Dan's Data letters #150
Publication date: 27 September 2005.Last modified 03-Dec-2011.
Barrel plugs, begone!
Why o why do I not have an inductive coffee table? A platform onto which I can fling my cell phone, iPod, laptop and keychain torch and have them happily charge without additional plugging or fiddling? My understanding is that this technology is efficient and functional. Yet the only consumer applications seem to be overengineered toothbrushes and defunct electric cars. What gives?
And, on a related note: am I right in imagining that an inductive charger could be used by devices expecting a variety of different input voltages (presumably by ignoring every nth cycle, then smoothing out the current)? Or would a different inductive charger be necessary for every device?
Tom
Answer:
It may yet happen, but it's not a perfect solution, for technical and marketing
reasons.
First up, it's... fairly efficient. Basically, inductive charging makes an arbitrary air-cored transformer out of the coffee table (or smaller charging pad, or whatever) and the coil(s) in the gadget(s) being charged.
I don't know the exact numbers, but I think you get about 0.7 efficiency out of the "transformer" (or less, if you put a big metal thing on the charger to warm up; transformer efficiency is typically much better than this, but air cored transformers don't work well unless the coils overlap, which is of course impossible when they're in separate enclosures) and lose a bit more in the frequency conversion (because the air cored transformer, she no work at low frequency), so you end up with, at best, about the same lousy efficiency as old-style heavy linear "wall warts" (as opposed to the new-style lightweight switchmode ones).
Not-so-great efficiency is one of the reasons why this technology hasn't yet arrived for things like laptops that need considerable charge power. If you're just charging an electric toothbrush (which, of course, is best made with no holes in the casing to let water in, making it an ideal candidate for inductive charging) then wasting half of the two watt (or whatever) power as heat is no big deal. If you want to charge an 80 watt-hour laptop pack in two hours, though, you'll need to put at least 50 watts into it (to allow for the inefficiency of the electrochemical charging process itself); wasting another 50 watts is going to warm your table up a bit.
Also, the things are going to be hard to sell in much of Europe, or anywhere else where people are applying the Precautionary Principle to, um, anything involving electrons. Lots of people are Not Happy about electromagnetic radiation in general (see below...); if they're worrying about the distance between their clock radio and their head, they're not going to buy a coffee table that makes their stainless steel cups sing.
You certainly wouldn't need a different charger for each device, though - just use a different number of turns in the device's charge coil. Vprimary / Vsecondary = Tprimary / Tsecondary, where T is the number of turns on the coil.
Scattering multiple different secondary coils all over the primary will, of course, probably be even worse news for efficiency. A reader's also pointed out to me that any circular metal objects put on an inductive charger - watches, bracelets, rings - will act as shorted secondaries and heat up as fast as the charger will let them. Manufacturers could guard against that easily enough with the same automatic overload protection that causes my bench power supply to just light a reproachful little LED (rather than blow a fuse) when I try arc welding with nails, but it's another hurdle for the technology to clear.
Vaporboard
I've been getting excited over the idea behind the Optimus keyboard, it seems to have both the functionality and creativity which will allow it to be sold and supported (even if it is the "elite" few... you know... those art students who major in sociology). Anyway. Take a look at it (and some of the other stupidly over-designed products the company has to offer); it might get you as interested.
It would be great if the user had some variety of software for the product which would allow you to map it out for each program.
Willem
Answer:
That keyboard was the flavour of the week a little while
ago, but it still doesn't exist as anything more
than rendered images. Lebedev do real industrial design, though
so it's quite possible the Optimus will make it to market.
The obvious stuff, as shown in the renders, isn't really all that useful if you ask me; it'd help you learn hotkeys for new apps, but once you learn them you don't need the cues any more. Special keys to run particular apps? Gee, there're only about a million keyboards that have those already.
There are also some serious pitfalls to the design - will little OLED/LCD/whatever displays survive being typed on all day, for instance? And the thing's got a dead flat layout, which needs only the addition of standard squishy rubber dome keyswitches to turn the 'board into an ergonomic disaster area.
Use of the keyboard as an output device could be cool, though; free-form press-this-button-for-this-action stuff from various applications could be quite handy in some cases, plus your keyboard could go all disco inferno when your screensaver cut in.
Art. Lebedev is definitely cool, though, if only for their celebrated barcode-logo series.
[UPDATE: The development path of what ended up being called the Optimus Maximus keyboard was about as long and rocky as that of the Bugatti Veyron, but it finally did make it to market, for a price of forty-four thousand roubles. Or only $US1589.99 from ThinkGeek, on the rare occasions when they have stock. Since the Maximus is actually lousy to type on, you might prefer the "Mini Three", with has only three display-keys, and costs a mere 4,300 roubles. As I write this, ThinkGeek have it in stock, for $US134.99.]
Capable of inhaling a whole team of technicians
I don't know if you were aiming to refer to the ultimate jet engine in your recent letters, or if the 747 was just the first plane that came to mind. But you should check out the engines for the 777, they make the ones on the 747 look like twisted rubber bands. Apparently the GE90-110B fitted to some models is larger in diameter than the original 737, which I'm sure you'll agree is pretty cool.
Ian
Answer:
I was aware of the beefiness of the 777's engines (it's only got two engines to the 747's four, but the total thrust
of the more powerful 777 engine options exceeds the total thrust of the earliest 747s) - the 747's just the
ISO Standard Jumbo.
The relative scale of the engines is particularly apparent on the 747 test mule!
Deadly emanations
I am a GP in New Zealand and my daughter and I would really like to do something about the cellphone situation. She is 12 and a very able speaker. We are both concerned about the level of cellphone radiation her age group is exposing itself to.
In short, we are motivated to do something about it. Our plan:
- To try and find one or two good cellphone shielding devices that we can promote.
- Go into schools and talk to the students, the parent/teacher organisations, and do fundraisers selling cellphone protection devices.
Basically, we're not hopeful that we will get the kids to stop using cellphones; we are hopeful that we can find something that is effective and hopefully "trendy" looking enough that we can save our young people from an epidemic of brain cancers 10 to 20 years from now.
If we don't do this - who knows? I can protect my kids by educating them, but I've got no access to my children's future partners!
I have been trying to research different products. There is the Microshield out of the UK (I don't know if this has enough "trendyness" though) and the SAR Shield device (only 89% protection though). There are also ferrite beads (but they need a earpiece, and even if the kids accept them, what happens if ear pieces become trendy and some use them without the beads - this will increase the damage).
I was wondering if you have any recommendations?
Elizabeth
Answer:
The "cellphone situation"? What situation?
I'm not being facetious - I just see little reason to be concerned about the putative risks to human health of even quite heavy cellphone use. The evidence most certainly does not suggest that there'll be "an epidemic of brain cancers 10-20 years from now".
Mobile phone radiation isn't ionising, there are no inhalable particulates, and the modern world we live in means most of us are surrounded by EMR at various frequencies and energy levels all day, every day. And yet, provided we don't drink, smoke, eat or laze ourselves into an early grave, human beings have never had a better chance of living to see 100.
Perhaps the relatively new phenomenon of cellphone radiation is going to result in a sudden epidemic of some dreadful disease at some point in the future, but the evidence to date does not suggest that it's any more of a risk factor than a million other things. Yes, cellphone companies are busy covering up inconvenient studies in exactly the way that tobacco companies did, but the fact that they don't want bad publicity does not mean there's actually an underlying Ghastly Epidemic about to happen. Dow Corning went broke because of their payouts over diseases which their breast implants did not actually cause, after all; no doubt Nokia and Motorola are not keen on the same thing happening to them.
Given the significant number of well-established risks to health and happiness which face kids today, I think effort put towards protecting them from cellphone radiation is misplaced.
Here's a good backgrounder.
The Microshield thing appears to actually do what it's meant to do (putting aside the notion of whether that actually does need to be done...); it's been around for a while, too.
Mind you, any site that says "ANECDOTAL EVIDENCE : IGNORE IT AT YOUR PERIL!" automatically gets an F minus from me.
The SAR Shield, on the other hand, isn't quite a classic stick-on scam product, since it does at least go on the antenna and cover the side facing your head, and nobody's claiming proof of efficacy via iridology or chi analysis or something. But, like all radiation blockers that don't envelope the whole phone, I don't see how it can achieve much of anything on modern phones.
Yes, the SAR Shield people have test results from a reputable German lab (those tests may well be perfectly kosher, but my psychic powers tell me that attempts to chase up the people who did the tests or merely verify that they ever actually happened will peter out to nothing; I've gone after these sorts of rabbits before), but they've also got a "30 day money back guarantee". I guess that means if you're dead inside a month, you get your $US20 back.
I'd just use a hands-free kit of some kind. If (and it's a big if) there's significant radiation from an earpiece cable, you can loop it through a ferrite bead; it won't do any harm to do that anyway. Or you can use a Bluetooth earpiece, unless someone's saying they cause cancer of the earlobe now or something.
Mind you, since full precautions appear to mean you should "never hold the phone near your eyes, breasts, testicles or pregnant abdomen, kidneys or liver", you apparently have to strap the phone to your ankle, or give it to someone you don't like to hold.
If you want to campaign to improve the health of teenagers, campaign to get them to eat better and exercise more. The risks to quality and quantity of life they face by sitting around playing video games (or, for that matter, talking on any kind of phone) and habitually eating at McDonald's are clearly established and quite serious.
Or campaign against the War On Some Drugs, and its maniacal desire to make sure that people who just want to be happy end up imprisoned or dead. Or just campaign for better drug education, to stop kids thinking that since government warnings about smoking dope are largely lies, similar warnings about other drugs must also be rubbish.
Or, if you're really concerned about keeping phone EMR exposure down, campaign for more cellphone towers to be built, so the phones won't have to step up to full power as often!
(If you do that, I'll send you ten bucks if you use the phrase "Won't somebody think of the children?!")
Hydrogen, gasoline, blah blah blah...
I (being a not-so-gullible sort of person) was reading about your encounters with... khm... less than legit stuff and its assorted salespeople with great pleasure. I just happened to notice The Montreal Gazette's "Can this man save the world?"/instant free energy from H2 piece, and I'm less than convinced (unlike most of the press guys), to put it very mildly. I'd just love to read what you think about it.
Attila
Answer:
This piece has been pretty widely reprinted, and very widely commented upon. It's caused considerable confusion among
people who think it's talking about one of those stupid run-your-car-on-hydrogen-you-generate-with-some-magic-onboard-device
schemes (see this page, and MythBusters season 3, episode 16). Hydrogen injection
(injection of some relatively small amount of hydrogen along with the conventional fuel-air charge) is not nearly
that nuts, but neither is it anything very remarkable,
unless this inventor really has come up with some amazing new insight that's, um, not mentioned in the article.
The journalist who wrote the piece, unfortunately, don't know nothin' 'bout nothin'.
"Most internal combustion engines operate at about 35 per cent efficiency. This means that only 35 per cent of the fuel is fully burned" is wrong. Internal combustion engines do indeed have miserable efficiency, but that's because they waste tons of energy, mainly as heat. They're physically incapable of being a whole lot more efficient; the Carnot cycle defines the outer edge of the possible efficiency envelope for engines, and with room-temperature intake air and petrol-engine-temperature exhaust, it sets an absolute maximum Physics-Experiment-Land efficiency of sixty-something per cent. Real world engines can't hope to get very close to that, but they do burn their fuel very well already, thank you; stick 'em in an insulated box and measure the energy coming out of them as crankshaft power, heat and noise, and you'll see that they're accounting for the theoretical energy content of their fuel almost completely.
This Slashdot post just about covers it, I think.
As the poster points out, if the guy who came up with this thing couldn't get anything useful out of combustion-enhancer-injection, then it probably ain't gonna happen.
You. Outside. Now.
dear webmaster,
i would be interested in running a banner advert for my site www.lifetechnology.org at your site. what are your monthly traffic figures and would you be able to advise me on ad rates for a standard sized banner please.would payment via paypal be acceptable to you?
thanks and best wishes,
rory mccaffrey
Answer:
Um... have you looked at my site?
Start here, and see how you go.
Then please switch to a business that isn't a total fraud.
Thank you for confirming my rule of thumb that people who sell stupid, stupid, stupid woo-woo "alternative medicine" products are, themselves, really, really stupid.
