Category Archives: Newsworthy

DC-DC converter with increased efficiency & reduced noise

The new Synchronous Buck-Boost DC/DC converter LTC3111 available from Linear Technology is very significant in many respects. The most important factor being that it is able to operate at 95% efficiency and that too at a very low noise level. It can give a power output of 1.5A when used from a very wide range of power sources. These include multiple or single cell batteries, wall adapter and super-capacitor stacks. This convertor accepts 2.5 to 15V as the input and outputs 5V with the regulated output converted at almost 95% efficiency. Its noise reduction technology ensures that LTC3111 operates at a reduced level on a continuous basis at both buck or boost transitions. This convertor is considered ideal for all applications that require power output at a constant level without noise when the input is varying.

In many areas of operation, where battery life is to be extended by step down solutions, this convertor offers a straightforward solution. This is done by synchronizing the default 800KHz frequency to an external 600 KHz to 1.5 MHz clock. LTC3111 has a proprietary feature of the third generation that gives maximum efficiency at a very low noise level. That reduces the use of external components, which makes the solution offered extremely compact in all respects.

The LTC3111 has four N-channel MOSFETs with very low on-state resistance and the efficiency of 95% is achieved with the use of a single inductor. The Burst Mode is user selectable and this operation impressively lowers the quiescent current down to only 49µA. That enhances the light-load efficiency and significantly improves the battery run time. The burst mode has the option of being disabled whenever the operation is for noise sensitive applications. The output can be disconnected from the load; it has over voltage protection and short circuit protection. A thermal shutdown feature is one of the main advantages of this LTC3111 convertor.

These converters are offered in the market with several variations in packaging. The 14-lead 3mmx4mm DFN package is identified as LTC 3111EDE. Thermally enhanced 16 lead packages are also available and identified as LTC3111MSE. The pricing has been kept competitive. The industrial grade component with an operating junction temperature range of -40 to 125°C is priced slightly on the higher side. Further, higher operating temperature convertors that range from -40 to 150°C are also being offered at special prices. The same converter versions with high reliability are also on offer. Their operating temperature range is from -55 to 150°C. Most significantly, all the versions are available for immediate shipping and discounts are given for bulk quantities.

Notably, the Synchronous Buck-Boost DC/DC converter LTC3111 launched by Linear Technology is significant for both industrial and domestic applications. It is able to achieve an optimum output of 95%, even when the power input is from different sources. The noise level is also considerably reduced as compared to other similar products in the market. This converter is the answer for optimum performance for all noise-sensitive applications. With ready-to-ship availability, this product will find a number of users.

Cubli the Baron Munchausen of Robots

When you find a cube lying innocently on the table, you wouldn’t exactly expect it to jump up and start balancing itself on its edge or on its corner, will you? Probably not, if it wasn’t Cubli, the one designed at ETH Zurich. Well, it does not actually lift itself up by its own locks as Baron Munchausen was fond of doing, but Cubli the robo-cube can bring a smile on your face when you see its capers – watch its antics below.

Cubli, the 15x15x15 cm cube, has several spinning wheels and motors inside it. The contraption lets Cubli lie on one of its sides peacefully, then jump up to stand on an edge and proceed to tilt for balancing itself on one of its corners. By combining its jumping and balancing tricks, Cubli can even walk!

A closer inspection reveals three reaction wheels within the cube, one on each axis. These are able to spin at high speeds, as they have a motor each to drive them. The combined reaction of the three spinning wheels makes Cubli attain its uniquely stable postures. In fact, the positions are so stable that you can even nudge Cubli a little and it will resist falling over. Cubli can control its fall, allowing it to “walk” on a surface.

To control the speed of each of its wheels, Cubli has three motor-controllers, governed by an on-board processor and a bevy of inertial sensors. The motor-controllers rev up their individual motors based on the commands from the processor. Sensors monitor the tilt and angular velocity of Cubli at different points and feed this data to the processor to compute how fast each of its reaction wheels needs to spin to get Cubli to maintain its position.

By suddenly stopping the spinning of one of its reaction wheels, Cubli can jump up to one of its edges from its resting position and similarly, proceed to balance itself on its corner. Satellites use the same technique to keep themselves stable in orbit and Segway keeps you from falling off its scooter. However, the algorithms that Cubli uses are entirely different.

It feels funny watching Cubli walking. From its resting position, it rears itself up on its edge, hangs there for a moment and then gradually lowers itself on to the next side, repeating this sequence for its controlled walk. When Cubli is balancing on its edge or its corner, it will maintain its balance even if you tilt the surface on which it is resting.

All this is made possible because the spinning wheels act as gyroscopes. The momentum of the spinning wheels keeps the cube balanced. When one of the wheels slows down, it loses its momentum, and the center of gravity of the cube starts to pull it down. Speeding up the wheel improves the momentum and counterbalances its center of gravity, allowing Cubli to regain its position.

Another research group is considering using this amazing technology for building robots and using them for exploring other planets.

Haptics: A sense of touch through the computer screen

Touch-screens are quite common in mobiles, smartphones and tablet computers nowadays. They allow us to control and command the computer according to our requirement. A sense of touch is something different; it is sensing an object displayed on your computer screen. Imagine seeing a rose on your computer screen and by reaching out with your fingers, feel the softness of its petals.

This amazing possibility is the result of a non-mechanical haptic interface that allows computer users to manipulate a three-dimensional object on the screen of a computer to receive tactile response from the surroundings of the object. In short, you can reach out to touch and feel the object displayed on your computer.

The haptic interface uses flotor, a device shaped like an inverted umbrella and it contains coils of wire. It also has a control handle, which the user moves to interact with powerful magnets underneath. Electronic circuitry transfers the motion on to the screen that responds when an object collides with anything in the virtual world.

Normally, you are able to see and hear the information displayed on your computer screen. Touching the image to feel its texture and movement was not an option until now. At Carnegie Mellon University of Pittsburgh, PA, Dr. Ralph Hollis is working on his specialization, haptics – the science and technology of touch.

The user has to grasp a handle inside a sphere that is attached to a desktop computer. The handle connects to an object that looks more like an upside-down umbrella and it is called a flotor. The flotor carries electrical current flowing through electrical coils. All this is immersed in a powerful magnetic field, created by several permanent magnets.

Normally, the magnetic field allows the handle to float freely inside the sphere. The user can move and rotate the handle to control the position of a 3-D object on the computer screen. As soon as the object touches something in the virtual world, the user can immediately feel it.

Although there are many other haptic devices around, the concept of grabbing a motorized arm to interact with the computer is unique. Dr. Hollis has used magnetic levitation to make a direct connection between the user’s hand and the software. The result is direct and immediate feedback.

Briefly, haptics brings touch within a digital environment. This may give you the feel of resistance when you use a joystick in a game or give you touch sensation when using gloves in a virtual reality environment. Using haptics, the user gets an instant feedback when an object collides with another and does not have to rely only on what he sees. You can estimate what it feels like when you have to walk when your foot has fallen asleep. Adding the feeling of touch to a virtual environment makes interactions more life-like and similar to the benefit you have when you have full feeling in your feet.

At present, haptics works only with objects that are magnetic by nature, that is, objects attracted by magnets.

Using the Texy’s Mini TFT Screen for Your Raspberry Pi

The single board computer, the Raspberry Pi (RBPi) is a wonderful device, but it needs a screen for you to see what it is doing. The Mini TFT screen from Texy’s is just made for the RBPi and the kit comes in a beautiful Perspex box too, which makes it very smart and practical. The Perspex box has a neat slot in the corner for the RBPi-Camera, although you may have to add blu-tack to prevent the camera from popping out. The screen and display are pre-built and ready to plug into the RBPi GPIO socket.

The display is backlit TFT, measuring 2.8-inches. The resolution is 320×240, which is a quarter VGA or QVGA, with 64 thousand colors. The current consumption is a mere 99mA. A major portion of this current is on account the backlight, which consumes 85mA. That means, if you switch the backlight off, by setting P1 on Pin18 to low, this screen uses only 19mA, which is great for battery-powered applications.

If you compare this with the 9-inch DVD player screen, which is 640×220 in resolution, and runs from the RBPi Analog output, the Texy’s screen is much sharper and more usable. Note that the standard TV resolution is 720×480 or 720×576. The digital connection makes the RBPi desktop very clear, perfectly formed and very easy to read on the small TFT screen.

The Texy’s screen provides a useful terminal display, fully displaying the entire RBPi desktop. Although it may not run full speed frame-rates, the display shows video perfectly. The compact fonts get a lot of text displayed on the terminal despite it being only 2.8-inches.

The addition of the resistive touch screen is the magical bonus as this opens up a great multitude of project possibilities, where a mouse, full keyboard and display setup would be rather impractical. You can bring the touch panel alive by combining some python code and Tkinter to get a very effective touch-based control system for your RBPi.

Texy’s has added flexibility to the screen in the form of the PI header pass-through available on the display board. You can use a ribbon cable to link the display to the RBPi GPIO and use the GPIO connections on the underside of the display. Alternately, you can connect the display directly to the RBPi GPIO and extend the GPIO with the cable.

Since the display uses SPI interface pins on the GPIO, including CE0, CE1, GPI00, GPI01 and GPI06. The GPIO pass-through allows you to connect your own ribbon cable to add further hardware, which can use the rest of the GPIO pins. A convenient GPIO pin out key is printed on the board for reference.

The easiest option for most is to use pre-configured images for driving the Texy’s display. Others, who are more confident, can modify the existing OS to use the screen; it is suggested to make a backup before setting out. Follow instructions here.

The display case, while providing support to the display unit, also extends out providing protection to the SD-Card while allowing full access to all sockets and connections of the RBPi.

Ultra-dimmable first retrofit premium 850 lumens LED lamps

Ledzworld, the Netherlands Company based in Amsterdam, has launched the world’s first ultra-dimmable retrofit LED lamp producing 850 Lumens from a single source. The product AR-111 LED lamp has been developed with several notable features incorporated with the user in mind. Ledzworld is a world-renowned company that has been a pioneer in harnessing LED technology and it is no surprise that they have come out with these LED lamps to be used in various places. This innovation is considered as an ideal replacement for the halogen lamps that has been in use for a long time now. The AR-111 LED lamp is well tested, cost effective, highly efficient and the design is perfect for the user, makers, designers and installers.

AR-111 is a single source LED lamp that comes with a CRI of 80. It is also offered with a CRI of >90. It also has the company’s special Chameleon Driver, which is a technological breakthrough that has the self-adjusting feature to make it a perfect fit. It can be used with a variety of combination of drivers and dimmers. The Chameleon Driver detects the transformer type initially and then it goes on to analyze the waveforms to suitably change or transform itself into a perfect fit.

Jan Kemeling is the founder and the Chief Sales and Marketing Officer of Ledzworld. He says, “A large number of current luminaires on the market with integrated LED light engines look bulky, but Ledzworld’s unique AR-111 Platinum Ultra Dimmable LED has the appearance and characteristics of a sophisticated track-luminaire while efficiently delivering 850 Lumens.” The looks are aesthetic and match perfectly with the ambience of museums, lounges, hospitals, hotel, residential, retail displays and restaurants. Kemeling also opines, “This innovative Chameleon Driver makes our AR-111 Platinum LED lamp a true ‘plug and play’ solution that can be trusted with no surprises or disappointments.”

The AR-111 has the intelligence to monitor the temperature within its driver compartment. The beam angle can be adjusted to 25 degrees or to 40 degrees, with the help of Reduced Glare Optical Technology developed by the company. The lamp comes with three-color temperatures of 2700K, 3000K, and 4000K. It has an overall dimension of 62×111 mm with light of single focus. When compared with halogen lamps, AR-111 allows a saving of 80% of the energy consumed. The removable outer ring is patented for the product and it allows the option of matching the color to the application or fixture. Ledzworld offers a three-year warranty for continued usage of this LED lamp.

Given the company’s global reputation in manufacturing LED lamps, this ultra-dimmable AR-111 LED lamp is bound to play a path-breaking role in its use. It offers several benefits by way of energy saving, operational efficiency, convenience in use along with its robust features. The most important aspect of the product is that it is a replacement for halogen lamps that are still used very widely. This effectively means that users gain cost wise as well in its operational efficiency.

Special heat sinks for heavily populated boards

Designers have to manage airflow carefully when solving the task of cooling heavily populated PCBs or Printed Circuit Boards. For effective cooling, the movement of airflow along the board is important. Two factors play a crucial role when selecting and qualifying heat sinks for dense PCB applications. The first factor is thermal resistance and the other pressure drop.

Thermal resistance is the increase in temperature in degrees Celsius for every watt and it measures how effectively the heat sink transfers heat from the heat-generating device to the ambient environment. A better heat sink has a lower thermal resistance. In other words, a better heat sink offers lower resistance to heat flow, such that it can cool hotter objects faster. Another way to say the same thing is heat sinks with lower thermal resistance cool hot devices before they reach their maximum allowed temperature. For any heat sink, its thermal resistance value depends on the airflow over the heat sink. Faster airflow results in lowering the thermal resistance values.

Pressure drop, the other factor, is the resistance the air faces while moving through the fins of the heat sink. This is the difference in the airflow speed as it enters the array of fins of the heat sink to the airflow speed of the air as it exits the array. If the pressure drop is more, it means the heat sink is taking up more air for its own heat removal, leaving less air for the other devices on the board. Therefore, with heavily populated boards, designers must balance the low-pressure drop and the low thermal resistance for a heat sink. This requires a good understanding of the relationship among pressure drop, airflow, heat sink fin-density and heat sink performance.

The performance of a heat sink is highly dependent on the speed of the air stream approaching the heat sink. Air, being a bad conductor of heat, tends to move slowly while circulating on the surface of the heat sink. A faster air stream pushes the hot air away from the heat sink and lets in cooler air, resulting in better heat removal. For heat sinks that have many fins, air remains trapped within the fins because the low speed of the incoming air does not move the hot air away from the fins. Therefore, to enable a densely populated heat sink perform efficiently, forced air cooling is necessary; this improves thermal resistance more than 100 times in certain heat sinks, compared to natural convection cooling – that is, cooling without airflow.

When the board contains only one heat sink, the selection is simple as the thermal resistance of the heat sink is the predominant factor. For multiple heat sinks on a board, the allocation of available airflow along the board takes predominance. All heat sinks on a densely populated board, apart from affecting the device that each resides on, also affects the neighboring devices. Therefore, for proper selection of a heat sink depends on both its thermal resistance and its pressure drop.

Possibilities of harvesting triboelectricity

Although we already harvest energy from many sources, new sources are always welcome. Ignoring the up-front costs, harvesting energy is often free, convenient and eases problems of several types of practical installation and replacement. Energy harvesting requires three fundamental stages: a reliable source of energy, the harvesting electronics or the converter and a load where the energy can be gainfully employed.

Apart from finding a reliable source of energy, there is one other factor before the energy goes into the converter and load. This factor is the transducer, which will allow the energy to be gathered with reasonable efficiency and reliability. Suitable transducers examples are blades for airflow, piezo-based components for vibrations or a water-driven vehicle using temperature gradient for propulsion.

Currently we use several potential sources of energy for harvesting. Prominent among them are solar radiation, temperature difference, sound, vibration, airflow and motion. One of the most common sources that have been very hard and baffling to capture is static electricity generated from friction (also referred to as Electro Static Discharge or ESD). Generally famous for the damage it causes, triboelectricity it may finally have been tamed by the work done at the Georgia Institute of Technology.

Although a precursor to generating and collecting static electricity does exist in the form of the Van De Graaff generator, the team from GIT has developed polymer materials, which are inexpensive and flexible. In addition, these materials are very good at developing a charge through rubbing and holding it until it is extracted as current flow. Static electricity is easy to generate – simply walking on carpet is good enough – and hold – that is, until you touch the doorknob – but very tricky to extract.

The team generates power from triboelectricity by sliding two materials together and then separating them to create a gap in between. Although this may be interesting, the next question could be a tricky one – how much harvestable energy does this mechanism offer?

The GIT press release cites power outputs of the order of 300W, which is of course, significant. However, there is another side to energy harvesting. This concerns power delivery to the load. Although energy collection may happen in dribbles on the generation side, when releasing energy it to the load, it has to be done in the form of power, which is the rate at which energy is expended.

The reason for this is not hard to fathom. All loads require a minimum threshold or power to function. The 300W generated may translate into barely meaningful power levels at the load. When energy levels to be harvested are on the low side, it may actually be difficult to collect enough power after accounting for acceptable losses.

The team from Georgia Tech has done something impressive and intriguing. They claim that the materials they have developed have a volume power density of more than 400KW per cubic meter and the efficiency figure is more than 50%. In addition, the team says that their material is suitable for generating energy from contact with flowing water. That is an interesting proposition, opening up new opportunities where sinks and faucets could become the hidden sources for charging mobiles and or lighting up the kitchen.

Newly launched APT Power Transducers measure three phase current & voltage

NK Technologies, the San Jose, CA based American company has introduced an APT power transducer that is able to measure three phase currents and voltages. As per the industry norms, it generates an analog signal in proportion to the watts used. The product utilizes current transformers to measure load amperage and transducers to measure the line voltage, which can read up to 600 VAC. The power transducer is a compact unit and can be used in very widely different applications in multiple places. NK Technologies has been focusing on innovations in the area of cost effective current sensing products.

The APT power transducers can be configured in multiple ways. They accept 5-Ampere secondary current transformers. Alternatively, they also accept the safer ProteCT low voltage output sensors. Irrespective of the type of current, by generating an accurate signal and helping to locate where there is excess consumption of energy, it permits reduction in demand through intervention. The users have the option of 4-20 mA, 0-5 or 0-10 VDC outputs. The APT power transducers are compatible with most of the automation systems. Significantly, the compatibility is due to the industry standard analog output.

This product has been developed with the user in mind and taking into consideration various applications. The APT power transducers are externally powered. This power transducer gives improved reliability in places where there are significant variations in voltage and current, where the power sags, as well as where there are fluctuations in voltage, which is very common,. This helps in adopting cost effective measures used overall in time and energy so that there is stability in the system. The APT power transducers are designed to meet these conditions. NK Technologies have introduced this transducer after extensive testing in their factory and after field trials with varying conditions of current and voltage.

The APT power transducers are easy to install whatever the location. This is because of its compact DIN mounted housing. The terminals in the transducers are clearly labeled, which enables easy and quick installation. The design is such that the cabinet depth is reduced significantly and it makes a low profile. The terminals are made safe for the person handling the transducer; the terminals are considered finger friendly. Effectively, it means that the connectors are safe and secure. World-renowned agencies such as the UL, CE and CUL, which everyone considers as rigorous and stiff in quality certification, have approved the APT power transducers.

With wide-ranging and need-based features and top class quality, the APT power transducers command worldwide acceptance. The company is at the forefront of Agency listings, Certifications and International Registrations for its manufacturing facility. This process has paved the way for innovation and customer requirements. The company offers warranty for all its products and along with it, a customer support considered the best in the industry. APT power transducers are all set to give the customer a new tool that is effective in terms of both cost and operational efficiency.

This 10 Watt blasting gun has intense illumination

The LED light application has now covered almost the entire gamut of all human activity. Larsen Electronics recently announced the launch of 10W LED blasting gun light designed to produce intense illumination up to 860 Lumens. The major highlight of this product is that it is IP-66 watertight, which gives it the capability to withstand the rigors of heavy-duty environmental applications. Larson Electronics has christened the product as BLG-LEDP1X10W blasting gun light and it is extremely durable in media blasting applications. This LED light can be mounted on any standard blasting gun stand with utmost ease for immediate use.

The mounting system is specifically designed to be easily setup and used on the barrel of any standard blasting gun. The system comes with the hardware needed for the mounting along with its protective lens cover. It can be easily removed or replaced, even when wearing gloves. This product is helpful in blasting environments such as sand, baking soda or coal slag. The lens may wear out in due course of time as it is exposed to blasting, but is easily replaceable. A slot provided at the bottom of the lens allows cleaning of particles when the lens is changed. The LED mounted on the blasting gun system can last for a considerable length of time.

With a 120-277V AC encapsulated transformer and 100-ft cable attached to it, the LED light operates on 24V DC. The step-down transformer converts 120-277V AC to 24V DC and provides the power needed for this LED light unit. It produces light of high intensity, about 860 Lumens. The light beam covers 600 feet and the manufacturer is assuring a lifetime of 50,000 hours. Meeting the IP66 watertight standards, the LED gun light is not only for heavy-duty applications, but also for aggressive use in the difficult terrains of atmospheric variations. Unlike other blasting gun lights, BLG-LEDP1X10W blasting gun light by Larson Electronics is lightweight but at the same time produces an intense light, which is brighter and produces more intense illumination when compared to the incandescent lights.

The gun lamp consumes only 10-Watts and the overall dimension of the unit is 3×3.8×4-inches, with IP 66 ingress protection and spot/flood light configuration. This LED light unit is mounted on the clamp on top of the blasting gun. The protective lens is made of quick-change polycarbonate. This unit comes without the blasting gun mount as the mount is to be procured separately.

BLG-LEDP1X10W from Larsen Electronics is seen as a new dimension to the illumination designed with the users in mind. It gives not only a viable lighting technology, but also durability in very rough and abusive work areas. It is durable while at the same time it generates an intense light of 860 Lumens. It is to be noted that this unit will replace all the instances where incandescent lamps were being used so far. With more innovations expected, LED lighting technology is all set to take over totally in all locations on a global basis.

A new 32 HD motor for rough operations

Maxon Precision Motors, Inc. based in Fall River, MA, has successfully designed a new 32 HD motor for rough and abusive operations. Known as the EC-4pole 32 HD motor with part number 397798, the motor is considered ideal for operating in conditions existing in deep drilling. Exploration in gas and oil fields is known by the name “downhole drilling” and according to deep drilling technology, it is possible to recover oil and gas even from depths of 2500 meters or more. This 32 HD motor is being offered for this application as it has been specifically designed for the purpose. According to the company, this 4-pole power motor uses a winding technology that is the best among the same class of motors in the field.

The performance in terms of the volume rate, in proportion to its weight along with the quality and security it is able to generate, is excellent due to the motor providing inertia free motion. The durability of the motor is astoundingly long. This factor alone has been the main feature for this motor, which has enabled the motor to cater to the application of deep drilling in a very significant manner. With wide ranging options for different types, as required by the user, the motor is able to meet the requirements for the purpose.

The motor has a power rating of 220W in air and graduates to 480W in oil due to the high heat flow that is generated in the process. The motor functions in an ambient temperature range reaching up to 200°C and more, with atmospheric pressures of up to 1700 bar. The notable aspect of this motor is its capability to bear vibration up to 25Grms along with impacts up to 1,000G. That means an impact that is effectively 1000 times the acceleration due to gravity at the earth’s surface. The operational efficiency of the motor is exceptionally high. The manufacturer claims an efficiency of 89% in air and 80% in oil.

The EC-4pole 32 HD motor from Maxon is 3-phase AC operated at a nominal voltage of 48V. The nominal speed of the motor is 5710RPM with the starting current at 47.5A, for an efficiency of 89%. It weighs only 860grams and the rotation is clockwise. The motor rotor produces inertia of 128 gcm² with a mechanical time constant of 2ms. The terminal resistance of the motor is 1.01 Ω. The maximum permissible speed is 12000RPM and the motor can take up a maximum axial load of 16N.

Maxon Precision Motors, with a global reputation in the field, expects the EC-4pole 32 HD motor to perform well in the field meeting the rigorous standards set for the deep drilling applications. With a wide range of options available to meet the specific needs, the 32HD motor will be able to function in rough operating conditions, where the depth is more than 2500meters. This motor makes it possible to recover gas and oil at a high level of efficiency. This highly durable motor performs in spite of multiple vibrations and severe impacts it undergoes.