Carolyn Mathas writes:
The LT3763 by Linear Technology is a synchronous buck LED driver controller that delivers more than 300W of LED power. With an input voltage range of 6V to 60V, it targets such applications as automotive, industrial and architectural lighting. Output voltage from 0V to 55V enables it to driver LEDs in a single string. The driver features input and output current monitors and limiting and accurate input and output voltage regulation.
Buck LED driver delivers 300W of power - [Link]
LT series LED drivers with 10-100W power represent a complete solution with wide possibilities of control. Exceptionally narrow and slim design, remained even at high-power versions, provides a high flexibility of use.
Power supplies for LED lighting (so called drivers) are available from many producers, in a various qualitative level. Why to decide just for the LT series from German company Friwo? Here are few reasons:
- precise design, safe operation and a long lifetime
- voltage and current regulation in one device
- high efficiency and a possibility of dimming in a range of 0-100% directly via a CTRL pin
- modules are available in 10-100W power, with a possibility of customization by laser directly at production also available a module for dimming – so called DIMMbox, further expanding possibilities of control (switch, 1-10V, DALI) and with a possibility of synchronization with up to 1000 slave units
- very small cross section of modules (21x30mm, resp. 24x30mm at LT100) – applicable even in very tiny conditions
Wide control possibilities of LT series modules are perhaps the most interesting. Modules contain a galvanically isolated CTRL input, by which it is possible to switch on/ off the module without disconnecting from 230V mains. CTRL pin also serves for regulation of an output current. For this purpose, only one resistor (or a potentiometer) is necessary – connected between SEC+ and CTRL pins, with a value counted by a simple formula in the datasheet. The output current can also be controlled by an external voltage in the range of 0-1,8V connected to SEC- and CTRL, as well as by means of a PWM TTL (0/5V).
Further possibilities of control are provided by a standalone additional module DIMMbox. DIMMbox operates as an (almost) lossless PWM regulator with a MOSFET switched at f=600Hz. DIMM-BOX connected to any series LT driver enables to regulate an output current in a range of 10-100% or 0% (OFF) via a usual switch (switch-dimm“ mode), via a linear voltage 1-10V and also a DALI interface. DIMMbox tests after switching on, which of three methods of control is used and consequently accepts only signals from a given input – until switching off the module. DIMMboxes can be connected through SYNC inputs, ensuring the same level of dimming for all modules. Enclosed pictures will provide you the best idea about possibilities of connection.
Friwo drivers not only drive your LEDs but even control them - [Link]
Steven Keeping writes:
Lithium-ion (Li-ion) batteries have become popular for portable electronics such as laptop computers and smart phones because they boast the highest energy density (capacity per unit volume) of any commercial battery technology. Other benefits include thousands of recharges and no occurrence of the “memory effect” that plagued early nickel cadmium (NiCd) rechargeable cells.
However, it has been a tough design challenge to get the technology to where it is today. Lithium is a highly reactive material that can, for example, burst into flames if it comes into contact with water. Engineers and scientists have worked hard to develop novel compounds that can leverage the advantages of lithium while producing inexpensive, reliable, and safe batteries.
A Designer’s Guide to Lithium Battery Charging - [Link]
Computer Precision for Power Tools @ NYTimes.com – [via]
WOODWORKING is a tricky skill to master. Students learn to measure carefully before they reach for a saw, and to cut as true to the design as hand and eye allow. But, even so, precise cutting is a painstaking job, full of pitfalls and mismatched moldings.
Alec Rivers, a Ph.D. student at M.I.T., guides a cutting tool through wood by watching a computer screen.
Now computers and their tireless calculations may bolster the skills of many people who want to create well-cut picture frames, inlays or furniture but lack the dexterity.
Alec Rivers, a Ph.D. student at the Massachusetts Institute of Technology, and colleagues have created a prototype for a compact, computerized addition to power tools that automatically performs precision measuring and cutting.
The system, which has a tiny camera, motors and a video screen, takes part of the pain out of woodworking, by using what Mr. Rivers calls “tool GPS.”
Computer Precision for Power Tools - [Link]
Stephen Evanczuk writes:
Energy-microharvesting applications such as wireless sensor nodes require periodic bursts of power well beyond that available in steady state from most ambient sources. In this respect, supercapacitors offer performance characteristics that are well suited for energy-harvesting environments. By combining supercapacitors with appropriate power and charge management circuitry, and using specialized devices from manufacturers including Linear Technology, Maxim Integrated Products, and Texas Instruments, engineers can exploit microharvesting techniques in applications with demanding peak power requirements.
Power Management ICs Simplify Integration of Supercapacitors in Energy Microharvesting Designs - [Link]
element14 has teamed up with top suppliers, including Texas Instruments, Wurth Elektroniks and Cadsoft, to launch a new wireless power microsite. Designed to accelerate the integration of wireless power solutions in popular applications, such as smart phones, digital cameras and more, the site gives engineers access to a wide range of technical experts, complimentary webinars, product roadtests, and safety and compliance standards.
Engineers are invited to learn more by registering for a free webinar – “Charging Innovation – Cut the Cord” – on Thursday, Sept. 20 at 3 p.m. GMT/9 a.m. CDT. Attendees will see a demo of the new microsite, an overview of wireless power reference designs, and an opportunity to have questions answered during a live Q&A session following the webinar.
Wireless power integration made easy with TI’s bqTESLA evaluation modules - [Link]
Brian Chu writes:
Batteries often serve as the main energy source for portable electronic devices. Although they depend on batteries, portable consumer electronic products, such as GPS devices and multi-media players, often consume energy directly from an ac-dc wall adapter or accessory power adapter (or “Auto Adapter”) when the battery is low or the device is in a stationary mode. Due to their cost effectiveness over their useful life, rechargeable batteries are often used for the power source of the portable electronic device. Attributes such as “relatively high energy density” and “maintenance free” make Lithium-Ion (Li-Ion) batteries popular in the portable consumer electronic products. Refer to the application note, AN1088, “Selecting the Right Battery System For cost Sensitive Portable Applications While maintaining Excellent Quality” (DS01088) for characteristics of Li-Ion batteries. Some examples of how to properly design with Li-Ion batteries will be discussed in this application note.
Designing A Li-Ion Battery Charger and Load Sharing - [Link]
Shawn Rhen writes:
The advancements in high powered LEDs have brought them to the attention of the lighting industry, positioning them as replacements for the current incandescent and fluorescent technologies. Although widespread adoption has not yet come to fruition, opportunities exist in which these present lighting technologies are unable to compete, a fact that has been realized by lighting architects for years.
Most prevalent is the ability to produce multi-colored illumination for accent, automotive, and signage applications. It is this aspect of high powered RGB LEDs on which we will focus.
In order to produce consistent and repeatable colors, the first design criteria that must be met is that of a constant drive current for each of the RGB die. As shown in Figure 1, this is accomplished utilizing 1 amp maximum constant current drivers that are adjustable with trimmer potentiometers and powered from a 5 volt DC supply.
High Power RGB LED Color Mixing - [Link]
Don Scansen writes:
For any complete energy-harvesting system designed to provide power to anything but small, short-duration loads, storage batteries represent a necessary but significant portion of the initial expense. The cost of batteries over the lifetime of the system can have an even larger impact if care is not taken to maximize the useful life of the battery component. What’s more, if unit growth continues for photovoltaic and other energy-harvesting systems relying on large-capacity storage batteries, designs that fail to maximize battery life could have a negative environmental impact due to the extra material and energy consumption needed to manufacture replacement systems as well as dispose of exhausted units.
Charge Controller Design for Maximum Battery Lifetime in PV Systems - [Link]
Texas Instruments has announced the introduction of the PowerLab Reference Design Library, a collection of power management reference designs. The reference designs include relevant technical documentation, such as circuit schematics, printed circuit board layouts, lists of components and materials, Gerber files, and other design support tools.
The library holds more than 300 power management reference designs for a variety of both isolated and non-isolated power conversion topologies suitable for lighting, telecommunication, computing and consumer electronics applications.
An interactive search tool is available on the website and new designs will be added to the database each month. [via]
Power Management Design Library Opens its Doors - [Link]