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Showing posts from May, 2013

Delay using 8051 timer.

The 8051 microcontroller has two independent 16 bit up counting timers named Timer 0 and Timer 1 and this article is about generating time delays using the 8051 timers. Generating delay using pure software loops have been already discussed here but such delays are poor in accuracy and cannot be used in sensitive applications. Delay using timer is the most accurate and surely the best method. A timer can be generalized as a multi-bit counter which increments/decrements itself on receiving a clock signal and produces an interrupt signal up on roll over. When the counter is running on the processor’s clock , it is called a “Timer”, which counts a predefined number of processor clock pulses and  generates a programmable delay. When the counter is running on an external clock source (may be a periodic or aperiodic external signal) it is called a “Counter” itself and it can be used for counting external events. In  8051, the oscillator output is divided by 12 using a divide…

MAKE 12V TO 240 V

RF Based Wireless Remote Control System

It is often required to switch electrical appliances from a distance without being a direct line of sight between the transmitter and receiver. As you may well know, an RF based wireless remote control system (RF Transmitter & RF Receiver) can be used to control an output load from a remote place. RF transmitter , as the name suggests, uses radio frequency to send the signals at a particular frequency and a baud rate.
The RF receiver can receive these signals only if it is configured for the pre-defined signal/data pattern. An ideal solution for this application is provided by compact transmitter and receiver modules, which operate at a frequency of 434 MHz and are available ready-made. Here, the radio frequency (RF) transmission system employs Amplitude Shift Keying (ASK) with transmitter (and receiver) operating at 434 MHz. The use of the ready-made RF module simplifies the construction of a wireless remote control system and also makes it more reliable.
RF…

India’s Second Solar Powered Train

In India there are 2 solar powered trains that were transformed from normal passenger trains into ones equipped with solar panels. Also they replaced the normal light bulbs with LEDs which has an illumination level of 42 lux compared to previously illumination level which was 20 lux, when it was a normal train.

The train has been installed with solar-powered sockets, which will enable recharging of mobiles and cameras during their journey. The overall cost of converting the train into a solar power unit was around Rs 225,000, that is equal to $4500.

The Graphene Supercapacitor Revolution!

You wouldn’t believe what they have discovered while making some experiments with the graphene – a Nobel-prize winning supermaterial. They were trying to produce high-quality sheets of graphene using a regular DVD-Burner and they succeeded, but the real surprise came when a researcher in Richard Kaner‘s lab wired a small square of their high quality carbon sheets up to a LED and it lit!

The graphene “supercapacitor” was charged only for 3 seconds but the LED run for over 5 minutes! I think this is very important and the world will soon change and the well-known batteries will soon be changed for good with these type of graphene supercapacitors which have a high energy storage and charges and discharges 1200 times faster than a battery.
Imagine the future where we will charge our devices in seconds, where electric cars will be everywhere and you can charge their batteries in minutes, even faster! Not to mention that the graphene supercapacitor is ecological.

infrared-transmitter-

This infrared transmitter use PWM (pulse width modulation).
The transmitter is equiped with LM567, tone decoder circuit. Audio signal ( at least 50mVvv ) is amplified with T1 and then it is used to modulate IC1. Infrared transmitter frequency is adjusted with P2 between 25 and 40KHz.

LM567, NE567, SE567 Datasheet

The LM567, NE567 and SE567 are general purpose tone decoders designed to provide a saturated transistor switch to ground when an input signal is present within the passband. The circuit consists of an I and Q detector driven by a voltage controlled oscillator which determines the center frequency of the decoder. External components are used to independently set center frequency, bandwidth and output delay.
567 Applications
Touch Tone DecodingPrecision OscillatorFrequency Monitoring and ControlWide Band FSK DemodulationUltrasonic ControlsCarrier Current Remote ControlsCommunications Paging Decoders

Low Voltage Audio Amplifier

This experimental (3) transistor class A audio power amplifier delivers 25mW into an 8Ω load, or 50mW into a 4Ω load using only a 1.5V power source. At such low voltages, there are many issues to consider and much to learn. To the best of my knowledge the following information is new to the world.
Theoretical minimum vs. practical minimum voltage

Hearing Aids Circuit

The medium-power amplifier section is wired around popular audio amplifier IC TDA2822M (not TDA2822). This IC, specially designed for portable low-power applications, is readily available in 8-pin mini DIP package. Here the IC is wired in bridge configuration to drive the 32-ohm general-purpose monophonic earphone.
The audio output of this hearing aid circuit is 10 to 15 mW and the quiescent current drain is below 1 mA. The circuit can be easily assembled on a veroboard. For easy assembling and maintenance, use an 8-pin DIP IC socket for TDA2822M.

Infrared Alarm Barrier Circuit

This infrared alarm barrier can be used to detect persons passing through doorways, corridors and small gates. The transmitter emits a beam of infrared light which is invisible to the human eye. The buzzer at the output of the receiver is activated when the light beam is interrupted by a person passing through it.

Wireless Light Switch Circuit

You may use this wireless light switch instead of physical contact with switches which may be dangerous if there is any shorting.
The wireless light switch circuit described here requires no physical contact for operating the appliance. You just need to move your hand between the infrared LED (IR LED1) and the phototransistor (T1). The infrared rays transmitted by IR LED1 is detected by the phototransistor to activate the hidden lock, flush system, hand dryer or else.
This wireless light switch is very stable and sensitive compared to other AC appliance control circuits. It is simple, compact and cheap. Current consumption is low in milliamperes. The circuit is built around an IC CA3140, IRLED1, phototransistor and other discrete components.
The working of the circuit is simple. In order to switch on the appliance, you simply interrupt the infrared rays falling on the phototransistor through your hand. During the interruption, the appliance remains on through the relay…

Mobile Solar Charger

Here is an ideal mobile charger using 1.5 volt pen cells to charge mobile phone while traveling. It can replenish cell phone battery three or four times in places where AC power is not available.

Most of the Mobile phone batteries are rated at 3.6 V/500 mA. A single pen torch cell can provide 1.5 volts and 1.5 Amps current. So if four pen cells are connected serially, it will form a battery pack with 6 volt and 1.5 Amps current. When power is applied to the circuit through S1, transistor T1 conducts and Green LED lights.When T1 conducts T2 also conducts since its base becomes negative. Charging current flows from the collector of T1. To reduce the charging voltage to 4.7 volts, Zener diode ZD is used. The output gives 20 mA current for slow charging. If more current is required for fast charging, reduce the value of R4 to 47 ohms so that 80 mA current will be available. Points A and B are used to connect the charger with the mobile phone. Use suitable pins for this and con…

Launching the brand-new GaN-template product from Hitachi Cable

Hitachi Cable, Ltd. hereby announces that it has developed a new mass-production technology for GaN-templates (Fig. 1), in which a high-quality gallium nitride (GaN) single-crystal thin film is grown on a sapphire substrate, and it will start selling these templates.
Using this product as a base substrate for an epitaxial wafer for white LEDs (hereinafter referred to as "epiwafer for white LED epiwafers") makes it possible to drastically improve productivity of white LED epiwafers and the LED properties. Therefore, this product is expected to become an effective solution to improve the position of white LED manufacturers in the industry, where there is severe competition.

The demand for white LEDs is rapidly expanding and they have come to be used in backlight unit in liquid crystal displays (LCDs) and ordinary lighting devices in recent years thanks to their energy efficiency and long service life. The structure of an white LED epiwafer consists of a thin act…

Continuous monitoring of UV exposur

UV lamps are used to cure coatings and adhesives in many industrial manufacturing processes. And special sensors are used to measure the intensity of the UV light applied to these surfaces. But because these sensors age too quickly, they can only be used to record intermittent measurements. Fraunhofer researchers have developed a new generation of sensors capable of continuously monitoring UV intensity. These devices will be presented for the fi rst time at the Sensor + Test trade show in Nuremberg, from May 14 to 16 (Hall 12, Booth 537).
“UV exposure” is a term that tends to ring alarm bells, as most people associate it with unpleasant consequences such as sunburn and the risk of skin cancer. But ultraviolet (UV) light can also be benefi cial, or indeed essential: the human body needs it to produce vitamin D. Industry, too, makes use of UV light, for example to cure adhesives or the coatings applied to food packaging, and also to disinfect water. On the other hand, su…

The printed & flexible electronics market will reach ~$950M in 2020 with a 27% CAGR in market value, estimates Yole Développement

Yole Développement announces its Flexible Applications Based on Printed Electronics Technologies 2013 report. Yole Développement’s report provides up-to-date market forecast 2013-2020, roadmaps and timelines for printed, flexible, and printed & flexible applications. Also, it analyses the function vs. flexibility, current technical & economic challenges, manufacturing process and focuses on polytronics.
Technical challenges are close to being overcome to reach US$1B market by 2020
Today flexible & printed electronics create a lot of hope. And a supply chain is being created to support an industrial infrastructure. In its report, Yole Développement has identified and tracked the five main functionalities of flexible & printed electronics: displaying, sensing, lighting, energy generating and substrates. The different degrees of freedom in flexibility that can be obtained can be divided into:
• Conformable substrate: the flexible substrate will be shaped in a…

Engineers work to better monitor missile health

The Aviation and Missile Research Development and Engineering Center is leveraging micro-electro-mechanical systems research in a new application to detect potentially damaging vibrations encountered by missiles during handling, transport and operation.

Stephen Marotta, Engineering Directorate project principal investigator, said MEMS research has been ongoing at AMRDEC for many years and many different applications have been successfully transitioned from the lab to the Soldier in the field.

In an effort to improve missile health monitoring, Marotta began collaborating with Mohan Sanghadasa, from AMRDEC’s Weapons Development and Integration Directorate, and Stephen Horowitz, an engineer with Ducommun Miltec.

The AMRDEC team is using technology, both current and in-development, to design a new MEMS sensor that will offer several benefits over current missile health monitoring systems.

We’ve spent a number of years developing acoustic sensors, microphones based on piezoe…

InvenSense® introduces world’s smallest dual-axis gyroscopes for optical image stabilization in smartphone

InvenSense, Inc. (NYSE: INVN), the leading provider of MotionTracking™ devices, announced the IDG-2030 and IXZ-2030 dual-axis Optical Image Stabilization (OIS) gyroscopes.

OIS eliminates the effects of hand jitter to achieve blur free images and jitter free HD video. The benefits of OIS are most evident in low light conditions where longer exposure times are required. The IDG-2030 expands the dominant position established by the IDG-2021 in the OIS market. At 2.3x2.3x0.65mm, the IDG-2030 sets a new standard for size, profile, and power consumption. The IDG-2030, enabled by InvenSense’s patented technology platform, provides a 41% foot print reduction, 28% lower profile, and 50% lower power than the nearest competitor.

The first wave of OIS enabled smartphones has already hit the market with image quality rivaling high performance digital cameras,” said Ali Foughi, Vice President of Marketing and Business Development at InvenSense. “As the leader in this market, we are …
In a paper to be published in an upcoming issue of Energy & Environmental Science (now available online), researchers at the U.S. Department of Energy's Brookhaven National Laboratory describe details of a low-cost, stable, effective catalyst that could replace costly platinum in the production of hydrogen. New material is a promising alternative to costly platinum catalyst The catalyst, made from renewable soybeans and abundant molybdenum metal, produces hydrogen in an environmentally friendly, cost-effective manner, potentially increasing the use of this clean energy source.

The project branches off from the Brookhaven group's research into using sunlight to develop alternative fuels. Their ultimate goal is to find ways to use solar energy—either directly or via electricity generated by solar cells—to convert the end products of hydrocarbon combustion, water and carbon dioxide, back into a carbon-based fuel. Dubbed "artificial photosynthesis," this …

Novel technique to observe nanoparticles in a liquid environment

The macroscopic effects of certain nanoparticles on human health have long been clear to the naked eye. What scientists have lacked is the ability to see the detailed movements of individual particles that give rise to those effects.


This technique will allow, for the first time, the imaging of nanoscale processes, such as the engulfment of nanoparticles into cells. In a recently published study, scientists at the Virginia Tech Carilion Research Institute invented a technique for imaging nanoparticle dynamics with atomic resolution as these dynamics occur in a liquid environment. The results will allow, for the first time, the imaging of nanoscale processes, such as the engulfment of nanoparticles into cells.

Nanoparticles are made of many materials and come in different shapes and sizes. In the new study, Kelly, an assistant professor at the Virginia Tech Carilion Research Institute, and her colleagues chose to make rod-shaped gold nanoparticles the stars of their new m…

Improving materials that convert heat to electricity and vice-versa

Thermoelectric materials can be used to turn waste heat into electricity or to provide refrigeration without any liquid coolants, and a research team from the University of Michigan has found a way to nearly double the efficiency of a particular class of them that's made with organic semiconductors.

Improved properties of PEDOT:PSS for thermoelectric applications Organic semiconductors are carbon-rich compounds that are relatively cheap, abundant, lightweight and tough. But they haven't traditionally been considered candidate thermoelectric materials because they have been inefficient in carrying out the essential heat-to-electricity conversion process.

Most efficient thermoelectric materials are made of relatively rare inorganic semiconductors such as bismuth, tellurium and selenium that are expensive, brittle and often toxic. Still, they manage to convert heat into electricity more than four times as efficiently as the organic semiconductors created to date.

Thi…
The viscosity of a fluid is a measure of its resistance to gradual deformation by shear stress or tensile stress. For liquids, it corresponds to the informal notion of "thickness". For example, honey has a higher viscosity than water . Viscosity is due to friction between neighboring parcels of the fluid that are moving at different velocities. When fluid is forced through a tube, the fluid generally moves faster near the axis and very little near the walls, therefore some stress (such as a pressure difference between the two ends of the tube) is needed to overcome the friction between layers and keep the fluid moving. For the same velocity pattern, the stress is proportional to the fluid's viscosity. A liquid's viscosity also depends on the size and shape of its particles and the attractions between the particles
A fluid that has no resistance to shear stress is known as an ideal fluid or inviscid fluid. In the real world, zero viscosity is observed only …

Embeded Server

Miniature embedded device server is a complete internet server built into an ethernet (RJ-45) jack. A device embedded with a fully integrated miniature device server can provide the internet data communication capability such that
The user can access the device setting through a standard internet browser. The manufacture can upgrade the system software / firmware of the device via the internet. The technical support personnel can do remote configuration, monitoring, and troubleshooting, including real-time device performance notification without in-house service visit. A dedicated co-processor, if available in the device, can be used to optimize network activities, permitting the host microprocessor to function at maximum efficiency. For example, if the miniature device server is embedded in every house appliance, one can easily do the following:
Schedule the recording time of VCR, pay-per-view or video-on-demand programs on the more user friendly internet browser. Coordinate t…

NCAP Display

Unlike most LCDs which are difficult to read in bright sunlight, the NCAPTM Plastic Liquid Crystal Display (Polymeric LCD) actually gets easier to read in brighter light (just like a piece of paper). For informational displays with many separately controlled segments (such as a digital clock), each part of the liquid crystal panel can selectively be turned 'on.' Furthermore, the amount of translucency is proportional to the voltage applied.
The heart of the NCAPTM technology is the liquid crystal cell. Normally this cell is black, allowing almost no light through. But when a current passes through it, instantly it turns transparent. Behind this liquid crystal cell is a colored reflective pattern. When the cell turns transparent, the colored print beneath shows through. HomeMembershipMagazinesForumSearch MemberCalculators
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