Dan's Data letters #198Publication date: 10-Apr-2008.
Last modified 29-Aug-2015.
I have recently found a few of those "open a battery to find other smaller batteries inside!!! Save $100's and live off your ill-gotten gains on some desert island" video clips:
What I would like to know - before I head off to my nearest Kmart and flog a battery - what kind of nasty-ness could be inside that one should avoid if one were to open a 6V battery like this one?
I have seen several THIS IS A HOAX videos as well on YouTube, but I just want to know if opening a battery like this is risky, aside from the odd screwdriver cut?
I'll end with my favourite YouTube video on the subject:
It's not dangerous. You could maybe burn yourself if you manage to short the battery out, but that's no big deal. If you stabbed one of the cells inside the battery then the electrolyte could ooze out; for alkaline batteries, that's a potassium hydroxide paste, which you wouldn't want to eat or get in your eyes, and which will burn sensitive skin if you don't wash it off. But it's not seriously hazardous, and you'd have to try pretty hard to come in contact with it.
You'll find separate individually sealed cells inside all carbon-zinc or alkaline batteries that output more than 1.5V. The carbon-zinc ("Super Heavy Duty") and alkaline chemistries only make 1.5 volts per cell, so all carbon-zinc or alkaline batteries with more than 1.5V output contain a string of separate cells of one kind or another. Alkaline 9V batteries contain AAAA-sized cells, for instance (as I've mentioned before), which can in a pinch often be used in place of a AAA.
The lantern-battery thing is a crock, though. The tall-and-square kind of 6V alkaline lantern battery will contain four F-sized cells (basically like D cells, but longer; you can see some rechargeable Fs in my old piece about battery packs). Carbon-zinc 6V lantern batteries may contain four oblong cells instead. (Carbon-zinc 9V batteries usually have oblong cells inside, too.)
More at Snopes, here.
(After this page went up, a reader pointed out that cheaper 6V alkaline lantern batteries these days may just contain four D cells and a spacer, rather than the larger, higher-capacity F cells. This is likely to be more useful to you if you intend to pull the battery apart, but that won't necessarily work out any cheaper than buying normal D cells.)
I currently run Aussie designed and built Whatmough P21 speakers rated at 20 to 120 watts @ 4 ohms as my front pair in a home theatre setup powered by a Harman Kardon AVR5500 receiver rated at 75 watts/channel x 5 @ 8 ohms, and +/- 45 amps instantaneous current. (Straight from the owner's manual.)
My question being if the Harman is rated @ 75watts thru 8ohms what is the power actually being delivered to the Whatmoughs that are rated @ 4ohms? I am not in the situation of having a 75watt rated receiver actually delivering 150watts am I?
Forgive me if this seems a stupid question Dan but my electrical resistance knowledge could quite comfortably fit on the head of a very small pin!!
Any light you can shed would be much appreciated!!
Most of the time, only a few watts. Because of the logarithmic response of the human ear, you need about ten times as much power to make music sound twice as loud. Not that there's any definite point where people will say "yes, that's now 2.000 times as loud as it was before", but most listening is still only done at a few watts per channel, unless you've got stunningly inefficient speakers.
The full power capacity of an amplifier is still useful, for filling the brief demands for very high output that happen when there's (for instance) suddenly a loud bass note. High maximum power means an amp can be running with tons of headroom most of the time, which is a good thing, but you really don't need that much of it. My computer-room sound system is based around one of those tiny Sonic Impact T-amps (as fetishised by loony audiophiles) at the moment; its peak clean output is only a few watts per channel (it can run from AA batteries!), but it has no trouble driving bookshelf speakers to party volume with little distortion, in this small room.
The "20 to 120 watt" power rating for your speakers is telling you to get an amp with at least 20 watt per channel output, exactly so that you'll have that extra headroom. The speakers would actually work just fine with a much weaker amplifier, though classically the best way to blow up your speakers is by hooking them up to a small amp and then turning it all the way up, where it'll go into hard clipping distortion and toast the voice coils. As long as you don't do that, though, small amps are perfectly fine for many applications.
So, on to your question. All other things being equal, if you halve the resistance in a circuit, you double the current and the power. This doesn't apply as neatly as you'd think to audio applications, because the DC resistance of a speaker is only mildly relevant to its AC impedance to an actual audio signal. But you can still expect an amplifier output of X volts, all other things being equal, to deliver about twice as much power into "4-ohm" speakers as into "8-ohm" ones. And if you connect two-ohm speakers (easy enough to improvise by just wiring a pair of four-ohm speakers together in parallel), you get twice the power again.
The limiting factor is how much current the amp can actually deliver, which is determined by a number of components, including its actual transistors (or valves) and the size of its power supply. Any hi-fi amp of reasonable quality is likely to be able to deliver significantly more power into four ohms than into eight, but you shouldn't expect twice the available power from most amps. (Not that this really matters very much, for the reasons I list above.)
Some amps have extremely high current capacity. The giant amps used in car audio, for instance, are usually running from only 12 to 13.8 volts. This creates a problem, because the output voltage of an amplifier cannot be higher than its power supply voltage.
So to get monstrous power out of these things, you can either build a big beefy DC-to-DC converter into the supply side that gives the amp enough input volts to be able to push four-ohm speakers (the standard nominal impedance for car speakers) to a thousand watts or whatever, or you can make an amp with less step-up on the input side, but colossal current capacity. Then you connect it to a bank of ONE-ohm subwoofers all wired in parallel with cables like tree trunks, and the job's done.
For home users, the only thing you have to remember about the four/eight-ohm thing is that four-ohm speakers will probably be considerably louder at a given volume control setting than eight-ohm speakers, which can make setting up surround systems more challenging.
There are other large factors in play here, though. Sealed-box speakers are much less efficient than ported speakers, for instance, and larger speakers are generally more efficient than smaller ones. So it's quite possible for a large ported eight-ohm loudspeaker to be louder at a given volume control setting than a small sealed-box four-ohm speaker.
I read today an article describing an exhaust-heated water injection system to boost an engine mileage while reducing emissions dramatically (Gillier-Pantone system, inspired by Charles Nelson Pogue's "bubbler"). Details relate this principle was used on Spitfire fighter to boost their horsepower about 30%, and are successfully used on a number of French industrial tractors.
This doesn't look like the typical scam, at least considering it involves more that dropping a pill into the tank. What do you think?
I see no reason to suppose that this would work.
Water injection was, and is, used in very-high-performance engines to cool the intake charge and thus allow you to pack more fuel/air mixture into the cylinders. In this role it can in theory do the same sort of thing as a turbocharger or supercharger, but is normally used along with those devices, because it offsets their natural tendency to greatly heat the incoming air charge when they compress it.
(This of course means that water vapour injection systems, which pre-heat the water, are rather nutty.)
Water injection is apparently also effective at preventing detonation or "knock".
But packing in more fuel/air mixture is only useful if you want to be able to get even more power than is already available at full throttle. And inhibiting knock is unnecessary in everyday engines that aren't running high compression ratios, and already have fuel with a high enough octane rating.
(Practically every scammy fuel-gadget is supposed to raise the fuel's octane rating, because people think "octane" equals "power". Yes, high-powered high-compression engines need high-octane fuel, but that doesn't mean that feeding higher octane fuel to an ordinary engine will magically turn it into a high-powered one. Similarly, bodybuilders may drink a dozen eggs for breakfast, but if you do the same, it won't make you muscular.)
It's possible that the ideas about water improving emissions were spawned by steam injection in gas flaring. Injecting steam into a gas flame really does reduce the amount of smoke the flame creates. But even if injecting water into a combustion chamber could work the same way, the gas-flare flames are smoky because the gas isn't burning very well, leaving lots of carbon that hasn't combined with oxygen. Combustion inside a correctly tuned engine is almost perfectly complete, so there's practically no soot to get rid of.
And regrettably, this actually is a quite common scam. Most "water injection" scams today are just variants on the "run your car on water" nonsense that's had a great renaissance in the last few years, but it's also easy to find water injection doodads that're supposed, as Tony says above, to do away with the costly high-powered pumps that real water injection rigs need by allowing manifold vacuum to suck the water into the engine. Which can only possibly work when the engine is running at less than full throttle, which is when you don't need water injection at all.
Just blowing water into an engine's air intake won't do anything noticeable. It needs to be injected after the incoming air has been compressed by your whatever-charger, or you will, in essence, be using the water to cool your turbo/supercharger, rather than to cool the fuel/air charge.
Because of the charge-cooling effect, it's perfectly possible to make engines run more efficiently on "damp air", especially if you considerably modify them - new ECU mapping with advanced spark, and preferably a higher compression ratio too. There's no reason to suppose you'd get lower emissions as a result, though. Given how finely balanced modern engine management systems are, pumping anything unexpected into the combustion chamber is likely to give you a vehicle that dismally fails the smog check.
I was at KipKay.com and there was a video idea there that said if I taped some neodymium magnets under my motorcycle I would not be left sitting at the stop light for so long, because my motorcycle won't trigger the light to change
I've sat quite a long time at a few lights. Do you think this would work?
(And no, I'm not exactly overjoyed that he's now working for Make Magazine, either.)
Lots of people have tried putting magnets on bicycles and motorcycles to get induction loop vehicle sensors - which work much like a metal detector - to notice them. There are even commercial products that seem to be nothing more than a magnet in a plastic box. But I know of no reason why this would actually work.
Passing a magnet over an induction loop will induce a little current in it, but it won't change the loop's actual inductance any more than a similar-sized lump of unmagnetised metal with the same conductivity would. It's change in inductance that causes the vehicle detector to trigger - here's how these sensors work.
It's perfectly possible for many of these sensors to detect even a bicycle; they just need to have the sensitivity turned up far enough. (And conversely, the sensitivity can be turned way down for unusual situations, like when there's a special turning lane for buses and the turn arrow's not meant to light up for cars.) I think many people who've convinced themselves that magnets work have actually just been waiting at lights that now have higher-sensitivity vehicle sensors than they used to have.
There are now video-camera-based sensors, too. The old induction loop may still be there, but it may not be connected to anything any more.
There's some more discussion of this issue here.
(Some time after this page went up, I discovered this gadget, an active magnetic transmitter that can trigger various loop sensors, but has to be manually adjusted to the different characteristics of different sensors.)
I was recently asked about the "SunCube" solar energy devices by a colleague. A brief scan of their Web site sent up a few red flags, things like being able to "register my interest in buying SunCubes in one of GGE's SunCube™ solar farms" - i.e. buy into the operation (I'm sure for a very reasonable price). Plus their claims of large performance gains over more standard photovoltaic panels, and the fact that their "SunCube International Group" representing dozens of countries can't afford a better-laid-out website.
A bit of a Google search turns up some controversy. Oh, and they have appeared on Today Tonight, and won something off the New Inventors, both programs well known for their highly sceptical and fact-based reporting...
Anyway, I'm wondering if you know anything about them, or care to find out?
As you say, this seems to be yet another awesome success brought to you by the New Inventors Hit Machine.
After the New Inventors thing (about the "SunBall", a previous design with different geometry...) I looked into the company, Green and Gold Energy, myself. Then I discovered that they had no actual product, and no obvious prospect of producing one in the near future, so I put 'em on the back burner and forgot about them. That was 2005 (with delivery promised in early 2006). This is 2008. And still nothing.
The basic idea of concentrating light onto high-temperature, high-efficiency solar cells is a perfectly good one, provided you can prevent the cells from burning up, and accurately track the sun. Accurate tracking is of course vitally important for this sort of device; a conventional array will work OK when the sun hits it from an angle, but a focussed hot-spot will miss the little cells altogether if the collector isn't quite lined up.
Whether this company is ever actually going to make a device that solves these problems is highly questionable.
I wouldn't bother with them until they've actually got a working product on the shelves of your local enviro-store. I suspect this will never happen.
EDIT: It later transpired that the whole SunCube thing was just a good old-fashioned scam.
I have an idea on how to run an electric powerplant, using magnetic energy, and only magnetic energy. After reading one of your articles, it seems to me that you have the knowledge to implement my plan. I am looking to patent an invention, and then bring it to market. It would require no investment on your part. I would split any profit 50/50.
This is not a scam, I am a real person. I have some funds to invest in this project. If successful, we can help our country be less dependent on foreign oil.
Are you interested? Please let me know.
After reading more of my articles, I am afraid it will become clear to you that I am quite certain your plan is doomed.
I wish you all the luck in the world, but I strongly urge you to direct your attention toward a field of endeavour that does not have a zero per cent success rate, despite many thousands of attempts over hundreds of years.
I recently read a post on a forum from a guy who claimed 12 years ago he created the "Eternity" battery. A battery that could run forever. When it was drained you simply rested it and it magically recharged. But of course he says it never got anywhere because of the effect it would have on the world. He also claims articles about it were published in magazines.
I searched the Web and found nothing, no hint. Is this guy BSing or am I not looking hard enough?
I've never heard of it. I've heard of many similar things, though, articles about which have been published in all sorts of magazines and newspapers. So are articles about people having sex with yetis and angels helping to build the Pyramids, of course.
And yes, such a battery would obviously violate the usual list of fundamental physical laws.
If the Eternity Battery works, though, it is incredibly stupid, and I would go so far as to say very clearly seriously criminal, that this guy has not just published far and wide the plans for making the thing, and thereby done an end run around the Energy Industry Conspiracy which he as usual alleges exists. If he did so, he could then either just anonymously bask in the knowledge that he's the most important human since the invention of fire-making, or he could put his name on the end of the plans and enjoy the boundless adulation of the entire planet, at the possible cost of vindictive assassination.
Since he has not released the plans for his miracle battery - and they could be distributed around the world in a matter of minutes today, just like the thousands of lunatic screeds and fraudulent "documentaries" that similarly circulate in the "Miscellaneous" category of the world's BitTorrent sites - it seems clear to me that this guy has on his hands the blood of everyone who's died or suffered because of the world's current lack of free energy.
This act makes him the greatest criminal in world history by several orders of magnitude, of course, so I suppose it's hardly surprising that he's lying a bit low.
But he could change all that in five minutes.
Why hasn't he?