EEWeb Pulse - Volume 38

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PULSE

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Issue 38 March 20, 2012

Joe Keating

Infinite Power Solutions

Electrical Engineering Community

It’s all about

connections. students hobbyists

discussions

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industry experts

white papers links

resources

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reference designs application notes

lighting

power

community sensor

microcontroller wireless

The user-to-user forum is for everyone, from design engineers to hobbyists, to discuss technology, products, designs and more.

Join the discussions that match your interest or offer your expertise to others.

Join the discussion now at:

www.digikey.com/techxchange Digi-Key is an authorized distributor for all supplier partners. New products added daily. Š 2011 Digi-Key Corporation, 701 Brooks Ave. South, Thief River Falls, MN 56701, USA

TA B L E O F C O N T E N T S TABLE OF CONTENTS

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Joe Keating Infinite Power Solutions Interview with Joe Keating - Senior Director of Applications Engineering

10

Self-Powered Maintenance-Free Sensor Node for Smart Phones

BY JOE KEATING Infinite Power Solutions Targets Bluetooth Smart Devices Using THINERGY MECs.

12

Featured Products Timing the Communication Channels of an Encoder to a Brushless Motor

14

BY JIM MILLER WITH QUANTUM DEVICES, INC. Timing is everything--from a car engine to an optical encoder.

The Aquarius MRE System: A Marine Renewable Energy Solution for Modern Ships

17

BY GREG ATKINSON WITH ECO MARINE POWER How past and present energy technologies are integrated for a “greener” power solution.

RTZ - Return to Zero Comic

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INTERVIEW

Infinite Power Solutions Joe Keating - Senior Director of Applications Engineering

How did you get into electrical engineering and when did you start?

I graduated with a degree in Electrical and Computer Engineering in 1992 and have been working in and around the field of electronics ever since.

Can you tell us about your work experience before becoming a Senior Director of Applications Engineering at Infinite Power Solutions?

I have a diverse background in consumer, industrial and commercial product development. I have also spent quite a bit of my career working on battery development, battery applications, and testing.

Who has influenced you the most throughout your career?

I have benefited from many mentors throughout my career. They have mostly been peers who have exhibited talents and interest in their respective fields, leading them to produce successful designs, products and solutions.

By working with them and observing their design and development methods, I have been able to build core design and development skills that have been valuable across a range of different markets and industries. I have also benefitted from many opportunities to work

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FEATURED INTERVIEW

Joe Keating

INTERVIEW

What are your favorite hardware tools that you use?

I always start with a trusty Fluke meter, preferably a model 87 or newer. Microchip and TI, among others, have traditionally produced excellent low-cost embedded development tools that include circuit emulation, which I think is critical in any efficient embedded system development flow. Any ICE tool is usually a great thing to have. Also, an oscilloscope, power supply, soldering iron and a link to the Digi-Key site are all essential tools.

How about your favorite software tools?

I’m a huge fan of Altium. We converted to their tools last year and haven’t looked back. For a small to mid-sized electronics design and development firm, it’s my top pick for PCB schematic capture and layout. I also always have a copy of 5SPICE ready to go.

What is on your bookshelf?

The Art of Electronics by Horowitz and Hill, Modular Series on Solid State Devices, Volumes 1-4, RF Design Guide by Vizmuller, Numerical Methods for Engineers

by Chapra and Canale, and a plethora of battery books.

Do you have any tricks up your sleeve?

Don’t underestimate the design

and testing time required when developing a battery-powered system for a product. Batteries, in my experience, are akin to living things and have many caveats and quirks that require careful consideration before being included in a design.

A good rule of thumb, especially when working with a rechargeable battery, is to get in touch with the technical support team of the selected battery manufacturer as early as possible in the design process. This can eliminate several board spins and will help to get your product out in time.

What has been your favorite project so far?

I developed a multichannel battery cycle testing system for an extremely high-power lead acid battery that we were bringing to market. We produced a cell that could be built into a 1kg battery pack that could fit in your hand and was capable of cold starting a Corvette. The testing system required development from the board level through to the company-wide network in order to provide real time testing data to our R&D and manufacturing teams.

Do you have any noteworthy engineering experiences?

I have a few patents and have been asked to present at various conferences and panels. I’ve been fortunate to have participated in an IPO event for a start-up company in which I was the fourth employee.

Do you have any experiential stories you would like to share?

I did have a close call when working on a hybrid battery I designed for a

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prototype HEV being tested by one of the “big three” in Detroit back in the 90s. We were doing acceleration runs to test the peak power output of the combined system. As the battery engineer, I was asked to participate in the testing. The test vehicle was based on a mini-van. The two primary engineers were in the front seats with full crash harnesses. The components for the HEV took up the passenger area, so I was sitting on a foam block between the two front seats, holding a laptop that was collecting data from the test runs.

We were zipping up and down an access road behind the engineering facility that was also used by trucks to bring in inventory to a nearby Home Depot. We were focused on the laptop screen when I looked up and saw the word “PETERBILT” coming straight at me. Fortunately, the engineer driving the van had pretty good reflexes and swerved out of the way of the oncoming tractor trailer in time to keep me from becoming a hood ornament.

How do you provide application support and development for new, innovative, thin film Lithium battery technology?

As I noted above, we try to get the applications team involved at the beginning of the engagement with every customer. Batteries are a technical sale and require close and thorough support in order to make sure that the product is successful.

Because we have been working in this space for many years, our applications engineers have many tricks and design insights available to ensure that the electronics or application requirements are served by the proper battery and

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FEATURED INTERVIEW

in fields that are well outside of the traditional electronics designer’s duties, such as manufacturing management, quality systems development, and direct sales and marketing activities.

INTERVIEW

Can you tell us about your industry experience in consumer electronics, battery design and manufacturing, textile equipment and optics?

I guess the thing I’m most aware of after working across a diverse set of industries is that it is important to keep an eye on the bigger picture involving the customer.

A strategy of providing solutions that meet customer requirements should override most if not all other concerns within the development process. Driving the strategy requires a strong, clear and focused vision regarding the product or service that is being provided.

I have seen too many products limp into production because the goals weren’t clear. This resulted in solutions that cost the company too much to produce and support.

Commitment to setting up and adhering to specific product feature and quality targets is paramount to succeeding in any industrial or technology market. Strong engineering leadership committed to this process always yields positive results when the products hit the market.

What are some of the new technologies you are working on at Infinite Power Solutions?

IPS is the world leader in developing thin film, solid state rechargeable batteries. We are also involved in the development of new power source technologies for microelectronics, specifically in the areas of wireless sensors, real-time clocks/memory backup and powered cards.

Wireless sensors are undergoing a revolution in that they are becoming the keystone technology in an increasingly sensor-aware world.

To date, the major stumbling block for wireless sensors has been the

IPS is very customer focused with a dedicated and highly experienced applications engineering team to help our customers plan their design and properly implement our battery into their system. battery.

Primary (or nonrechargeable) batteries have traditionally been used as the power source for wireless sensors, such as remote temperature or security

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sensors found in buildings. This has greatly limited the adoption of these technologies because the cost required to change the batteries in a given facility will become onerous as the number of sensors increases.

In addition, dead batteries imply that the sensor will no longer function properly. Rechargeable solutions such as Lithium Ion or Lithium Polymer batteries do not have sufficient cycle life or longevity to provide power to sensor systems for the required minimum functional life of most commercial or industrial sensors. This results in maintenance costs that often make wireless sensors impractical.

THINERGY® Micro-Energy Cells (MECs) from Infinite Power Solutions (IPS) solve this problem by providing an operational lifetime in excess of 15 years, and cycling performance that is 10–100 times better than most other rechargeable battery technologies. As a result, we can combine our MECs with energy-harvesting devices such as solar panels, thermoelectric generators, piezoelectric devices or RF-harvesting systems to provide a power source that will gather and store ambient energy from the environment surrounding the sensor. This allows the sensor to operate for decades without any maintenance or power failure events. IPS has developed technology around this concept that includes some of the world’s lowest power sensor or wireless node solutions. We have collaborated in the development of several new ultra-low power energy storage and management IC solutions such as the MAX17710 from Maxim Integrated Products, the LTC4071 from Linear Technologies and the

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FEATURED INTERVIEW

power management solution.

Additionally, we have accumulated world-leading experience in the development of self-sustaining or autonomously powered microelectronic solutions. To support this, we have created a team of engineers and technicians that can provide any level of technical support from documentation to entire product design depending on a given customer’s needs.

INTERVIEW

Can you tell us more about Infinite Power Solutions?

IPS is a clean technology growth firm that manufactures its solidstate energy storage products in a custom-built facility in Littleton, Colorado. IPS is a small but growing R&D and manufacturing company that leads the industry in bringing the world’s thinnest, most powerful and longest-lasting batteries to the micro-power market. By providing solutions into a region within the energy storage market where there have not previously been suitable solutions, IPS will enable potentially massive new markets and products to be developed.

How does Infinite Power Solutions continue to be a global leader in manufacturing solid-state, rechargeable, thin-film microenergy storage devices for embedded applications?

IPS continues to maintain its solidstate battery industry leadership in a variety of ways. First and foremost,

THINERGY MECs outperform competing small battery solutions in all performance metrics, especially when it comes to operating temperature range, discharge rate and cycle life. IPS also has a formidable intellectual property portfolio with numerous granted U.S. and international patents that are vital to the manufacture of solidstate thin-film batteries. Continued Research and Development has also been a key differentiator for IPS as it continues to develop advanced packaging and manufacturing methodologies, as well as developing new solid-state battery solutions with unprecedented energy density.

...IPS will introduce new, low-cost rechargeable battery solutions with industry leading energy density that will displace a variety of common battery types in use today.

How has the company changed since its founding in 2001?

In the early days, IPS fabricated its thin-film batteries on a thin ceramic substrate, much like those developed at Oak Ridge National

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Labs. While ceramic is an ideal surface for depositing thin-films and for proving the virtues of solidstate battery performance, it was not ideal in terms of material cost or for end users who wanted a thinner, more flexible solution. In 2007, IPS began to fabricate cells on thin (50Âľm) metal foil substrates and quickly became the envy of the solid-sate battery industry.

No other manufacturer has been successful fabricating such cells on this low-cost metal foil substrate which provides advantages in hightemperature processing during fabrication, in addition to thinness, flexibility, hermeticity, and overall simplicity.

What is the work culture like at Infinite Power Solutions?

IPS is very customer-focused with a dedicated and highly experienced applications engineering team to help our customers plan their design and properly implement our battery into their system.

What direction do you see your business heading in the next few years?

IPS continues to lead the small rechargeable battery industry in all performance metrics. Over the next few years, IPS will introduce new, low-cost rechargeable battery solutions with industry leading energy density that will displace a variety of common battery types in use today.

What challenges do you foresee in our industry?

Well, it’s hard to see into the future, but generally speaking, adoption of new or improved technologies

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FEATURED INTERVIEW

BQ25504 from Texas Instruments.

These parts all provide simple and ultra-efficient energy storage management solutions, enabling designers to combine an energy harvesting device such as a small solar panel with a THINERGY MEC to power an RF-based sensor node enabling a network of small, maintenance free, robust sensors.

This revolution in remote power delivery will vastly increase the deployment of wireless sensors allowing buildings to operate more efficiently, machinery to become more reliable and facilities to become more secure, just to name a few applications.

INTERVIEW many different standards options in our target markets that cause confusion and increase the risk for our end customers as they attempt to bring solutions to their customers.

What are some of your hobbies outside of work and design?

I ski, mountain bike and race motorcycles. It’s Colorado, so there’s a lot to do with the 300+ days of sunshine we get!

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Is there anything that you have not accomplished yet, that you have your sights on accomplishing in the near future?

One of these days I hope to start up a new company, but for now I’m focused on getting IPS and our very exciting solid-state battery technologies out to the mass market! ■

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FEATURED INTERVIEW

is often hampered by the slow or conflicting development of standards. This will be a continuing effort for IPS to work with the various players within the wireless sensor and powered card markets to attempt to unify or condense the many proposed and existing standards that are available today.

As certain manufacturers begin to dominate in these markets, their selected standards will gain acceptance across a wider audience. At this time, there are

Avago Technologies Optocoupler Solutions

2 Times Faster, 50% Smaller, True Rail-to-Rail Output Voltage IGBT Gate Drives Applications Avago Technologies, an industry leader

in IGBT Gate Drive technology solutions IGBT/MOSFET Gate Drive introduces our Next Generation series!

AC and Brushless Based on BCDMOS technology Avago can DC Motor Drives deliver higher peak output current, better railRenewable Energy Inverters Industrial Inverters Switching Power Supplies

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The increased drive and speed along with the very high CMR (common mode rejection) and isolation voltage will enable you to build more efficient and reliable motor drive and power conversion systems. In addition the SO6 package which is up to 50% smaller than conventional DIP packages facilitates smaller more compact design.

Benefits • Suitable for wide range of IGBT class for different market applications • High output peak current for fast and efficient IGBT operation • Rail-to-rail output voltage for reliable IGBT operation • Lower system power budget • Suitable for bootstrap power supply operation • Reduce dead time and improve system efficiency • Prevent erroneous driving of IGBT in noisy environment • 40%-50% smaller than DIP package for space and cost savings To request a free evaluation board go to:

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PROJECT

Infinite Power Solutions Targets Bluetooth Smart Devices Using THINERGY MECs

By Joe Keating

With the introduction of the new Bluetooth 4.0 standard that will soon be available in many portable devices such as phones and tablets, comes a sub-feature known as Bluetooth Low Energy (BLE).

Traditional Bluetooth® devices such as headsets draw a fairly high amount of continuous current requiring rechargeable Lithium Polymer (LiPO) batteries that provide sufficient energy and power in order to maintain voice or data streaming. However, for low power, intermittent applications such as temperature sensors, maintaining a Bluetooth session tends to require a great deal more energy than is really necessary to support low data rate transmissions. BLE, on the other hand, can produce thousands to millions of short, low data rate wireless transactions using the energy from a single charge provided by a much smaller

battery. Devices incorporating this low power BLE feature are known as “Bluetooth Smart” devices.

The power consumption rates are actually so low that extremely small batteries can be used to power tiny, ultra-low power Bluetooth Smart sensors that will communicate with phones and phone-based apps while being constantly recharged with energy scavenged from the surrounding environment (think small solar panels, etc.). My company, Infinite Power Solutions (IPS), offers 4V solid-state batteries known as THINERGY® MicroEnergy Cells (MECs) that are particularly well-suited for Bluetooth Low Energy applications. To address this emerging market, IPS is working on a BLE based sensor reference design.

By introducing this technology into our handheld devices, low power sensors can now be ubiquitous in

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FEATURED PROJECT

Self-Powered Maintenance-Free Sensor Node for Smart Phones

our personal environments and will be able to communicate through our phones, for example, to our friends, families, doctors, etc., to provide information such as security access, activity, temperature or blood pressure. The downside of adding wireless sensors everywhere has traditionally been the need to replace batteries. Imagine being trapped in a sea of devices that constantly clamor for battery replacement (anyone with children can sympathize!). This is especially problematic for biometric sensors that could be installed to monitor health and activity statistics for people under constant care. It will be difficult to require Alzheimer’s patients, for example, to change batteries on their temperature or activity sensors. Fortunately, the BLE specification power requirements are so low that for short transactions such as communicating your proximity to your desk (useful for granting secure access to a work station), an MEC can be maintained in a full state of charge indefinitely by harvesting microwatts from a small solar panel installed on the sensor.

THINERGY solid-state MECs are a great fit for this model in that they have the ability to efficiently store energy down to power levels below 1µW and last for more than 15 years because of their extremely low internal leakage rates and lack of liquids or polymers. As a result, the design of the sensor will be radically changed. An over-mold or potted enclosure can now be used since the battery won’t wear out for the lifetime of the product and will never need to be changed. This eliminates the need for the typical “clamshell” style enclosure with a battery door and separate battery

PROJECT

Figure 1: BLE Transaction Current levelsi

Figure 2: Functional Block Diagram

contacts. Assembly steps are eliminated along with a great deal of material reducing cost. This results in a very durable, fully enclosed sensor module that will last for years without any user maintenance.

Since the unit will be constantly charging from the embedded solar panel, no further user intervention is required.

As with all battery powered designs, the power requirements need to be addressed to figure out how large the MEC and the solar panel will have to be in order to

meet the user’s requirements. In this case, our reference design will be transmitting proximity using RSSI (received signal strength indication, a feature included in the BLE specification) along with temperature transmission once every five seconds. The following image from Texas Instruments shows the measured current used during a single BLE transaction using a TI CC2540 BLE SOC. The scope settings used were 60mV per division with the time scale at 400µs per division. A 10Ω

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The result will be a simple, maintenance-free Bluetooth Smart sensor that will directly communicate with an iPhone (the iPhone 4S is the first phone with BLE). A simple app developed for the phone will allow users to view or share information from their environment to the web or to other services, games or social networks, opening up a whole new world of interactive applications.

“Application Note AN092: Measuring Bluetooth Low Energy Power Consumption”, Sandeep Kamath, Texas Insturments, 2010 ■ i

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FEATURED PROJECT

resistor was used in line with the power source to measure the current. By integrating the area under the curve, the result is 24.5µAs for this single transaction, which is the equivalent of 10.6mA average current over a 2.3ms period. Assuming that we are using a 130µAh THINERGY MEC225, which is 0.17mm x 1.6cm^2, more than 19,000 transactions can be made on a single charge. Of course this doesn’t take into account the sleep current between sessions.

Assuming that this sleep current is 0.5µA or so, which is easily attainable with today’s real-time clocks and microcontrollers, you can then calculate the average current to be approximately 6µA, which results in 24 hours of operating time on a single charge.

This also implies that an average of 6µA needs to be supplied to the unit from a solar panel to keep the battery from running out. Getting this amount of current is extremely easy using even a very small and inexpensive solar panel.

F E AT U R E D P R O D U C T S Highlighting its role as a leader in ARM®-based embedded processing, Freescale Semiconductor (NYSE: FSL) announced it will demonstrate its new Kinetis L series microcontrollers (MCUs) built on the ARM® Cortex™-M0+ processor at DESIGN West in San Jose, California. Alpha sampling of Kinetis L series devices will begin in the second quarter of 2012. Freescale’s early demonstration of Kinetis L series devices is possible due to the close partnership between Freescale and ARM during the Cortex-M0+ core development process. Freescale was a lead partner, providing input that helped ARM define and develop the world’s most energy-efficient processor, designed to satisfy the rigorous energy-efficiency, cost-sensitivity and ease-of-use requirements of entrylevel applications suFor more information, please click here.

24-bit ADCs with Built-In PGA & Reference

REF

The ADS1291, ADS1292, and ADS1292R are multichannel, simultaneous sampling, 24-bit, delta-sigma (ΔΣ) analog-to-digital converters (ADCs) with a built-in programmable gain amplifier (PGA), internal reference, and an onboard oscillator. The ADS1291, ADS1292, and ADS1292R incorporate all features commonly required in portable, low-power medical electrocardiogram (ECG), sports, and fitness applications.

With high levels of integration and exceptional performance, the ADS1291, ADS1292, and ADS1292R enable the creation of scalable medical instrumentation systems at significantly reduced size, power, and overall cost. The ADS1291, ADS1292, and ADS1292R have a flexible input multiplexer per channel that can be independently connected to the internally-generated signals for test, temperature, and lead-off detection. For more information, please click here.

Monitors

Reference

SPI

SPI

(ADS1292R)

IN P U T S

RESP DEMOD

C LK

A1

ADC1

Oscillator

MUX

Control

A2

ADC2

(ADS1292R) RESP MOD

RESP

RLD

Atmel AVR® MCU family Expanded Atmel® Corporation, a leader in microcontroller and touch technology solutions, announced 14 new devices in its widely adopted Atmel AVR® microcontroller (MCU) family, providing more options to meet unique design requirements. Used by well over 100,000 engineers worldwide, AVR microcontrollers are regarded for their performance, power efficiency and flexibility across many application areas. Adding more memory, connectivity peripherals and system integration, the newest devices further extend the advantages of the AVR family, while supporting a broader array of application areas including consumer electronics, capacitive touch, utility metering, home automation and medical. These AVR MCUs meet a common demand across multiple application areas: low power consumption. All devices in the portfolio are designed for the lowest possible power consumption using Atmel picoPower® technology, operating down to 1.62V while maintaining all functionality and short wake-up times.

The AVR MCU portfolio also includes devices that support Atmel QTouch® Library for capacitive touch functions.

For more information, please click here.

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FEATURED PRODUCTS

ARM® Cortex-M0+ Microcontrollers

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Timing the Commutation Channels of an

Optical Encoder

to a

Brushless Motor

Jim Miller

Application/design Engineer

A

lignment of optical encoder commutation signals to a Brushless DC (BLDC) motor could be thought of as being comparable to timing the distributor on a car engine — the distributor tells the spark plugs on the engine when to fire. In a similar manner, the commutation channels of an incremental encoder tell the amplifier or drive when to turn on the windings in a BLDC motor.

Basic Steps:

And just like a car engine, if the timing is off, the motor will run incorrectly, inefficiently, or not at all. If two of the encoder commutation phases are accidentally reversed, the motor will run backwards.

3. The encoder is assembled to the motor and the shaft is locked in place (via encoder set screws). The encoder flex mount is not yet secured.

To time commutation channels of an incremental encoder to a BLDC motor, you will need to know which motor winding corresponds to which encoder commutation signal. This information is usually found in the motor and encoder documentation.

As I am most intimately familiar with the Quantum Devices series of encoders, the following steps are best suited to those encoders, but should serve as a general guide to timing any encoder.

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1. One phase of the motor is energized, locking the rotor into position.

2. The encoder is rotated to a given position, which is usually the start of one of the commutation signals (i.e., leading edge of U). This often corresponds with the encoder’s index pulse.

4. The motor winding is de-energized.

5. The Optical Encoder is powered.

6. The motor/encoder is back driven by another motor and the two waveforms are displayed on an oscilloscope. One waveform is back EMF from the motor phase, and the other is the encoder commutation channel.

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TECHNICAL ARTICLE

8. Once alignment is achieved, the encoder flex mount is secured, locking in the phase relationship between the motor and encoder.

About the Author Figure 1: Back driven motor set up

Below the motor, back EMF and Encoder Commutation (Hall) signals are shown. They have been separated for clarity, when timing a motor,they will overlap.

Jim Miller is employed with Quantum Devices Inc, a leading manufacturer of optical rotary incremental encoders. He plays a vital role in optical encoder design and development. â–

Figure 2

7. While the motor is rotating, the assembly is fine-tuned by turning the encoder body to align the encoder signal to the motor’s back EMF waveform.

Video of BLDC motor Back EMF to Optical Encoder Commutation Timing.

Figure 3

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TECHNICAL ARTICLE

Proper timing typically calls for aligning the zero volt level of the back EMF sine wave with the edges of the commutation signals. That level is shown in Figure 3 by the red line.

Get the Datasheet and Order Samples http://www.intersil.com

3A, Rad Hard, Positive, Ultra Low Dropout Regulator ISL75051SRH

Features

The ISL75051SRH is a radiation hardened low-voltage, high-current, single-output LDO specified for up to 3.0A of continuous output current. These devices operate over an input voltage range of 2.2V to 6.0V and are capable of providing output voltages of 0.8V to 5.0V adjustable based on resistor divider setting. Dropout voltages as low as 65mV can be realized using the device.

• DLA SMD#5962-11212

The OCP pin allows the short circuit output current limit threshold to be programmed by means of a resistor from the OCP pin to GND. The OCP setting range is from 0.5A minimum to 8.5A maximum. The resistor sets the constant current threshold for the output under fault conditions. The thermal shutdown disables the output if the device temperature exceeds the specified value. It subsequently enters an ON/OFF cycle until the fault is removed. The ENABLE feature allows the part to be placed into a low current shutdown mode that typically draws about 1µA. When enabled, the device operates with a typical low ground current of 11mA, which provides for operation with low quiescent power consumption.

The device is optimized for fast transient response and single event effects. This reduces the magnitude of SET seen on the output. Additional protection diodes and filters are not needed.

The device is stable with tantalum capacitors as low as 47µF and provides excellent regulation all the way from no load to full load. Programmable soft-start allows the user to program the inrush current by means of the decoupling capacitor value used on the BYP pin.

Applications

• Output Current Up to 3.0A at TJ = 150°C • Output Accuracy ±1.5% over MIL Temp Range • Ultra Low Dropout: - 65mV Typ Dropout at 1.0A - 225mV Typ Dropout at 3.0A • Noise of 100µVRMS from 300Hz to 300kHz • SET Mitigation with No Added Filtering/Diodes • Input Supply Range: 2.2V to 6.0V • Fast Load Transient Response • Shutdown Current of 1µA Typ • Output Adjustable Using External Resistors • PSRR 66dB Typ @ 1kHz • Enable and PGood Feature • Programmable Soft-start/Inrush Current Limiting • Adjustable Overcurrent Limit from 0.5A to 8.5A • Over-temperature Shutdown • Stable with 47µF Min Tantalum Capacitor • 18 Ld Ceramic Flatpack Package • Radiation Environment - High Dose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 krad(Si) - SET/SEL/SEB . . . . . . . . . . . . . . . . . . . . . . . .86 MeV•cm2/mg

• LDO Regulator for Space Application • DSP, FPGA and µP Core Power Supplies • Post-regulation of Switched Mode Power Supplies • Down-hole Drilling

0.30 ROCP

EN

BYP

OCP

ADJ

ISL75051SRH

VIN

220uF

0.1uF VOUT

VIN

VOUT

PG

GND

R1 0.1uF

0.1uF 2.67k

VIN

4.7n PG

R2 100pF

FIGURE 1. TYPICAL APPLICATION

November 4, 2011 FN7610.1

220uF

DROPOUT VOLTAGE (V)

EN

+150°C

0.25

+125°C

0.20 0.15

+25°C

0.10 0.05 0.00 0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

IOUT (A)

FIGURE 2. DROPOUT vs IOUT

Intersil (and design) is a registered trademark of Intersil Americas Inc. Copyright Intersil Americas Inc. 2011 All Rights Reserved. All other trademarks mentioned are the property of their respective owners.

The Aquarius MRE System: A Marine Renewable Energy Solution for Modern Ships Greg Atkinson

Director, Research & Development

Wind & Solar Power at Sea Wind power has been used by ships as a means of propulsion for thousands of years, but with the advent of the steam and internal combustion engines during the Industrial Revolution, the use of sail power fell away sharply around the mid-19th century. Today however, there is a resurgent interest in the use of sails for commercial vessels as shipping companies seek ways to reduce fuel costs and comply with new airborne maritime mission standards.

Traditional flexible sails with rigging are generally not suitable for large commercial ships, however rigid sails could be a practical way to utilize wind power on modern ocean-going vessels in order to

lower fuel consumption & reduce noxious gas emissions.

Rigid sails are not a new concept and designs vary widely. In the 1970s and 1980s, for example, two ships in Japan were fitted with curved rigid sails, and in the 1980s Jacques Cousteau, Professor Lucien Malavard and Dr. Bertrand Charrier developed a turbosail which was then fitted to the research ship, Alcyone.

Both of these innovative concepts reduced fuel consumption, however, for a variety of reasons, rigid sails have not yet gained widespread acceptance.

Solar power is another renewable energy technology also suitable for ships. In recent years, significant advances have been

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made in terms of developing solar panels that are lightweight, more efficient and suitable for the harsh marine environment. A number of commercial ocean-going ships have already been fitted with solar panels such as Nippon Yusen’s (NYK) Auriga Leader.

At this stage, solar power alone is unable to provide the energy required for propulsion on large ships. It can, however, be an important alternative source of power for on-board electrical systems, thereby helping to reduce fuel consumption and noxious gas emissions.

The challenge for system designers is to develop a solution for ships that can tap into the power of the wind and sun, yet be cost effective,

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A Combined Wind & Solar Power Solution for Ships Unlike land-based renewable energy solutions such as solar and wind farms, the area or space available on ships for installing wind and solar power systems is quite limited. Taking this into account, it would appear advantageous to develop a system that can use both wind and solar power as energy sources, and be able to harness it via the same system.

The Aquarius Marine Renewable Energy (MRE) System being developed by Eco Marine Power will achieve this by using rigid sails and an array of solar panels.

The Aquarius MRE System™ (patent pending) or Aquarius System™ will use this array of rigid sails and solar panels to form a ship-based renewable energy system. On large

ships, up to twenty rigid sails could be installed whereas on smaller vessels, just one or two sails would be needed.

The Aquarius MRE System™ is not intended to be a ship’s primary source of propulsion. Instead, the system is being designed to work alongside other technologies to reduce fuel consumption and harmful gas emissions for a variety of ships such as bulk carriers, oil tankers and cargo ships.

Depending on the number, size, shape and configuration of the rigid sails, it is estimated that the system will reduce a vessel’s annual fuel consumption by up to 20 percent.

Aquarius MRE System™ Technology Large commercial ships such as bulk carriers and oil tankers operate with a small crew, therefore a renewable energy solution for these types of vessels needs to be

automated.

To achieve this, an advanced computer control system is being developed so that the rigid sails will automatically be positioned to adapt to the prevailing weather conditions.

The rigid sails can be rotated to best use the available wind, or if there is no wind, then the solar panels or cells will be able to collect solar energy during the day. The solar panels could be mounted on the sails, or alternatively, they could be mounted elsewhere on the ship.

In addition, the control system will monitor the performance of the system and provide a means by which the crew can manually control the rigid sails if needed via command consoles. These consoles can be located in a variety of positions on-board the ship.

The computer control system will also include a number of safety features to prevent the sails or ship from being damaged.

The Aquarius computer control system will be based on the KEI 3240 Computer System developed

by KEI System Ltd. of Osaka, Japan.

The KEI 3240 Computer System is a highly reliable, marine type approved system that is already in use today. The main computer unit is able to operate in temperatures ranging from 5°C to 55°C and the local I/O units are able to operate between 5°C to 70°C. This robustness makes it ideal for shipborne applications.

Figure 1: Impression of the Aquarius MRE SystemTM on an Oil Tanker

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Each rigid sail will be physically raised, lowered and maneuvered by a positional system which will

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practical and safe for the crew or vessel.

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Most importantly, the positional system will be able to store the rigid sails in a protective housing so they are not damaged during storms or do not interfere with cargo loading/ unloading operations.

Another important feature of the Aquarius MRE System™ is that it incorporates an advanced energy storage system based on Lithium Ion technology from Corvus Energy Ltd. of Vancouver, Canada.

Corvus Energy’s advanced lithiumpolymer battery technology will store energy collected by the solar panels or it can be used to store power from the ship’s generators.

The batteries will then help power the ship’s electrical equipment or be utilized as a power source when the ship is in harbor or at anchor.

Using power from the batteries will also satisfy the growing demand at ports to reduce greenhouse gas (GHG) emissions and particulate matter.

Additionally, the power stored in the battery modules could be used as a highly reliable back-up power source.

Each AT6500 series battery module from Corvus Energy has the ability to be combined to form a custom sized pack—from 6.5 kWh to multi-megawatt applications. The modules can be configured in any number of ways to build the size

of the required battery pack, and will allow for the energy storage component of the Aquarius MRE System™ to be highly flexible.

overlooked, but will play a critical role in terms of making renewable energy a viable source of energy on-board the ships of the future.

The AT6500 modules are also inherently safe and capable of being used in the most demanding environments as the modules and the connectors are fully sealed.

For more information about the various development projects at Eco Marine Power (EMP), please click here.

Further important features of the battery modules are that they are 99 percent recyclable, lightweight and require no ongoing maintenance.

At this stage, there are plans to incorporate CIS solar module technology into the Aquarius System™ because of its performance, plus it also complies with European RoHS (Restriction of Hazardous Substances) regulations. However, other solar cell technologies are being studied and may also be used.

On a large bulk ore carrier, the total installed solar power could be 500 kWp or more. But as the cost of solar panels decreases and their efficiency increases, it may become feasible to expand the capacity of the installed solar power toward 1 MWp.

About the Author Greg Atkinson is a technology professional with over 25 years experience that includes service in the Royal Australian Navy and holding a range of positions in the telecommunications sector such as network operations, network support, project management and product development. He holds an MBA, a B.Sc in Electrical Engineering, an Associate Diploma in Electronic Systems Maintenance and is a Member of the Australian Institute of Company Directors.

(MAICD). Greg is currently based in Fukuoka, Japan, where he is leading various design projects at Eco Marine Power. ■

Future Developments The large-scale use of modern renewable energy technology on ships is still in its infancy. As various technologies develop in the years ahead, we are likely to see the adoption of wind and solar power solutions in a variety of forms become widespread across the shipping sector.

The control, energy storage and power management systems for these solutions are sometimes

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interface with the computer control system. The rigid sails will be able to move as an array or individually, either automatically as directed by the computer control system or via manual commands entered by the crew on the control console(s).

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