Dan's Data letters #156
Publication date: 9 December 2005.Last modified 03-Dec-2011.
Subcontinental gaming
I am getting an Xbox 360 for my very own self this Christmas. No, my rich uncle didn't die, I just decided that I needed some tender loving care of the PGR 3 kind.
Aaanyway, the thing is, the Xbox 360 is being purchased from the United States of A, 'cause Microsoft does not deem it fit to launch the 360 in the backward Indian subcontinent. They probably think that our holy men have no use for the 360.
So the US has 110V, 50Hz power, while we have 220V 60Hz power. I looked around on the net and found that the 360 draws about 200 watts. So I went down to the local electrical chappie, and had him make me a 220v-110v step-down converter, which is rated at 450 watts. It's a big, heavy box, with a transformer inside. Now my questions are:
1. Did I miss anything? This ought to work well, right, or will it send the 360 to the land of dead consoles?
2. The chappie put a multimeter across the terminals and showed me the output, and it was 105V. Does a 5V differential make a lot of difference?
I just wanted to know your opinion. I searched for 220v-110v converters on the web and found many, but they are all heavy, and the friend who is bringing the Xbox can't carry that much luggage.
I hope to get a reply from you. I'll sweeten the deal by throwing in 10 hours of free play on my 360 if you are ever in Jaipur, India! :)
Aditya
Answer:
Yes, it should be fine. The console shouldn't care about the frequency difference. Modern
switchmode power supplies
are not very fussy, even about horrible power supply waveforms - you can run them from old gasoline generators with
no trouble, as long as the voltage isn't way out of spec.
The low output voltage shouldn't be a problem, either. It's normal for residential power to sag and surge by more than that, and appliances are made to handle it. People who live somewhere where the unfiltered mains power commonly blows up unprotected appliances should apply their normal power filtering procedures to stepped-down devices as well, of course - just run the step-down transformer from your UPS or power conditioner or whatever, and the transformer should provide a bit more protection from sags and spikes - but mere voltage regulation within 10% of the rated voltage should be easy for just about any switchmode device.
Then again, problems with overheating 360 PSUs are apparently not totally uncommon (some early adopters have complained loudly, Microsoft's insisted that only 0.00000000037% of 360s have the problem, et cetera), so I'd recommend you put the big power brick up above the ground a bit. On an inverted dish drainer, or something; hanging it in the air with string strikes me as an unnecessarily precarious procedure), and maybe point a desk fan at it, especially on hot days. I used to do this exact thing with the struggling stock power supply for my thoroughly expanded Amiga 500 (a couple of pickle jars kept it up off the vent-clogging carpet), before I replaced it with a re-plugged PC AT PSU.
Your 360's PSU may not have the overheating problem - most don't - but if it does, it'll be a pain for you to get a new one, so you might as well take precautions.
And, of course, if your step-down converter was made by a little man in a little shop with very little knowledge about what he was doing, then all bets could be off. But I wouldn't be particularly worried, personally.
Won't somebody think of the wide-awake children?!
According to this NYT report (usual registration stuff required), this Kool-Aid-like drink mix stuff is slugging five-year-olds with "a cup and a half of coffee" per serving.
Holy cow! Won't the little ones get palpitations or something from that? I know my kids freaked out if I even let them drink a whole can of Coke at that age (which I seldom did), and isn't that meant to be equivalent to a third of a cup of a coffee, or something?
Susan
Answer:
Loading kidlets up with drugs of any kind to improve their sporting performance isn't, if you ask me, a very good
idea, if only because of the mixed message it sends. People keep saying that drugs in sport are bad, m'kay, and in
any case they should be perfectly unnecessary in children's sport that's all meant to be about the thrill of the game,
physical fitness and all the rest of that stuff that I never bought for one second when people made
me dress up in a damn fool "sports uniform"
and trudge off somewhere to move balls of various sizes around in a very inefficient fashion. Oh, but if all of the
parents approve of every kid on the Under 12s Soccer Team toking heavily on a Nembutal inhaler before the game, whether
or not they've got asthma, then that's OK. Likewise,
Caffeine For All. Roger that.
But regardless of all that, the New York Times reporter screwed up the numbers. The "Spark" concoction is not actually especially potent.
Lower down, the NYT article says that their "cup and a half of coffee" for the ages-4-to-11 stuff means 60 milligrams of caffeine, and 120 milligrams for the higher powered stuff aimed at people aged 12 and up.
Insofar as there is an ISO Standard Cup Of Coffee, it contains about 100 milligrams of caffeine, the same amount you get in various OTC wakey-wakey pills (No-Doz, et cetera; Vivarin is 200mg). It's easy to get considerably more than 100mg of caffeine into a cup before you get into the spoon-dissolving espresso range (eight fluid ounces of espresso will probably contain more than 400mg of caffeine, but a cup of drip coffee can be above 150mg), but your average cup is likely to be much closer to 100mg.
Instant coffee has less caffeine, but you'd still have to make a pretty weak brew to get less than 60mg per cup - that's about the caffeine content of decent tea.
The NYT piece is, therefore, overstating the strength of the Spark drinks by a factor of about 1.7, and unnecessarily alarming adults who know how wired they get on three cups of coffee.
The 120mg of caffeine in the stronger version of "Spark" certainly will give a 13-year-old a sizeable boost, but only about as much as three and a half cans of Coca-Cola at US strength (caffeine content varies somewhat in different countries). It'd only take 2.6 cans of Diet Coke, which has more caffeine.
To get as much caffeine as there is in three real cups of normal brewed coffee, a kid would have to knock back almost nine cans of American Coke.
The actual amount you get in a "cup" of coffee of course depends on the size of the cup as well as the strength of what's in it. Standard American coffee cups are six or seven US fluid ounces depending on who you ask (one oz = 29.6ml), which is about normal here in Australia too, but many people all around the world drink much larger cups than that. If you believe a "cup" to be well over 250ml, the NYT claims about 1.5 or three "cups" per serving of "Spark" become even more alarming. Three 16 ounce Starbucks "Grande" cups might well contain more than 700 milligrams of caffeine, which is a seriously jitter-inducing amount even for heavy coffee drinkers. The maximum effective dose of caffeine for normal adult humans is around 300mg; it takes a great deal more before the stuff will actually cause you physical harm, but above 300mg in a single dose just gives you more unpleasant side effects with no more positive effects.
I don't think anyone, young or old, actually needs "Spark", or anything else made by AdvoCare (isn't that what you had to say to get into Exodus' castle?), but that could just be my aversion to AdvoCare's motto talking.
I mean, seriously - "Health, Hope and a Future"? That's what passes for a slogan these days?
Remember: Without AdvoCare products, your children have no future!
(AdvoCare would appear to have scrubbed their site of any promotion of the Spark drinks for kids, by the way. "Health, Hope, and a PR Department That Notices Bad Publicity".)
I never tire of the things
I guess you've seen these already, but they do seem pretty nice. :)
Mats
Answer:
There are lots of other NIB magnet dealers out there, of course;
ForceField, Amazing Magnets,
Engineered Concepts, and plenty more, including scads of eBay stores.
United Nuclear (mentioned previously here; they've also got lots of cool scientific supplies, but don't ship outside the States unless assisted; that's just as well for weird chemicals that're likely to get intercepted by Customs, mind you) seem to be an OK source, but their claim that their N40-plus magnets are "much, much stronger than common Neodymium magnets (N28, N35, or N38)" is false, as I explain here. The N-rating tells you, essentially, how strongly the NIB material can be magnetised - it's a measurement in megagauss oersteds, or MGOe. Usually the material is magnetised about as strongly as it can be, but the strength difference between N45 and the more common, cheaper N38, will still be only about 10% at best.
Unless that last few per cent really matters to you, you should only worry about the price when buying NIB magnets of a given shape, size and surface coating.
There should be more squid products
When I heard about these "PowerSquids" I knew you'd be the kinda guy to want to see them. Not sure if that's a compliment or not. Anyway, they are basically a normal power board with mini extension cords on each socket to facilitate the good old wall wart. Of course, it's not just called a powerboard any more, now it's a "dynamic power delivery device".
What did interest me was their claim that the surge protection is "the best money can buy". They use metal oxide varistors as part of their power surge solution, which apparently offer 27% greater capacity (than what?). Anyway, thought this might be up your alley.
Frank
Answer:
On the one hand, I like the PowerSquid idea. Powerboards have significant physical limitations, which this multi-Y-adapter
design, whether commercial or home-made,
avoids. It might be a bit rough on plugpacks if they end up having their cable exit points folded hard against the
floor, but you can just keep an eye out for that.
On the other hand, any claim that their surge protection is the best money can buy (I don't think the PowerSquid people have actually made such a claim themselves) is a bunch of hooey.
Some press release or other quotes different PowerSquid models as having ratings "from 1020 to 3280 joules". This is not entirely remarkable, as "surge protector" boards with ratings close to 3000 joules have been around for a while.
"Ultra-MOVs" would appear to be a marketing creation - perhaps they pack a bit more capacity into a MOV that's no bigger, or something, but surge protector manufacturers have always been able to just cram more and/or bigger MOVs in there, or even Silicon Avalanche Diodes (see this page), if they're willing to accept the extra manufacturing cost.
None of the makers of chain-store surge protectors, including the people who're happy to overengineer the heck out of things that don't need it, do this.
Having a "joule" rating at all is actually a bad thing for a power conditioning gadget. That rating tells you how big a spike the device can be expected to successfully sink when new, but it's more useful as an estimate of the device's lifespan. The more joules, the longer your "surge protector" will last before it turns into a mere powerboard - and, maybe, informs you of that fact with a light or buzzer. And maybe doesn't.
Safety regulations can also make lightweight surge protectors - any surge blocking device that doesn't contain a damn great transformer, feel pretty much like its entire casing is full to the brim with iron, and have no clear maximum surge absorption rating - less effective than they'd otherwise be.
The US UL1449 standard, for instance, requires (among other things) that a surge protector presented with a surge much larger than it can handle should not blow up and set fire to your carpet. Fair enough. Unfortunately, the cheapest way to make this happen is to just put a fuse in line with the MOVs that do the actual surge-catching, so that the fuse pops before the MOVs do.
This looks fine at first glance, but there's actually a pretty wide margin between "MOVs killed in action" and "whole powerboard in flames", and the fuse means you lose most-to-all of that extra leeway. When the fuse blows, of necessity at some current level rather lower than the maximum the MOVs could handle without starting a fire, the surge has nowhere to go but into your supposedly protected equipment. Within which various other more or less expensive components will, in turn, hurl themselves on the grenade.
A more expensive way of satisfying the UL requirement would be to use bigger MOVs, and to make the surge suppressor itself tougher and less explodable or burnable. A low-flammability plastic casing inside a steel external box, say, or potting the flame-prone components in epoxy, or something.
But it's far cheaper to use small MOVs, a fuse, and plastic, and plaster over the flaws with great big Connected Equipment Warranties, about the proven-or-potential weaseliness of which I have complained previously (also mentioned here).
Interestingly, Flexity (the PowerSquid manufacturers) seem to have bucked the trend here, but only by arranging the components slightly differently. Their "Tripwire™ Circuit catastrophic event protection" sounds to me like the fuse not in line with the MOVs, but sitting right on the active wire before the MOVs connect active to neutral. It could be something fancier, of course, but a fuse - or, more likely, one of the ten cent circuit breakers that adorn most powerboards - would do the job described.
The fuse/breaker blows/trips in the same way, but it cuts power to the whole Squid when it does. This is not a bad idea, for many purposes - if it's a breaker, you just press a button and you're back in business, because the surge probably didn't fry the breaker, and with any luck didn't fry your gear before the breaker broke. But if a nuisance trip powers down something that matters to your small business online shopping cart system five minutes after everyone's gone home, and you've neglected to install a device that automatically pokes the Squid's button every ten minutes, you're likely to be Irked.
Flexity also definitely do make some claims that've fallen out of the marketing tree and hit many branches on the way down.
Here, for instance, they say that "Electromagnetic interference in the current has been shown to hurt performance and be a source of errors and damage to sensitive components".
No it hasn't, as I've said before, unless it's incredibly strong (power lines waving right in front of a military radar...) or your gear has extremely, probably even illegally, crappy power supplies.
This claim may, just possibly, apply for certain fairly obscure applications - hello, homebuilt valve amplifier fanatics - but anything that's got a normal PSU with a row of chunky capacitors in it will, most probably, eat great amounts of incoming RFI with no trouble at all.
Incidentally, if you're wondering what the "sidactors" referenced here are, they're a kind of branded thyristor made by Littelfuse, and you can read about what they do in the riveting PDF here.
They may, indeed, give PowerSquids unusually good, or at least unusually durable, data line filtering. I dunno. They're not very expensive items, at a few bucks per unit retail tops, but that does qualify as "expensive" by the standards of surge protector manufacturers.
The one definite thing the PowerSquids have going for them, if you ask me, is the obvious one - their cool and useful form factor. You can emulate this with other off-the-shelf gear or, of course, solder together butchered mains leads as you like. I used to do that to make IEC-male-to-mains-female adapters for UPSes. But those are (finally) off-the-shelf items now as well, and just buying the basic less-marketing-hype PowerSquids is a good idea too, if you don't want to fool around doing the same thing the multiple-parts way.
I'm still not itching to get one, though, for the simple reason that Flexity don't make them with Australian connectors. I'm sure there'll be an Aussie-plug Taiwanese knockoff selling on eBay soon enough, though!
