating "parasitic" roles that don't add value to an organization such as counting, looking for things, or auditing items. Many financial institutions use RFID to track key assets and automate Sarbanes Oxley SOX compliance. Also with recent advances in social media RFID is being used to tie the physical world with the virtual world. RFID in Social Media first came to light in 2010 with facebook's annual conference.
Barcode systems though used for product information, inventory control, etc have some drawbacks as compared to RFID. The amount of information stored in a barcode is very less as compared to RFID. RFID can store up to 1000 bytes of data. An RFID is specific to each item, whereas the barcode is not. Barcode needs human interaction for proper operation. It requires time-of-sight access to an optical scanner for the product related information. The barcode is to be replaced if the information it contains needs modification, but in RFID it can be modified at stages of the supply chain by the interaction between the microchip and the reader software. The barcode system is less accurate as compared to RFID.
 Working of  RFID click here

Hello engineers, Check out our updates

Tuesday, August 2, 2011

Hello engineers, Check out our updates


Paper presentations: Power optimization

Posted: 02 Aug 2011 03:43 AM PDT

Hello engineers, Todays latest paper presentations for electrical engineers! An RF transceiver includes a low noise amplifier module, a blocking circuit, a down-conversion module, a processing module, an up-conversion module, and a power amplifier module. The low noise amplifier module amplifies inbound RF signals. The blocking circuit, when enabled, substantially attenuates a blocking...

[[ This is a content summary only. Visit my website for full links, other content, and more! ]]


Antenna designing projects materials. (Rare collection)

Posted: 02 Aug 2011 12:03 AM PDT

This is an post for projects on antenna designing for the local area networks (Wi-Fi). These antennas are important for improving various parameters like coverage area, signal strength, focusing. These are really good collections of papers for any engineering project.  Sample topics covered: RF Basics Frequency, bands and bandwidth ,Wavelength ,Amplitude and power...

[[ This is a content summary only. Visit my website for full links, other content, and more! ]]


www.circuitstoday.com

www.circuitstoday.com


100W MOSFET power amplifier

Posted: 02 Aug 2011 04:16 AM PDT

100W MOSFET power amplifier. A 100W MOSFET power amplifier circuit based on IRFP240 and IRFP9240 MOSFETs is shown here. The amplifier operates from a +45/-45 V DC dual supply and can deliver 100 watt rms into an 8 ohm speaker and 160 watt rms into a 4 ohm speaker. This Hi-Fi amplifier circuit is suitable for a lot applications like general purpose amplifier, guitar amplifier, keyboard amplifier. The amplifier can be also used as a sub woofer amplifier but a subwoofer filter stage has to be added before the input stage. The amplifier has a low distortion of 0.1%, a damping factor greater than 200, input sensitivity of 1.2V and the bandwidth is from 4Hz to 4 KHz. Circuit diagram. About the circuit. Capacitor C8 is the input DC decoupling capacitor which blocks DC voltage if any from the input source. IF unblocked, this DC voltage will alter the bias setting s of the succeeding stages. Resistor R20 limits the input current to Q1 C7 bypasses any high frequency noise from the input. Transistor Q1 and Q2 forms the input differential pair and the constant current source circuit built around Q9 and Q10 sources 1mA. Preset R1 is used for...
 

Copyright 2008 All Rights Reserved | Blogger Template by Bloganol and Smart Blogging Tips | Distributed by Deluxe Templates