oL   06                                                                                                                   ...
iSAY                                                                                                                      ...
This article discusses some of the high            systems, often this is not commercially                                ...
< Continued from page 07figure 3     topology                                  schematic                                  ...
PRoDUcT                                                                                                                   ...
ESD Protection Spend a Little – Save a Lot     ESD (ElectroStatic Discharge) is a significant threat to quality in the    ...
MAxIMISINg                       EffIcIENcY                       fRoM RENEWAbLE ENERgY SoURcES                       Digi...
ePurchasing          Innovations       for Switched-on                       Supply chain Management                      ...
LeCroy WaveAce Oscilloscopes< Continued from page 16                            or prices, web-based purchasing tools now ...
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eTEch 5 - Balancing the Power Options.

Explore the latest issue and find out about Power efficiency for the modern electronics system, Fibre optic choices for today's energy challenges and ESD protection.

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  1. 1. oL 06 To Y Nc 24 P b c IE PoWER EffIc IcIENcY Eff 14 MAxIMISI g NWelcome to your latest edition of eTech. If you’ve scannedthe contents section of this issue of eTech our theme canhardly have escaped you.A startling statistic I came across recently is that the Earth absorbs more energy from thesun in an hour than the population of the world consumes in one year. In fact the amountof solar energy reaching the surface of the planet is so vast that in one year it is about twiceas much as will ever be obtained from all of the Earth’s non-renewable resources of coal,oil, natural gas, and mined uranium combined! The technologies that we have for extracting INSIDE eTechenergy from this and other natural sources are developing rapidly, and we are starting tosee the benefits. Projects like the prize-winning solar powered car on page 5 are turning 04 iSAYsceptics everywhere into believers. 05 RS NEWSLINEFor some electronic devices, renewable energy is already supplementing existing power 06 PoWER EffIcIENcYsources, and coupled with more efficient power design, this can greatly reduce the cost of 10 PRoDUcT NEWSoperation, or extend battery life. The mobile technology revolution now demands batteriesthat come close to matching the energy density of dynamite, so a “greener” battery 12 ESD PRoTEcTIoNtopped up via harvesting energy is desirable in more ways than one when you think aboutholding a smartphone up to your ear! 14 MAxIMISINg EffIcIENcY 16 ePURchASINg INNovATIoNS Power efficiency and renewable energy go hand in Terms and conditions: Terms and hand, and together are driving a further shift. 20 DESIgN REvIEW : EMbEDDEDconditions of sale set out in the current For environmental reasons, for economic reasons DEvELoPMENT WITh EDP 22 RS Catalogue. This issue is valid from January 2011 to March 2011. and for reasons of convenience, in the future I believe MARKET TRENDS : SoLAR MARKET that we will move on from thinking about simple Published by: RS Components Limited. Registered office: “power efficiency” to power “self-sufficiency” in 24 Pcb TooL Birchington Road, Weldon, Corby, our electronic designs. Northamptonshire NN17 9RS. Registered No. 1002091. RS 28 DESIgN TIPS : 3D LED PYRAMID Components Ltd 2010. RS are trademarks of RS I hope you enjoy this edition, which of course, 30 cUSToMER PRofILE Components Limited. An is consumed with powerful discussions about, Electrocomponents Company. yes, power. 31 REDUcINg ENERgY 32 ELEcTRoNIcS ExTRAS 34 fIbRE-oPTIc 36 DETEcTINg MoTIoN Glenn Jarrett 40 LUNch bREAK Head of Electronics Marketing 42 INDUSTRY NEWS : fRAUNhofERELE_0014_0111 eTech - ISSUE 5 03
  2. 2. iSAY RSAndreAs schneider, NEWSLINES“ technology?executive vP & Founder,enoceAn Gmbh, sAys: how to harness outstanding Sales RS sponsored team wins Award Presented to RS the Solar challenge Race components ” RS supports Tokai University solar car team the potential of energy harvesting Extension of relationship with EPcoS to win the race held in South Africa. results in outstanding sales This is their second successive victory at the SA Solar Challenge from Pretoria towards Cape Town, George and Mpumalanga to Pretoria. A total At Electronica in November RS components was distance of 4062km was covered with an average speed of 90.1km/hr in the 10 day challenge. delighted to be presented with the Sales Award for 2010 by EPcoS Ag. The award is presented each year to one The Solar Challenge is organized by the Advanced Energy Foundation and of EPcoS’ sales channel partners for outstanding growth the Innovation Hub. The primary aim of the Solar Challenge is to promote in sales in both the electronics and traditional side of the science and technology in South Africa and demonstrate the potential business based on online and NIc sales. of renewable energy sources to the motoring and other industries. over ten years ago Energy harvesting was known only to a small group RS Japan supported the supply of parts for the design and build of the car. of research engineers. but if you google it today you will find nearly two Announcing the award Peter Arch, Director Distribution Once the car arrived in South Africa, RS SA provided the chemical million hits and there is now a diverse range of energy-saving electronic at EPcoS commented, “We are very pleased with products to support the car. RS’ outstanding sales performance. The extension of products on the market that draw energy from their surroundings. our mutual product and service offerings has been Professor Kimura from Tokai University has personally thanked RS across the world for sponsoring for the Tokai University Solar car continuously. a success story, helping us to gain market share in a In building and industrial automation alone, the metres free-field range with a minimal energy challenging supply period.” find out more on this project on www.designspark.com opportunities for energy harvesting products are requirement of about 30 µJ for a single wireless inexhaustible. Particularly now, with the arrival of telegram. The process works with extremely short chris Page, general Manager, Electronics at RS wireless plug & play modules that work energy- telegrams, randomly controlled and repeated twice components continued, “The strengthening of our autonomously and bidirectionally. This means, for in the space of 30 milliseconds to avoid any collision. relationship with EPcoS over the last year has enabled example, that a room temperature sensor can transmit us to provide our customers with a wider product its telegram with the measured temperature value selection as well enhanced support services. We are and can receive a message for set point correction delighted this has resulted in this superb sales award.” “ ...the opportunities for along with the current time. To search the full EPcoS range All energy harvesting wireless sensors incorporate energy harvesting products visit rswww.com/electronics ” three essential functional blocks: electronic components (wireless technology, sensors and process control), are inexhaustible energy supply (energy converter, energy storage, energy management) and software (executive control, sensor STMicroelectronics MEMS profiles and wireless protocol). EnOcean, with its batteryless wireless modules, is Sensor range now available Employing mechanical or thermoelectric converters a pacesetter in the development of fully energy- STMicroelectronics and RS bring together an and solar cells instead of batteries is a unique autonomous applications in building automation. innovative range of motion sensing solutions approach, cutting system error rate and maintenance The technology is also gaining traction in industrial costs considerably. Further benefit is derived from the plants for reliable monitoring of machine status, STMicroelectronics’ MEMS sensors have revolutionized the way ability of the sensor to bridge periods when no energy simplification of cabling and retrieval of data from we interact with everyday technology, making it easier and more is available. Harvested energy is stored in a charge capacitor and can suffice for several days of operation inaccessible locations. user friendly by making electronic devices sensitive to motion. MEMS sensors allow smarter human-machine interfaces for vishay range expands in complete darkness. if you’ve got a strong opinion and would both consumer and industrial applications. to over 11,000 products like the opportunity to get on your soapbox, When it comes to wireless transmission, an optimum The MEMS sensors family available from RS, includes 2 and 3-axis RS and vishay announce new distribution agreement wireless protocol should combine maximum reliability write it up in around 300 words and email linear accelerometers to single and multi-axis gyroscopes, for high of transmission and proof against collision for 300 it to etech@rs-components.com performance and smarter power management. RS Components has concluded a European distribution agreement with Vishay which means that RS formally represents Vishay for detailed information, around the globe through three regional agreements. Vishay is one visit rswww.com/electronics of the world’s largest manufacturers of discrete semiconductors (diodes, MOSFETs, and infrared optoelectronics) and passive electronic components (resistors, inductors, and capacitors). RS has a stock profile of over 11,000 Vishay products available online for next-day delivery from capacitors and resistors to semiconductors. for more information visit rswww.com/vishay04 eTech - ISSUE 5 eTech - ISSUE 5 05
  3. 3. This article discusses some of the high systems, often this is not commercially level power architecture choices which viable since isolated power stages are Isolation are useful to consider at an early stage in generally more expensive than non-isolated Mains Psu #1 dc #1 the product design cycle. Choice of high converters. One alternative option is to level architecture has a significant impact use an intermediate bus architecture (IBA) Psu #2 dc #2 on the cost, efficiency and type of power whereby a front end high efficiency isolated topologies used to provide each of the converter steps the input power down Psu #3 dc #3 required power rails. to a safe low voltage which then powers secondary side power converters.The IBA Psu #4 dc #4 System Approach approach allows the majority of the system The power supply system for any product power converters to use non-isolated generally has a single energy source and topologies which saves significant cost. Intermediate Isolation requires many regulated DC outputs. The only downside of this approach is that DC Bus The energy source depends on the the energy delivered on most of the output Mains Psu #1 dc #1 product type but could be mains power, rails will experience power loss in two battery supply, telecoms DC input or a converter stages rather than one. In the case Psu #2 dc #2 renewable energy source. of the IBA shown in Figure 2, all the energy delivered on rails #2, #3 and #4 experiences Psu #3 dc #3 The power subsystem must normally loss in the front end converter PSU#1 as provide a number of key functions:- well as each respective secondary converter. Psu #4 dc #4 • Protect safely against abnormal Since the IBA approach is often chosen figure 2 conditions (faults in the product to minimise cost, there are a number Independent converter Architecture (Top) electronics or problems with the of guidelines which can be followed to and Intermediate bus Architecture (bottom) primary energy source) maximise the IBA overall system efficiency:- • Provided regulated voltages to the 1. Choose an intermediate bus voltage When considering the commercial product electronics independent of equal to the DC output rail with the implications of intermediate bus voltage changes in the primary energy source highest power requirement. This choice, it is good to remember that the or output load demand ensures that the largest possible secondary side converters with a high share of the total system power flows input voltage capability are likely to be • In many cases, provide galvanic isolation through a single converter stage. more expensive and have poorer efficiency between the primary energy source and than those where input voltage range is the product electronics 2. Where possible try to keep the low. Conversely, the conversion efficiency intermediate bus voltage just of the front end mains power converter • Control the power on/off sequence of slightly higher than the majority of tends to improve with higher intermediate the DC power rails as required by the the required DC output voltages. voltages. The best intermediate voltage product electronics This allows for the most efficient choice is often driven by a combination of conversion of the intermediate commercial and technical factors which are • Provide all the above functionality whilst bus voltage down to the DC unique to each product. For many products, wasting the minimum amount of energy output voltages. a good choice for system DC voltage rails of around +5V or lower is an intermediate In general the most energy efficient way 3. DC outputs with a very low load bus voltage of around 12V. The +12V outputPower Efficiency to provide each DC output is with a single compared to the total system load mains power converter often represents a power converter stage for each power will have minimal impact on the good compromise between commercial rail. In this case, the energy provided to overall system efficiency. Rails with and technical constraints for output power each output passes through only a single higher power requirements should levels up to around 60W. power stage and suffers only one stage of be used to justify a particular conversion loss. In the case of mains power intermediate voltage. Continued page 08 >for the modern electronics system Raw Power Regulated DC Voltages “ by Dr. Iain Mosely, Technical Director of Zonetech www.zonetech.com choice of high Primary Energy Source Power Subsystem Product Electronics level architecture hasModern electronic systems require an ever increasing number of different E.g. Mains AC, Automotive ??? E.g. FPGA μC, μP displays, ’s, , a significant impact DC, Telecoms, Battery, power amplifiers,system Dc voltage rails to operate. These complex power requirements Generator signal conditioning on the cost, efficiencycombined with a drive towards more energy efficient products and evershorter product design cycles can become a burden to companies and type of powerwho would rather focus resource on developing the key differentiatingtechnology of their new product. figure 1 – high Level Power System energy Flow topologies ”06 eTech - ISSUE 5 eTech - ISSUE 5 07
  4. 4. < Continued from page 07figure 3 topology schematic considerations Latest Innovation Miniaturized 2 Watt and 3 Watt DC/DC Converters • Fully moulded SMD- and DIP-Package Series VOUT<VIN, Efficiency degrades if VOUT is • Package Size 18.9 x 12.8 x 8.7 mm TDR 2: 2 W, DIP 24, 2:1 Input buck significantyly lower than VIN. • Wide Input Ranges 2: 1 or 4:1 TDR 2WI: 2 W, DIP 24, 4:1 Input cover 4.5 VDC through 75 VDC TDR 2SM: 2 W, SMD, 2:1 Input VIN VOUT • Tightly regulated Output Voltages • No minimum Load required TDR 2WISM: 2 W, SMD, 4:1 Input • Remote On/Off Function TDR 3: 3 W, DIP 24, 2:1 Input • 1500 VDC I/O-Isolation TDR 3WI: 3 W, DIP 24, 4:1 Input • Operating temp. Range -40 to 85°C TDR 3SM: 3 W, SMD, 2:1 Input VOUT<VIN, Efficiency better than Buck topology synchronous when VOUT is significantly lower than VIN. TDR 3WISM: 3 W, SMD, 4:1 Input buck Generally more expensive than buck. Semi-Regulated 1 Watt DC/DC Converters VIN VOUT • Compact SIP-Pachckage Series • Load regulation within 5% TRA 1: 1000 VDC I/O-Isolation • 1000 or 3000 VDC I/O-Isolation TRV 1: 3000 VDC I/O-Isolation • Operating temp. Range -40 to 85°C VOUT>VIN, Best effeciency when VOUT is not • Very high Efficiency up to 88% boost too far above VIN. Difficult to turn VOUT off due to DC current path through inductors and diode. Highest Power Density in DIP-24, 1“ x 1“ and 1” x 2” Package VIN VOUT • 6-side shielded Metal Casing Series • Wide Input Ranges 2:1 or 4:1 THD 15N: 15 W, DIP 24, 2:1 Input • Adjustable Output (except 15 W Models) THD 15WIN: 15 W, DIP 24, 4:1 Input • Remote On/Off Function THN 20: 20 W, 1“x 1“, 2:1 Input inverting Generates a negative voultage from a • Input Filter to meet EN 55022 Class A (buck boost) positive voltage. High peak currents can • Low standby Current THN 20WI 20 W, 1“x 1“, 4:1 Input degrade efficiency. • 1500 VDC I/O-Isolation THL 20WI: 20 W, 1“x 1“, 4:1 Input VIN VOUT(Negative) • Very high Efficiency up to 91% TEN 40N: 40 W, 1“x 2“, 2:1 Inputfigure 3 – Secondary Side non-isolated Topologies High Power DC/DC Modules 75 – 200 Watt Linear VOUT<VIN, simple but poor efficiency unless input • 2:1 and 4:1 Input Range Series regulator and output voltages are very close. • Output Voltages 5 to 53 VDC TEP 75WI: 75 W, 2.4 x 2.3“, 4:1 Input • Ultra high Efficiency up to 93% TEP 100: 100 W, 2.4 x 2.3“, 2:1 Input VIN VOUT • Series with EN50155 Approval for TEP 150WI: 150 W, 2.4 x 2.3“, 4:1 Input • Railway Applications • Multiple Options: Chassis / DIN-Rail TEP 160: 160 W, 2.4 x 2.3“, 2:1 Input Mount Adapter; EMI Filter; Heat Sink TEP 160WI: 160 W, 2.4 x 2.3“, 4:1 InputOnce the intermediate bus voltage has a significant challenge to designers who power) but this can hide which parts of a • Soft Start and reverse Input Voltage TEP 200: 200 W, 1“x 1“, 2:1 Inputbe chosen, the power topologies for the wish to maximise their new product product subsystem are really dominating Protection TEP 200WI: 200 W, 1“x 1“, 4:1 Inputmain isolated converter and secondary energy efficiency. Commercially, the IBA power consumption. Wouldn’t it be greatconverters can be chosen. For a 60W total architecture is often the best system level at design time if we could understand thepower capability with 12V intermediate bus approach but the choice of bus voltage and product power use at a much 100 W & 200W AC/DC Power Supplies with «cool» Designvoltage, a flyback converter can give good secondary side power converter topologies deeper level….?front end performance with conversion then has a significant impact on product • No Fan required at full Power Seriesefficiency of 85 to 90%. The topologies energy use. Key to minimising development up to 50°C! TOP 100: 100 W in 2” x 4” Formatused for the downstream converters risk is to use a flexible modular approach to • Excellent thermal Management for TOP 200: 200 W in 3” x 5” Formatdepend on the output voltages and system power design whereby the power long Product Lifetimepower levels required. system can be easily modified during • Highest Efficiency: 90% typ. the design process to optimise system Zonetech products will shortly • Protection Class l or Class ll Operationconclusions power use. Often, power consumption be introduced to the RS stockedThe complex power requirements of measurements are just performed on the product range. find them firstmodern electronic products can present primary energy source (e.g. mains input at rswww.com/electronics www.tracopower.com for full TRACOPOWER Product Range rswww.com08 eTech - ISSUE 5
  5. 5. PRoDUcT PRoDUcTNEWS NEWS Pv fUSES fRoM SchURTER high performance fuse for Pv systems with Touch safe fuseholder STEgo SMALL fAN hEATER high power compact fan heaters, n A new solar fuse ASo and fuseholder ideal for use where space is oxLEY LED LAMPS fSo from ShURTER with quick-acting at a premium New and exclusive to RS. Energy efficient characteristic to protect photovoltaic incandescent lamp replacements. n DIN Rail Mount Enclosure and similar Dc-applications. The PcI AND PcI ExPRESS MINI cARDS products are well suited for “renewable heaters specifically intended n Oxley LED bulb replacements provide an for anti-condensation and Sbc’s exclusive from RS for PcI energy” systems with a 1000 vDc fuse. optically designed “fit and forget” alternative to frost protection in control and and PcI Express mini cards A current range from 1 A to 30 A and traditional filament bulbs. They give an excellent equipment cabinets. These a touch safe fuseholder in a compact spread of illumination. and over 90,000 hours n PCI Express Mini Card is a replacement for compact fan heaters prevent 10.3x38 mm package. of operating life. Applications range from push the Mini PCI form factor based on PCI Express. formation of condensation, are online search term: 71247* fuse button switches, mimic panels to rail, automotive, PCI Express Mini Cards are 30 x 56 mm and quiet in operation and provide an evenly distributed interior air military and airborne applications. This true “fit smaller than other add-in card form factors. and forget” product ensures maintenance costs This reduced size permits a higher level of temperature in enclosures with electric/electronic components. are all but eliminated, and the added advantage integration into an embedded PC providing a number of of using LED technology means little or no heat benefits, including Flexibility for Build-To-Order, Upgradeability online search term: Stego, “small fan heater” build up occurs within the equipment. for the newest technology, Seviceability and Reliability. online search term: oxley, “led lamps” online search term: commell, mp* MEMS RANgE fRoM ST MIcRoELEcTRoNIcS LEDIL oPTIcS foR MULITPLE LEDS 3-axis LIS331DL, Low power and tiny package Triple and Quad optics for osram oSLoN SSL Series of LEDs n ST’s 3-axis motion sensors represent a significant step forwardPREcI-DIP SPRINg-LoADED coNNEcToRS in the product’s miniaturization. The LIS331DL n Designed for Osram Oslon SSL series accelerometers deliver high performance at low of LEDs. The lens material is an opticalA perfect alternative for electrical continuity in power consumption and their ultra-compact robust grade PMMA with high UV andproblematic environments. design provides very high immunity to vibration and temperature resistance with a High shock survivability up to 10,000g. optical efficiency of over 85%. Theren Ideal for all mobile communications including medical and online search term: LIS331DL is no need for a lens holder withmilitary applications. Their unique, patented design combinesa contact body, piston and spring to create a self-adjusting fastening; all that’s required to attachcontact. This assures low, stable electrical resistance giving the heatsink is a few droplets of glue.maximum reliability. online search term: ledilonline search term: Preci-dip, Spring Loaded TEKTRoNIx TDS2000c ARDUINo ATMEL PRocESSoR boARDS oScILLoScoPE SERIES Arduino Uno Atmel Atmega 328 McU board Performance at a reasonable price n The Arduino Uno is a microcontroller board based n The TDS2000C Oscilloscope Series provides on the ATmega328. It contains everything needed you with affordable performance in a compact to support the microcontroller; simply connect design. Every model is packed with USB it to a computer with a USb cable, power with connectivity, 16 automated an Ac/Dc adapter or battery to get started. MIcREL bUcK REgULAToRS measurements, limit testing The Uno differs from all preceding boards hyper light load switching regulators and built-in help menu. in that it does not use the fTDI USb-to- Get more done in less serial driver chip. Instead, it features n The MIc23153 is a high efficiency 4Mhz 2A synchronous time with the TDS2000C the Atmega8U2 programmed as a buck regulator with hyperLight Load™ mode, Power good Oscilloscope Series. USb-to-serial converter output indicator, and programmable soft-start. hyperLight online search term: online search term: 715-4081 Load™ provides very high efficiency at light loads and ultra-fast Tektronix, “Digital transient response which makes the MIc23153 perfectly suited oscilloscopes” for supplying processor core voltages. The tiny 2.5mm x 2.5mm package saves precious board space and requires only four small external components. online search term: 711-742310 eTech - ISSUE 5 See more online - over 5,000 new products are added at rswww.com/electronics every month eTech - ISSUE 5 11
  6. 6. ESD Protection Spend a Little – Save a Lot ESD (ElectroStatic Discharge) is a significant threat to quality in the electronics industry. Major companies state that 25% of all unidentified failures of electronic equipment result from damage caused by ESD. In total, ESD-related failures are estimated to cost the industry billions of dollars annually. Investing in a high-quality ESD control plan has been grounded ESD work surface. According to IEC61340- shown to deliver typical ROI from 5:1 up to 20:1 5-1, the electrostatic field at the position where the according to articles in the compliance press. One high- ESDS device is handled must not exceed 10,000V/m. All tech company recently reported equivalent savings of insulators with electrostatic potential greater than 2kV €95 for every €1 spent on ESD protection. must be kept a minimum of 30cm from the device. If the measured electrostatic field or surface potential exceeds An ESD protection plan meeting international standards the stated limits, ionisation or other techniques must be can be implemented using relatively inexpensive used. By generating positive and negative ions, which equipment. To remain effective, it needs to be are attracted or repelled by the charge accumulated on continuously monitored and improved. ElectroStatic the insulator, an air ioniser can neutralise an insulator in charge generation increases significantly as relative a matter of seconds. humidity decreases; so typically if mysterious quality and reliability problems are observed in products The third fundamental principle of the ESD control manufactured during your lowest humidity season, system covers packaging. Shielding bags or it’s likely to be ESD related. containers having a conductive outer surface are commonly used. To be effective, bags and containers Need for a Plan should be closed, and opened only by a grounded Most firms use the EN61340-5-1 standard to construct operator at an ESD workstation. their ESD control plan. The standard addresses grounding and bonding systems, personnel grounding, conclusion protective packaging, and marking. In addition to All ESD control costs should provide the user with setting out a control program plan, EN61340-5-1 improved quality and reliability. To maximize ROI, also describes requirements for ESD training highest loss operations, areas and products should and compliance verification. be identified and addressed first. By keeping ESD Control an on-going quality process, program costs and Specified grounding measures include wrist straps resulting ROI can be monitored so that the company for seated operators, as well as ESD flooring and ESD can maximize total program value. Businesses that get footwear such as foot grounders for standing or mobile ESD right will see a direct and measureable contribution workers. Insulators in the ESD Protected Area (EPA), to their bottom line, as well as an improvement in however, cannot be discharged by grounding. customer satisfaction. EN 61340-5-1 clause 5.3.3 states that “All non-essential insulators (plastics and paper) such as coffee cups, food wrappers and personal items shall be removed from the workstation or any operation where unprotected ESDS items are handled. ” get more online... Process-essential insulators present in the EPA can for more information download the present significant ESD threats such as Field Induced charleswater ESD Awareness booklet Discharges. These can occur even at a properly from www.designspark.com12 eTech - ISSUE 5 eTech - ISSUE 5 13
  7. 7. MAxIMISINg EffIcIENcY fRoM RENEWAbLE ENERgY SoURcES Digital signal controllers can deliver significant efficiency benefits for power inverters in green energy installations. from helga Stevenson The need for alternative forms of power Maximising the efficiency of the PV output is The Maximum Peak Power algorithm is the generation are well established and with a crucial and is typically controlled by the duty most commonly used solution for maximising current focus on renewable sources, solar cycle of the pulse width modulation (PWM) power output, but is inherently variable. panels and wind turbines are receiving signal controlling the DC/DC and/or DC/ Another solution sometimes employed is the considerable attention. As an example, there AC converters. Achieving the most efficient incremental inductance algorithm, which solves are now commercial companies offering free power conversion requires close monitoring the derivative of the voltage/current product panels with installation and maintenance of the power (product of the voltage and (power) curve for 0, which is by definition a contracts for domestic and commercial users, current outputs) from the PV cell. For this a peak. However this method is prone to errors which provide the property owner with power microprocessor is used, along with a number caused by settling on ‘false’ peaks. A more when they need it, while feeding surplus of ADCs. The processor must be capable of elegant solution is to employ a combination of power back in to the national grid. calculating the PWM signal to achieve optimal the two and while this is the most efficient, it conversion conditions, predominantly using a also requires the most processing power. This form of energy generation is, technique known as Maximum Power Point unfortunately, susceptible to inefficiencies. Tracking (MPPT). TI’s TMS320F28x digital signal controller is Photo voltaic (PV) cells offer limited conversion ideally suited to this task; it uses a 32bit device efficiency under the best conditions, but Due to the constantly variable conditions, the that can deliver up to 150 MIPS performance maximising their potential also requires MPPT process is cyclic; it must be performed and integrates a range of peripherals that significant system intelligence, in order to reiteratively to compensate for changes in enable a highly efficient solar panel inverter. provide the best return on investment. output caused by temperature, cloud cover, the Its use has already been reported to have time of day and even seasonal variations. The cut conversion inefficiency by up to 50% in Using complex algorithms, it is possible to objective is to continuously tune the inverters, some installations. achieve high levels of output power even through PWM control, to match the peak under less than ideal conditions and the voltage and peak current outputs of the cell(s). power conversion stage is key in this. This involves measuring and converting the voltage and current outputs and Typically a solar panel installation will use passing their values to the MPPT algorithm, a number of PV cells connected in series calculating the optimal control and feeding and parallel, along with a number of DC/ that back in the form of a PWM control signal. AC inverters to convert the PV output to a While this can be achieved using several mains-rated voltage for use within domestic or discrete devices, a digital signal controller such find the latest TI range of digital signal commercial premises, or to feed back in to the as Texas Instruments’ TMS320C200 family of controllers at rswww.com/ti national grid. Some installations may also use DSP controllers has the right combination of batteries to store energy during good weather peripherals, processing power and architectural conditions, to provide energy during periods of features to perform this complex process in get more online... cloud cover or even through the night. In these real time in a single chip, thereby delivering Share your views on this article installations a number of DC/DC converters will the maximum possible efficiency for a at www.designspark.com/etech also be used. PV installation.14 eTech - ISSUE 5 eTech - ISSUE 5 15
  8. 8. ePurchasing Innovations for Switched-on Supply chain Management by carlene garvey, RS components While bringing tremendous opportunities, Internet shopping also poses a threat to financial control. Many householders have already discovered this fact. businesses, also, need help to make best use of features such as the web’s high speed and vast search powers. Getting it right can help product marketers cut costs and deliver innovations to market more quickly. However, the temptation to exploit potentially dangerous aspects of the web - such as to locate non-approved suppliers offering apparently better prices - can lead to serious problems. Responsible suppliers must recognise these challenges facing their customers and provide innovative online tools, via their websites, that harness the best features of the Internet to provide a trusted source of competitive advantage. harnessing Search Powers An obvious starting place is to enhance product-search capabilities for online customers. For component suppliers, this means providing parametric-search tools to help customers locate components meeting their exact specification. RS Components has built Component Chooser to provide this facility for its customers. Component Chooser is now the world’s largest and most extensive parametric search engine of electronic components. RS Components also provides online Technical Notes, situated at product level, which can provide answers to technical questions and help to inform purchasing decisions. Continued page 18 >16 eTech - ISSUE 5 eTech - ISSUE 5 17
  9. 9. LeCroy WaveAce Oscilloscopes< Continued from page 16 or prices, web-based purchasing tools now tasks that traditionally require a mix of technicalExpanded search capabilities are also valuablefor products such as test equipment as well have the ability to apply these automatically to orders placed by any authorised member of the customer’s staff. Internet shoppers and commercial expertise can simplify product realisation and speed up time to market. Get More Scope for Less Cost –as industry-standard subsystems or modules.Searching the RS website automatically locatescompatible alternatives of suitable quality; everywhere are also familiar with the power of price checking. With just a few clicks, it is easy to locate the best deal in terms of price Looking to Web x.0 As the mobile Internet is now a fast-spreading reality for business communities (as well LeCroy Quality does not come at a high priceexamples include families of RS own-brand alongside other important considerations such as high-end consumer users) thanks toproducts, which are conceived to deliver high as availability, shipping costs and delivery technologies such as 3G and Wi-Fi, smaller andvalue at extremely competitive prices. time. Online price checking is also widely more opportunistic design companies need to used by leading national retailers, and is now manage supply-chain services on the move.For larger companies, in particular, coordinating entering the industrial supply chain in facilities Supporting this trend, RS Mobile is a fully WaveAce combines long memory, a colour Class Leading Specs and Features:aspects such as purchasing decisions, delivery such as RS’ Price Checker price-comparison mobile transactional site that can be viewed display, extensive measurement capabilities, ■ 40 MHz, 60 MHz, 100 MHz, 200 MHz and 300 MHzarrangements and spending by multiple service. The service provides instant visibility on most smart phones.individual users is much tougher in the Internet of equivalent prices from alternative suppliers, advanced triggering and excellent connectivity ■ 2/4 channel modelsage. Emerging generations of intelligent which is frequently updated to help online The arrival of RS Mobile, as a next-generation to improve troubleshooting and shorten ■ Sample rates up to 2 GS/stools can provide the flexibility for individuals customers assess the savings on offer. online tool, reminds us all that the Internet Class leading memory – up to 20 kptsto purchase up to pre-set limits or to work is about change. As opportunities develop, debug time. With bandwidths from 40 MHz to ■ ■ Advanced Triggeringwithin other constraints such as a limited Innovation-to-Market, at Internet Speed the nature of any threats will also change. 300 MHz, sample rates up to 2 GS/s andsupplier list. RS Components’ Purchasing For high-tech companies, whose success Switched-on suppliers have an important role ■ 5.7" colour QVGA display on all models waveform memory up to 20 kpts it exceedsManager is an example of this type of tool. It depends on being the first to market, the to play through continual innovation of their ■ 32 parameter measurementsallows companies to tailor access privileges Internet is opening up numerous opportunities online services to help their customers harness all expectations of a small affordable ■ Waveform Math incl. FFTand available facilities, and so match the at every stage of product realisation. Online the power of the Internet while minimising oscilloscope.purchasing needs of each individual’s role. technical communities sharing information and associated risks. ■ Pass/Fail Testing & Digital FilteringTaking purchasing automation to a higher level, resources such as internet-based tools and ■ Waveform Sequence Recordertools such as eProcurement use web protocols open-source software are just the beginning. ■ Multiple language user-interface and helpto open up communications between There is tremendous scope for web-based ■ LAN/USB connections for printers, memory stickssystems. This is another example of how the design to improve, not only by offeringInternet is improving supply-chain efficiency by more powerful design resources but also by and PC remote controlallowing customers to integrate their internal integrating more efficiently with commercial ■ 3 years warrantyprocurement systems seamlessly with the functions such as purchasing. The DesignSparkRS Components online store. This provides PCB environment available throughinstant access to over 300,000 products, with www.rs-components.com provides WaveAce is the ideal oscilloscope for:live stock availability and the latest pricing an interesting example. ■ Digital design and debuginformation. RS is already expanding this ■ Education and trainingservice with enhancements to features such as DesignSpark PCB is a free-of-charge Windows-the ‘My Account’ area. based EDA tool, created in partnership ■ Manufacturing test and quality control with a third-party specialist EDA vendor, ■ Service and repairPersonalised Automation which engineers can access online. It ■ General bench testIn fact, customer self service, featuring is compatible with industry-standardfacilities for customers to manage their own design-file formats, and hence allowsaccount and even personalise their purchasing engineers to access IP supportedenvironment, is a powerful aspect of internet- by commercial companies as Product Overviewbased commerce throughout the retail as well well as designs availableas trade sectors. Perceived benefits include through open-source WaveAce WaveAce WaveAce WaveAce WaveAce WaveAce WaveAce WaveAce WaveAce WaveAce WaveAce 101 102 112 202 204 212 214 222 224 232 234increased customer satisfaction, reduced hardware communities.instances of errors and misunderstandings, Consistent with its Channels 2 2 2 2 4 2 4 2 4 2 4and lower costs. Enhanced facilities for Internet-based nature, Bandwidth 40 MHz 60 MHz 100 MHz 60 MHz 60 MHz 100 MHz 100 MHz 200 MHz 200 MHz 300 MHz 300 MHztrade customers can include copy invoicing DesignSpark PCB includes Sample Rate 250 MS/s / 250 MS/s / 250 MS/s / 1 GS/s / 1 GS/s / 1 GS/s / 1 GS/s / 1 GS/s / 1 GS/s / 1 GS/s / 1 GS/s /and online quotes, as well as the ability to its users within a dedicated per ch./max. 500 MS/s 500 MS/s 500 MS/s 2 GS/s 2 GS/s 2 GS/s 2 GS/s 2 GS/s 2 GS/s 2 GS/s 2 GS/splace scheduled and forward orders. RS social network providing access Record Length 4 kpts/ch 4 kpts/ch 4 kpts/ch 18 kpts 20 kpts 18 kpts 20 kpts 18 kpts 20 kpts 18 kpts 20 kptsComponents has already implemented these to information in using the tool as well Colour 5.7" 5.7" 5.7" 5.7" 5.7" 5.7" 5.7" 5.7" 5.7" 5.7" 5.7"services online, which help avoid time delays as other aspects of PCB design. Display QVGA QVGA QVGA QVGA QVGA QVGA QVGA QVGA QVGA QVGA QVGAand generally empower customers to improve RS Stock No. 685-2725 672-1589 672-1582 672-1586 685-2734 672-1595 685-2737 672-1598 685-2731 672-1592 685-2740control over their own orders, costs and The important aspect of DesignSpark PCB,administration. In addition, the RS Components from the purchasing perspective, is its abilityStore Manager tool provides complete multi- to export a full bill-of-materials file that canvendor inventory management system, be uploaded directly to the RS Componentshelping customers control spend and online quotation tool to fully cost a prototypemaximise stock efficiency. or manufacturing run of assembled boards and then seamlessly order the necessaryOn top of this, in situations where customers components. Driving this high level of find out more about RS ePurchasinghave negotiated special purchasing terms automation into component engineering solutions at rswww.com/purchasing18 eTech - ISSUE 5 rswww.com/lecroy

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