* Posts by markp

3 posts • joined 12 Feb 2008

Thigh-drive phone charger put through its paces

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5 watts... pretty useful

I mean, in eco mode, my laptop is clocked at an average of about 9 watts (i have a proggie that measures battery discharge in mWh, and as a byproduct tells you the net power drain), and upto a little under 30w with every last possible gun blazing. This could be a nice topper-upper if, say, I was to travel somewhere and had it stashed in a backpack. Eight hours of walking around the city on & off, with the generated power also partially shared to phone, AA-trickle charger and mp3-cum-USBHDD could leave a nice two hours of photo backing up / uploading and the like without having to grovel to someone for use of their mains sockets or scrabble around in the murky, spider-infested depths behind the bunks in a hostel room.

Double them up and everything could get a guaranteed brimfull charge by the end of the day, and you'd get a tad more extra exercise into the bargain (maybe only 10% or so, but it's something).

Would it also work with cycling, to power the (white/red LED) lights without having to nob around with dynamos and stuff?

(Yeah, ok, my laptop is a low-drain ultraportable and was bought as such, so that it could both be used in a cramped train set (i measured; a 14" would be physically unusable on the birmingham commuter line, this 12" proved to be *just* usable), and so it could potentially last a workday of approx 50% use if I forgot/didn't have carrying space for/anywhere to plug in the charger, without needing a costly and cumbersome high-capacity battery (instead of it's 48Wh supplied compact one... now dipping below 30Wh after 2 years but still good for more than two hours off-charge). But, really, wouldn't that also be the machine of choice for a foot-travelling city rover, keeping the weight on their shoulders and bulk in their backpack to a minimum?)


Brit scientists brew up three-parent embryo



That's pretty cool...

the mad scientist in me wants to know if it's possible to do this with any other body cell, e.g. would any other cell with it's nucleus removed still be able to act as an egg if you put an egg nucleus into it, then fertilised it?

or conversely one egg with two fathers' sperm nuclei (filtered to get at least one X... though the mad scientist again wants to see if a YY embryo is viable and what happens if so).

The guy-whos-worked-in-a-hospital in me who's therefore seen all kind of developmental tragedy is ambivalent on it. It could be an awesome idea for fixing all manner of genetic ailments. But if it's not done well and things go wrong, there could be even more horrors in store.


French motorwonk savages hybrid cars


Citroen bashers, mileage, cycling, etc

Just a few random thoughts while i'm supposed to be job hunting, as well as other things.

Sorry if it gets a bit tl;dr. I have lots of stuff that gets piled up in the dark corners of my head.

People making crap Citroen jokes. Well done, you're peddling the same unfunny, ignorant twaddle that your peers have doled out for almost the last *seventy* years. About one of the most interesting, pioneering and innovative motor companies in the world. The Traction Avant, 2CV/Dyane, GS, A/B/CX, Xantia, C1, etc. Not always the largest, fastest or ultimately most powerful vehicles (I understand this is a disproportionately important thing for some people), but usually pretty decent cars and often ahead of their time.

Coming out of the showroom and only fit for scrap my ass. So long as you keep a handle on the frame rust, a 2CV will likely last forever. The GS is a solid classic. My dad had a series of Xantias, all of them excellent cars (particularly the turbodiesel, though that was unfortunately a short term company car), and the last one served him quite reliably for 10 years thru a period of financial hardship, eventually still selling for £500. Biggest problems being the cost of refreshing the auto-levelling suspension fluid and the slightly slushy auto box (far better than that of both the Volvo and Honda that replaced it, however). Though the styling of the C2 and C3 don't really thrill me, and the Berlingo is admittedly horrible to drive (being a non-turbo diesel mini van), I'd have any of their current passenger car range without a second thought.

And food for thought: The AX. I almost had one, except the terrible LHD-to-RHD conversion meant the pedals were arranged for someone twelve inches smaller than me - with three left legs. That and the notoriously nonexistant crash protection. Apart from that though, it was apparently an excellent little hatchback - quick, good handling, versatile, good looking, well equipped, and surprisingly efficient. The diesel version is in the guiness book of records following an UNMODIFIED one driving from London to Seville (1000 miles) on a SINGLE 10 gallon (UK) tank of standard diesel. Or, a certified MORE THAN 100mpg.

And that's for a car designed and built in the 80s, and quick enough to happily keep up with traffic and accelerate acceptably in-town and on the motorway (on paper at least, as quick as my first, more recently built, petrol powered car).

If only it had been better adapted for the UK market, and didn't have the passenger & rust protection of a tin can filled with broken glass, sulphuric acid and double-strength seawater, I'd have taken it and would probably still have it.

Hybrid mileage: the overall Prius mileage is indeed pretty shocking considering the low performance, size/shape of it and the amount of tech that went into it.

But it does apparently manage some incredible economy around town, which is really what it's meant to be - a Z/LEV electric city car that happens to have a nominally efficient conventional engine installed to allow it to travel *between* cities as well. Reports of getting 90 or even over 100mpg if you drive it sympathetically in-town, acclerating/cruising such as to not kick the petrol motor in until the battery is nearly drained, etc, whereupon it will run quite efficiently for just long enough to recharge them, then stop again. The petrol motor itself is probably very efficient for motorway cruising, but it has all that complicated drive system in the way between itself and the batteries, sapping performance and potential economy.

The hybrid concept is sound. People's distorted expectations for it, and some of the current implementations, are not. Hybridising a car will do very little for "highway" economy, as the ICE, particularly a medium-small one, is already running about as efficiently as it's able to in these situations (in fact, they're generally tuned for best possible economy along the continuum between typical motorway & A-road limits). It is, as I've said, in town where it helps, as modern, higher powered petrol engines are drastically less efficient in comparison below 25~40mph (depending)... one of the reasons why 20mph limits are dopey. (25s could work..). The effect is similar but more muted with diesels, as both their idle and strong-acceleration fuel consumption figures are lower, though still not as good as for cruising. The electric motor and batteries fill the gap by allowing the ICE to be halted at lower speeds (eg where you'd be in 2nd, maybe 3rd gear at best, and it'd just be chewing up fuel) and run off the electric motor that has different, more sympathetic speed/efficiency curves. In particular, an electric vehicle tends to consume LESS energy per mile as speed falls, as drag and friction becomes the main factor, rather than the baseline energy needed just to keep the suck-squeeze-bang-blow cycle going...

I've even considered hybridising my own, pretty inefficient mid-90s hatchback (by which I mean, typically 35mpg UK)... get a couple 1 or 2hp hub motors, overdrive them and connect to the rear wheels with enough battery power for a mile or two. Can then be used to inch the car forward in traffic queues or to maintain a low constant speed (10-15mph, if I'm lucky?) for short distances (I live in Birmingham - the traffic isn't typically THAT horrid door-to-door), and I can still pop the engine on for a minute every 4 or 5 minutes to either move it more quickly, or recharge the batteries direct (strengthened alternator).

On the subject also of using diesels for hybrids, the reputation of diesel cars etc: Well, I think the VW TDis have comprehensively revised the overal rep, but I have a personal example. My dad has a Fiat Panda Multijet. It's a great little thing. It's only 1248cc, but it has as much power (and more torque) as my 1600cc petrol-powered Astra, and manages to double the economy with about as much comfort, handling and interior room (save for the loss of a seatbelt/room for that crucial "half an adult" on the rear seat and a bag or two from the boot). Perfectly suitable for use with a hybrid as well - the cranking effort would indeed be a bit more, as it's higher compression, but it hasn't yet had any trouble starting in a second or two (plus another second for the small turbo to spool from scratch, if you're after instant high power). Not exactly excessive fire-up time. Its not the days of old Leyland diesel vans with a two-litre lump needing two minutes and most of the battery to get going and about 30bhp net.

The impressive thing is how it scales. The panda gets something like 70-75mpg on a good day. A friend of mine with a 2 litre Mondeo TDi still reports upto 65mpg, and he drives faster to boot. Not that a hybrid with a decent motor and control setup should need anything even as large as that for good performance. There's few opportunities on the open road not involving dragging loads over mountains where you'll ever be putting down over 60hp continuous for more than a minute or two (which will send you to a ton-plus terminal velocity in that time, on the flat), and I'd hope a hybrid system worth its salt could cover the deficit for a short period.

Anyhoo. Its not just the yanks with dibs on complaining about things being too far to reasonably cycle. Even living in a city suburb, my bike often lies fallow. There's places I can walk to happily, places I can take a train if I'm going to have a drink, nearby places where I tend to need to drive as I'm going to & fro quickly or carrying loads, and far away places where cycling is technically possible, but would be a considerable undertaking. Only a couple of jobs in my work history have I considered cycling - because my measured in-car door to door average road speed was 12mph or less - and only one I've tested it (and almost took up as it WAS faster, but then the weather turned awful for an extended period, and I can't do with turning up to work looking like I showered in my clothes and didn't towel off - or being killed because my tyres no longer have significant cornering grip, and my brakes need two or three moisture-purging seconds to respond). It's just not a viable thing any more, now I'm no longer a kid with all the things relevant to my life being within a 30 minute bike ride radius. I spent my first two years at university with a bike, and it was often quite handy.... but even in a town which measured all of 2x1 miles, there were enough things that demanded some kind of motorised transport - and the local bus service so dire - that the focus of my 2nd/3rd year summer break work was to "gather enough money to get ANYTHING with four wheels and an engine".

(And get it I did. VW Polo with a 45hp, 1.0L engine. Capable of 80+mph and nearly 40mpg with five large guys and a whole load of diving gear crammed into it. Basis of my theory that most modern cars are drastically overpowered, and they could be so much more efficient if things were made more sensible, as more powerful engines often = hungrier engines. It *almost* had enough power, compared to the astra which *just* has enough. The addition of a ~15hp leccy motor for accelerative bursts would have made it a truly excellent runabout).