Dan's Data letters #78
Publication date: 7 December 2003.Last modified 03-Dec-2011.
DVD dodges
I just dropped some serious coin (for a cheapskate like me, at least) on a Toshiba Tecra S1 laptop (PDF specs here). One of the primary drivers for this was its nine-cell battery and five-plus hour battery life. A model from the same line (but with much higher specs) pounded out 6+ hours in a test, so I'm hoping the 5+ hours is a realistic usage estimate. My guess is I'll be about 4 hours of DVD playback on a new battery. I think IBM is the king of battery life, but the Toshiba Centrino is a close second at a cheaper price.
One reason I wanted long battery life is because I spend lots of time on planes, many of which do not have those nifty power plugs for your laptop - and I want to watch DVDs.
So my question is this - what are some tricks to get the most out of your battery when watching DVDs? If you watch in "letterbox" format and only use 2/3 of the screen will that consume less power because fewer pixels are being changed? What about copying the entire DVD (or DVDs) at home to the hard drive (when plugged into the wall) and then watching the DVDs from the hard drive instead of the DVD drive? Would that prolong the battery life?
Lastly, what's all this I hear about "properly conditioning your battery to ensure proper performance"? Should I charge and drain the battery a few times when the laptop gets delivered? Or is this "conditioning" talk all bunk?
Brian
Answer:
The only screen-related battery life improvement you can get is by just
turning the brightness down, but that won't do anything much.
Copying the VOBs from the DVDs to the hard drive is more useful. Optical drives are relatively large power consumers in laptops. Still, compared with the combined mainboard and CPU power drain while you're doing something mildly computationally intense like watching a DVD, the power saving from this isn't going to be huge, either.
What you could do instead is get yourself an outboard battery.
In case anyone cares, the six and nine cell batteries for this laptop both, as is normal these days, use lithium ion cells, which have a nominal voltage of 3.6 volts per cell, versus the 1.2 volts per cell of NiMH and NiCd. These cells are arranged in strings of three, which adds up to 10.8 volts per string - the same as you'd get from a string of nine 1.2 volt cells.
Each cell of these batteries has 2150mAh capacity at 3.6 volts (7.74 watt-hours); each string of three cells has 2150mAh capacity at 10.8 volts (23.22 watt-hours).
The six cell battery has two parallel strings of three cells; the nine cell battery has three strings. You could also, in theory at least, have a three cell battery with just one string of cells in it; that'd have 2150mAh capacity, and probably wouldn't be too happy about the current it was being asked to deliver.
Three hours of battery life (let's be a bit pessimistic) from the nine cell pack would mean a current draw of 2.15 amps, which is not horribly high for large standard-duty NiMH cells - or for dirt cheap sealed lead acid (SLA) batteries, for that matter, if you can get the thing to run from 12V. The Tecra wants 15V input from its AC adapter, but might tolerate only 12. People have run all kinds of unlikely things from bargain-priced SLA bricks; it's nice to have a battery so cheap that you don't care if it gets murdered.
Lithium ion cells have high energy density compared with NiMH (and very high compared with SLA), but a pack of nine NiMH D cells isn't that much of a brick. Even if you use 12 D cells to get a voltage up around what the laptop expects from its AC adapter, you're still not talking a real boat anchor.
9Ah NiMH D cells are now available (see here), though they're not especially cheap. 4.5Ah D cells are rather better value per amp-hour. 7Ah 12V Chinese SLA batteries are, as mentioned above, the real value leaders, but they're not too fun to carry around.
Even a quite modest little $US30 pack of 12 1.8Ah NiMH AAs would give you around a quarter of the run time of the nine-cell Toshiba pack. That could be enough to get you to the end of your epic war movie, and the AAs would be useful for other things - they could just sit in a spring-terminal battery holder and be removed if you needed them for other purposes.
There are commercial external battery products for laptops, but all they basically are is an appropriately large string of NiMH cells (to match the voltage the laptop expects from its mains adapter) attached to a multi-plug cable to suit the laptop's AC adapter input, and bundled with a mains charger. It's eminently possible to make such a thing yourself (head off to your local radio control hobby place for pointers), but the result is likely to look like a bomb and make airport security people very excited, so it might be better to buy one of the commercial ones.
Anyway, a chunky external battery should give you at least a few more hours of run time. There's nothing you can do to the laptop's power consumption that'll make anything like that big a difference.
Regarding battery conditioning - yes, most of it is rubbish. The battery chargers built into laptops tend to be mystifyingly awful - all that computing power, and they can't include a dinky little chip to make sure the battery doesn't get barbecued if the laptop's always plugged into the mains. But battery conditioning won't help you with that. Generally speaking, cycling your battery is just going to wear it out quicker.
I wrote a column about this sort of thing a while ago.
Outdoor diodes
Will a full spectrum of LED lights give you the ability to see in color at night in low level light conditions?
What are the drawbacks of using LEDs for outdoor lighting?
Larry
Answer:
The Colour Rendering Index (CRI) of an RGB or other multi-colour LED array
won't be very high, because the LEDs output pretty narrow bands of wavelengths,
but it wouldn't be too bad. You could read a map just fine, for instance.
The Eternalight Rave'n and slicker
Rave'n 2 create strange multi-coloured shadows
when all four of their coloured LEDs are on at once, but you can see surprisingly
well by their light.
The problem with LEDs for general lighting purposes is that although prices are coming down for little LED bulb replacements, they're just not bright enough yet. Coloured LEDs achieve pretty good lumens per watt, but they aren't anywhere near white fluorescent tubes; white LEDs are only about as efficient as good incandescent bulbs, although their bluer, smoother light looks nicer.
Even if LEDs were as efficient as fluoros, you'd still need to spend a lot more money to get an LED array with the output of a standard 40 or 65 watt fluoro. 5mm LEDs are good for only about a tenth of a watt each; the much bigger "super-LEDs" still can't deliver much more than a watt each without heroic cooling. 40 one-watt Luxeon Stars won't cost you a lot less than $US400 retail. And, I remind you, at their current efficiency level you'd actually need more like a hundred white Stars to equal the output of a 40 watt fluoro tube. Maybe 70 Stars, if you use a mix of coloured ones.
Sure, the LEDs will last much longer, but this doesn't justify orders of magnitude more money.
For outdoor accent lighting - pathways, plants, sculptures, whatever - LEDs make more sense. If you want a low voltage light that you can cast into a block of epoxy, stick out in the rain somewhere and forget, LEDs are ideal, and their low output doesn't matter that much if you just want safety-light illumination levels, or a collimated spot on some relatively small feature.
LED Christmas lights are very popular now; they aren't very bright, but neither are incandescent Christmas lights (the coloured filters over the incandescent bulbs give them miserable efficiency...). The LEDs are efficient, naturally multi-coloured, will flash or flicker all day without damage, and will last functionally forever, barring mechanical trauma.
1956 all over again
I get black and white output from the S-video port of a Compaq Evo N1020V notebook computer running WinXP. The image on the TV is fine except that it is black and white. The image on the monitor is colour.
The video adapter is a Radeon IGP 340M with 32Mb memory.
I have used an S-video to RCA converter and plugged the RCA cable into a recent model Australian TV.
I have downloaded new drivers and they haven't fixed the problem
Steve
Answer:
You're probably outputting NTSC video to a PAL TV. That'll do that every
time; many PAL TVs are fine with a 60Hz signal, but only specifically NTSC-compatible
ones understand NTSC colour.
According to the troubleshooting manual (in PDF format here), the notebook defaults to NTSC video output. You change that in the Computer Setup menu, Compaq/HP's equivalent of the regular CMOS setup utility.
The "RCA converter", by the way, means you're sending the TV composite output. Most such converters for PC and laptop video adapters connect to a couple of extra pin-holes in the S-Video socket, which deliver a composite signal. Nothing's actually "converted".
Wet power
I have a 1400-1700 watt power inverter, and I live in rural New South Wales where temperatures soar. The problem I have with the inverter is that it often overheats when under load. I was thinking of using some form of total immersion cooling system and removing the housing of the inverter itself. The problem is that I have not been able to find a good non-conductive, non-corrosive coolant.
Matt
Answer:
If you're willing to take the thing apart, then I think just cutting a big
old hole in the housing and putting a monster fan on it would probably work
just as well. After all, even if you make yourself a mineral oil bath for
the inverter, you'll still have to move the heat to somewhere - maybe
a heat exchanger on the way to your hot water system, or something, but
probably just a radiator, cooled by the same kind of
big-ass fan.
Since the inverter's probably big enough that you could strap a car radiator fan to it, you might like to try that. If you've got a solar power system, then the times when the inverter's most likely to overheat are probably also going to be the times when you've got the most spare 12V to run a Fan Of Doom.
Ear-T phone home
I just found another lamp. It's from Germany but a little more usable than digital sundials!
The (German-language) Web site says it's got enough battery life for 7 hours of walking or 50 hours of reading, but that seems to be marketing "blah blah". They don't say anything about what kind of LED they are using.
Imagine all the geeks out there walking around with their Bluetooth headset on one ear and a lamp one the other. We will become Lobot!
Chris
Answer:
The Ohrlampe (Ear Lamp) looks like a neat little thing, but the three button
cells it uses aren't going to give you seven hours of respectable brightness.
50 hours before it's useless, I can just believe, but that's setting
the bar for "useless" very low.
The button cells they're using aren't minuscule - they've got about 75mAh capacity, which is a bit more than that of the CR2016 lithium coin cells that most key-ring lights use. It also runs from a stack of three cells rather than a stack of two, but that won't help its run time. More volts just means more current.
An LED running from tiny little button cells will be noticeably dimmer after only a few minutes of run time, and a small fraction of its initial brightness after an hour. You don't need much light for reading, of course, and the thing does only weigh about 15 grams.
Case hunting
I just wondered if you would know where I can buy a Raidmax Scorpio-668 case in Australia. Actually, I want two of them. I can't find a single place in Australia that sells them, and I've been looking everywhere. I've tried overseas stores like NewEgg; they either don't ship outside the States, or haven't got back to me.
Anyway, they're a great case, at a reasonable price unlike 90% of the other aluminium cases!
James
Answer:
I don't think Raidmax have a local distributor.
Buying cases from overseas is insane, of course; reasonably speedy shipping to Australia will probably cost you hundreds of dollars.
That Raidmax, however, is Yet Another Chieftec Product With A Different Badge, and there are a lot of other cases out there with similar features. Chieftec's basic case design is very recognisable, and sold under different names by lots of companies.
I reviewed a cheap aluminium Chieftec a while ago; you can still get a slightly facelifted version of it in Australia. No side window or garish front panel decorations, but basically the same thing as the Raidmax.
Aus PC Market (who sponsor me, but those wise in the ways of Dan will note that the links I'm using here are not the "adclick" ones that I get paid for...) stock a lot of cases these days, including a respectable collection of steel and aluminium Chieftecs and other reasonably cheap options. Check 'em out here.
The price of zoom
I have been wondering how much having a optical zoom lens on a digital camera affects the picture quality. In particular, the faults in the details that you see when you view parts of a 3-4 megapixel image at 100% on your monitor. I'm talking about the Kodak, Fujifilm, Nikon, Samsung etc. cameras that are be in the range of $AU600 to $AU1000 where you are, say 3-4 megapixels with 3X to 10X optical zoom. Does the fact that the lens is physically able to move (hopefully only in one direction but maybe a little in other directions too) cause picture detail to suffer at all?
As the consumer cameras at this price almost all have decent amounts of optical zoom, it's hard to know how much better the image might look if the optical zoom was not there.
I now have a funny feeling that this question was answered somewhere in that monstrous D60 review.
Matt
Answer:
Zoom lenses can have various faults, but it depends on the lens. No lens
is perfect; different lenses have different problems. Generally speaking,
the longer a zoom is the more distortion (edge bending, not just perspective
weirdness) the image will show as you approach one or both extremes of the
zoom range, but there's more to it than that. Different lenses have different
sharpness and contrast and susceptibility to
flare, and all of those
things can vary with the zoom setting and with the aperture.
You can tolerate nastier problems in lenses that're feeding lower resolution sensors; that's why camcorders often have monster optical zoom in a little teeny lens. Put the same lens on a 2000 by 1500 digital camera and it'd suck.
Fixing all of these problems is not trivial. There's a reason why you can spend $US6500 on a non-zoom telephoto lens for an SLR camera, yet only end up with about the same field of view as a $US400 10X-zoom digital camera that's zoomed in all the way.
Any lens that doesn't zoom is called a "prime" lens, and the prime-versus-zoom debate is an old one - exactly as old as zoom lenses, actually. Prime lenses can be smaller, lighter, and cheaper than zoom lenses, and optically superior, all at once - but the convenience of zoom is a huge selling point, and many zoom lenses these days are optically excellent. The quality difference between zoom and prime for most purposes can be trivially small.
Here's a good column on this subject.
Cat-o-vision
Can animals (especially cats) see progressive scan TVs better than interlaced TVs? Since I got my new Apex 43" HDTV, my cats seem to like to follow objects on the screen, whereas with my old TV they could care less (which isn't saying much, for a cat).
Should I leave the Animal Planet Channel on for them while I'm away?
Max
Answer:
I'm not sure, but I don't think the display's refresh rate or scan type
makes a big difference.
Cat vision and human vision are different in some significant ways (cats
don't seem to see colour nearly as well as we do, and when their pupils
are slits the world looks vertically compressed to them, but they can of
course see much better in low light), but I don't think it's the 50 or 60
field per second nature of ordinary interlaced TV that makes it so uninteresting
to many cats.
All cats aren't alike, though; I find it perfectly plausible that some cats could find HDTV interesting but standard definition TV boring. That might be because of the definition more than the refresh rate, though.
I've had a cat that not only tried to pounce on things on the TV screen (a nature documentary, naturally; if that caterpillar had been real and as big as it looked on the screen, it would have outweighed the cat), but then snuck into the TV cupboard and around the back of the set, possibly to see whether she could find a way in past the glass. That was with a plain old 50Hz PAL TV.
Cats often behave as if they can't see themselves in a mirror, after all, and that clearly has no frame rate or flicker issues, and even gives a 3D image. I think it's the lack of appropriate other stimuli - sound and smell - that cause many cats to ignore TV and computer screens, and mirrors too, at least after they're used to them. A friend's cat shot four feet straight up in the air the first time she was unexpectedly shown a mirror, but completely ignored them on all future encounters.
TVs may have sound as well as video, but the sound doesn't come from the image - it's near enough for blunt-sensed humans to be satisfied, but real predators are made of sterner stuff.
My current cat, I'm happy to say, has now grown out of hunting my mouse pointer.
Note that if your cats like the TV, you could get them a DVD!
Ain't nothin' people won't ask me
Reading your photography piece, with the Dr. Egon Spengler-esque forehead target photo at the top, I was reminded of a question I've always meant to ask.
What do you use in terms of hair maintenance?
Having a long, curly mop myself, I'm curious. Perhaps you have optimized hair care in a way I have not considered, maybe even overclocked your hair dryer?
Robert
Answer:
What do I use? Shampoo, every couple of days.
Actually it's more complex than that, thanks to my girlfriend who introduced me (well before the advent of the Queer Eye Crab People) to the concept of "product", and explained to me that any hair care substance that is advertised on TV is mass-market crap. This I found plausible, because the same rule certainly applies to PCs.
"Product", I can't stand, but I do now use fancy expensive Paul Mitchell shampoo and fancy expensive Paul Mitchell conditioner and sometimes fancy expensive leave-in conditioner as well, which makes me all curly and fabulous.
(Cue "I Feel Pretty".)
Frankly, though, I cannot detect any qualitative difference in the health of my hair (or scalp) now compared with my single days, when I washed my hair with soap and used cheap supermarket conditioner.
The expensive stuff smells and looks nicer, and you don't need to use as much of it, so it's not as expensive as it seems. It's still expensive, though. But what the heck.
My girlfriend now alleges that I'm not washing my hair the right way. The cat's all smooth and silky and never uses anything but spit, though, so I remain unconvinced.
And, in answer to your un-asked question: It's long because I can't be bothered getting it cut.
So I probably ought to have a beard as well, when you think about it.
In subsequent correspondence, Robert mentioned that for occasional use, mane and tail shampoo for horses is good for people-hair too. And other things.
OK. Stranger things have happened.
