Electro-ramblings

Spelling out solar cell stories

2008-07-04T07:18:12Z

An alternative guide to solar cell technology.

A - Z of Solar Cells
A	Abu Dhabi billions
B	Braggone captures light
C	CIGS cells
D	Drag racing
E	Electrical energy
F	Flexible power
G	Generational substrates
H	HSBC
I	IMEC
I	iPod power
J	Junctions
K	Kyocera high-efficiency
L	Lighting uses
M	Mobile phone panels
N	NETPark, Co. Durham
O	OLED research
P	Plastics gov funding
Q	Qimonda joint venture
R	Recycling wafers
S	SpectaWatt
T	Thin film
U	University of Cambridge
V	Video solar cell racing
W	Wafer deal
X	ISC x VOC
Z	Zephyr plane
Spelling out solar cell stories

An Engineer in Wonderland - Waterwheels

2008-07-03T07:12:55Z

I have always had a soft spot for waterwheels, but like many things historic, thought they were all much of a muchness.

But Windmills and Waterwheels Explained by Stan Yorke has changed all that for me.

So fascinating I find difficult to put down, it has taught me that there were innovations in waterwheel design throughout their history.

For example, for thousands of years the central axle of water wheels carried power into the mill building.

Then some bright spark realised that you can bolt a great big gear to the wheel, and mesh it with a little gear to take power into the building.

The new drive shaft runs faster - so less gearing up is needed inside - and can be thinner because it is transmitting less torque.

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There is also the cunning paddle arrangement of French physicist Poncelet.

He took a huge step away from any-flat-plank-will-do paddles and introduced a brestshot wheel with a curved blade/bucket design that took almost all of the kinetic energy out of the water that struck it.

I rate this alongside the Pelton wheel - a high-pressure high-speed water wheel invented in California in Victorian times.

The spoon-shaped blades of Pelton's design cunningly reverse the flow of impinging water. Once the wheel is moving at its design velocity, water exits the blades stationary, having given up over 90 per cent of its energy to the shaft.

On a cycling trip in California, I was lucky enough to come across one of the first Pelton wheels, a huge one in Grass Valley, which is where I learned that they were invented in the region.

'Alice' alice@electronicsweekly.com

See also:

http://www.strollingguides.co.uk/workshop/darkroom/galleries/
http://www.wheal-martyn.com/historical.html

(Picture - 'Gear2_Big Otter Mill_1#9B4F' by ellievanhoutte, under the Creative Commons Attribution licence)

Don't forget to sign up to the Electronics Weekly newsletters

2008-07-03T07:01:55Z

It's my periodic reminder: Have you signed up to receive the Circuits or Made by Monkeys newsletters yet? Or the general, weekly Electronics Weekly newsletter, bringing you the latest news and content from the site?

Go to MyAccount to make sure you keep receiving them. If you wish to receive the newsletters you will need to register!

Also, there is a new entry in the stable - a newsletter supporting the Mannerisms blog and its analysis and comment on the semiconductor industry. It is just about to launch, with the first mailing this Tuesday.

]]> * The Mannerisms eNewsletter provides entertaining and authoritative commentary on the semiconductor industry [weekly]

* Our Circuits eNewsletter is chock full of ideas for design engineers who love circuits and are looking for inspiration for their own projects. [fortnightly]

* Made by Monkeys provides analysis and commentary on cheaply-made and underperforming products, and tips for achieving better designs. [fortnightly]

* The weekly editorial newsletter highlights the latest Products, Jobs and news featured on the site, along with in-depth articles and the most popular site content. [weekly]

Make sure to sign up to keep receiving the latest Circuits and a multitude of design ideas delivered directly to your inbox! Login and edit your profile.

Use analogue switches to multiplex your signals

2008-07-02T11:40:28Z

Check out another recent feature added to our site: Use analogue switches to multiplex your signals

Written by Paul Rako, Technical Editor of our sister site EDN, it looks at the myriad applications and multifaceted specifications of analogue switches, showing that there is more than meets the eye with these ubiquitous little parts.

He begins:

Few IC-schematic symbols are simpler than the one that depicts an analogue switch (Figure 1a). A basic switch comprises just an input, an output, a control pin, and a couple of power-supply pins. Yet, bedazzling complexity hides behind this simple appearance (Figure 1b).

]]> Several specifications, including power-supply voltage and on-resistance, are fundamental to the part's operation. An analogue switch also has many ac specs, such as bandwidth and switching time. All these specs, including leakage current, change - sometimes radically - over temperature. As with all other analogue parts, the switch has specs that all interact and lie along a continuum of values. These specs are not black and white, just shades of gray (Reference 1).
Read the full feaure - Use analogue switches to multiplex your signals

Picture - (Figure 1) A simple symbol represents an analog switch, but stray capacitances abound and small inductances occur because of the presence of bond wires (a). The on-resistance is variable with applied signal and power supply, and the capacitors also change with applied voltage (b).

A call for book reviewers - Next-Gen Mobile Access, Wireless Network Security

2008-07-02T09:56:14Z

Two more books up for grabs, on just one condition... You provide us with a publishable review to a length of at least 300 words.

The two books are:

    Next Generation Mobile Access Technologies
    Implementing TDD
    Edited by Harald Haas, Stephen McLaughlin (Cambridge, ISBN13: 9780521826228)

    Security and Cooperation in Wireless Networks
    Thwarting Malicious and Selfish behaviour in the Age of Ubiquitous Computing
    Levente Buttyán, Jean-Pierre Hubaux (Cambridge, ISBN-13: 9780521873710)

If you are interested, drop me a line at webmaster@electronicsweekly.com

An Engineer in Wonderland - Land speed records, and steam

2008-07-01T14:33:25Z

I am never going to forget those pictures of Thrust SSC with the shockwave angling back across the desert.

There is something magnificent and a little bit mad about land speed records.

A record attempt takes a lot of engineering.

Gone are the days when someone bolted a huge engine into a little tiny car and then just pointed it down a runway.

Which is a good thing in my opinion because a lot of talented people have ended up dead because they took too many chances, or didn't see enough of the potential problems.

]]> Rollie Free, for example.

And dragster driver Barry Bowles, who in the 1970s managed to loose control of the rocket-powered Blond Bombshell on Pendine Sands, allegedly exceeding the British land speed record while careering along upside down - and walking way with only a few bruises.

No, the speeds are so high now that to avoid danger world land speed cars have to be engineering marvels.

Years ago I met the folk behind Thrust SSC and learned first hand that they were:

(a) an extraordinarily talented group of individuals and

(b) conscious of safety first in everything they did.

Aerodynamicist Ron Ayers said he initially turned down a request from Richard Noble to take part in the project because it involved high speeds close to the ground.

Then, on reflection, he asked himself this question: How fast could an inherently stable car shape go - and came up with a number that took him back to Noble.

But there is still room for fun in land speed records if you avoid the unlimited class and stick to velocities that straightforward car technology can handle.

For example, the Bluebird Electric team had a go at the electric-powered record [LINKTO http://www.speedace.info/bluebird_electric_2.htm], but seemed to get bogged down in arguments and I am not sure what happened to it.

And British Steam Car Challenge is hoping to capture the 100 year old steam-powered land speed record.

In 1906 the Stanley Steamer was driven to nearly 130mph, making it the fastest car of any kind at the time.

Broken once since but not within the official rules, according to BSCC, the steam record is still up for grabs.

BSCC's beautifully engineered 360HP three tonne steam turbine car is going to have a crack at 170mph in a couple of months time.

Good luck team BSCC.

'Alice'

alice@electronicsweekly.com, or comment below

An Engineer in Wonderland - The best tin opener?

2008-06-30T08:02:09Z

One of the neatest designs I have ever come across is the military folding tin opener.

I am talking about the little rectangular ones with a hinged tooth, sometimes known as P-38s.
For a few grammes of steel, you get something that opens food containers in under 10s, and is far less dangerous than the ram-in-and-chew-your-way-around portable type that leaves a nasty sharp edge on the container.

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The only disadvantage I have ever come across is the tooth can unfold in transit and poke holes in things or scratch them.

I believe it is a US design and would love to know who invented them.

'Alice' alice@electronicsweekly.com - or reply below.

Let the breaking news come to you, with RSS

2008-06-30T07:25:52Z

The best way to get the latest electronics news as soon as it is published? RSS! Check out all the RSS feeds that are available for Electronics Weekly content. The feed for Latest News can be found here. There are 10 Electronics Weekly feeds you can tap into: News Jobs Products]]> Mannerisms Gadget Freak Made by Monkeys Electro-ramblings Directive Decoder Tech Startups Parallel lines To use an ElectronicsWeekly.com RSS feed you simply need to download and install a RSS reader. Alternatively RSS functionality is built into the personalised areas of sites such as Google & Yahoo, or in Internet browsers such as IE7 and Mozilla Firefox. RSS stands for Really Simple Syndication, by the way. And if you are unfamiliar with this technology, just check out the What is RSS section of our RSS page. electronics news

An Engineer in Wonderland - LED candles

2008-06-27T13:22:17Z

A friend showed me these amazing little things from Philips.

Basically, they are fake night-light-in-a-glasses based on LEDs. I didn't put one next to the real thing, but on their own or in bunches they flicker very realistically.

As far as I can see, there are only two small LEDs in each, plus a rechargeable battery and some kind of pseudorandom driver for the emitters.

]]>
Instead, they charge inductively in a base - operate for 24 hours on a charge - and are turned on and off by tipping them sideways.

I have it on good authority that at least one ancient church is using a lot of them to get the effect of candles without the fire risk.

Neat 'Alice' (alice@electronicsweekly, or reply below)

Vote for 'Best Gadget Freak of the Year'

2008-06-27T09:21:51Z

During the past year, Gadget Freak has highlighted each month 12 unique and wonderful inventions, ranging from an alarm to remind you to close the fridge door through to a device that's specially designed to produce theatrical special effects, like a confetti rainstorm.

Now we put the fate of these gadgets in your hands. Have your say, and vote for your 'Best of the Year' Gadget Freak!

Check out the 12 entrants, featured one-per-month

Simply email webmaster@electronicsweekly.com and state the month of your choice.

An engineer in wonderland - Designers I have known

2008-06-26T15:04:58Z

I have worked with excellent engineers.

On the desk of one I shall call Simon, was a piece of lathe work he produced as a teenager.

It was in three parts, one brass, one aluminium and one steel.

He had bored the brass cylinder, and cut a fine thread on the outside of one end onto which screwed the aluminium in the form of an end cap.

Together, the aluminium and the brass part formed a blind hole about 40mm across and 30 deep which sat on the desk like a cup.

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So fine and accurate was the boring and the turning that when inserted the steel part would rest on the air inside and very slowly descend into the bore, over a minute or so as I remember.

If there was any oil on the surface, it wasn't enough to see.

If you tapped the top of the steel plug as it descended, it would bounce on the air column.

And this from a teenager who turned into electronics rather than mechanics.

When he had a problem, he would sit back in his chair with his hand forming a steeple in front of his face, and stare into middle distance until he thought of an answer, invariably a good one.

I seem to remember the record for his silent pondering was three days.

True, Simon could be a smug sod, but every circuit he designed was as good as that turning.

'Alice' (alice@electronicsweekly.com)

(Picture - MrGilles, 'Lathe at night', under Creative Commons Attribution Licence)

The price of the Symbian Foundation

2008-06-26T10:16:14Z

A little-reported aspect of the Nokia / Symbian manoeuvres earlier this week is the job cuts at UIQ, the User Interface provider for phones from the likes of Sony Ericsson, Motorola and BenQ.

The cost of forming the "open software" Symbian Foundation has a human element. Two hundred people are reportedly losing their jobs from the Swedish-owned operation, out of 375 in total. (The company has offices in London and Budapest, as wells as Ronnerby in Sweden.)

Read AllAboutSymbian.com's report on the layoffs

Electronics giants plummet in new Greanpeace rankings

2008-06-26T07:12:23Z

Greenpeace has released its latest rankings of 18 major electronics companies, and the 'green' scores are plummeting.

In the 8th edition of its Guide to Greener Electronics, only two companies - Sony Ericsson and Sony - score above 5 out of 10. (Click to expand the graphic)

The reason for the decline? Greenpeace has tightened its requirements on electronic waste and toxic chemicals. Newly-added energy criteria also include:

]]> (1) require companies to show their political support for global mandatory cuts in greenhouse gas (GHG) emissions in the post Kyoto political process. Companies must also commit to absolute reductions in GHG emissions from their own operations. Most companies take a limited view of this by only focusing on the energy efficiency of their products

(2) rather than including the production process. The Information and Communications Technology (ICT) sector currently accounts for 2% of global GHG emissions

(3), equal to the aviation industry. As one of the most innovative and fastest growing industries, Greenpeace expects the sector to take leadership in tackling climate change by reducing both their direct and indirect climate carbon footprint.

"Electronics giants pay attention to environmental performance on certain issues, while ignoring others that are just as important. Philips, for example, scores well on chemicals and energy criteria, but scores a zero on e-waste since it has no global take-back polices," said Iza Kruszewska, Greenpeace International Toxics Campaigner. "Philips would score higher if it took responsibility for its own branded e-waste and established equitable global take-back schemes."

Greenpeace's explanation of its new evaluation criteria

See also: Electronics Weekly's WEEE Directive In Full Force, a roundup of content related to the Waste Electrical and Electronic Equipment regulations, and a RoHS special, on the European Directive regarding 'Restriction of Hazardous Substances'.