IP Expo 2011 – what was fun

That’s IP Expo over with for another year. I’ve never quite get what the show is about, but it’s one I seriously consider attending. It’s lack of focus is probably what makes it intersting. I’ve always suspected that some exhibition organiser kept reading about IP and decided it was a buzzword lacking its own show and started one. Anything connected to an IP network is fair game, and these days this means almost everything.

The Violin memory box is an amazing piece of kit – a massive, high-performance thumb drive connected via fibre channel. They’ve done a lot of work basically striping data across flash modules which boosts performance, avoids hitting the same flash chip repetitively and gives redundancy – I believe they can lose six modules before it bites and its hot swappable.

There were quite a lot of other storage solutions on show, some interesting, some very much the same. One company is using ZFS, which is a technology I’ve had my eye on for some time.

Prize for the fund gadget is Pelco’s thermal imaging camera – at less than £2K for the low-res version it suddenly becomes affordable, and it certainly works well enough. Still on CCTV, someone had a monitor connected to a web cam and some software to identity faces. Spooky. This put a mug-shot of everyone looking at the camera down the side of the screen, recorded how long they were standing there and guessed their sex and age. It actually took ten years of most people, which helped with the feel-good but this technology obviously works and an obvious application is snooping on people looking at shop windows to work out what attracts the right kind of demographic (why else would they have developed it). I should point out that this was showing off the screen – the web-cam and face recognition was a crowd-puller

Another interesting bit of kit is an LG stand-alone vmware terminal. This basicall allows you to virtualise your PC and use them on a thin client. The implications of this for managability are obvious – keep your PC environment in a server room, where it can be cloned and configured at will, and leave a dumb-terminal in the front line. If the terminal breaks or is stolen – no problem whatsoever. The snag? Well the terminals aren’t cheap and they could do with toughened glass.


Kindle not on Fire

Amazon has just launched a Kindle for £89 in the UK, beating the price of its previous model by £20. It’s 30% lighter and 20% smaller too. This is no big deal: they’ve simply chopped off the alphanumeric keyboard and replaced it with a few buttons, removed the audio playback and cut the battery size in half.

I don’t think much of it. The original Kindle at £109 (£149 with 3G) looks well worth the extra.

In the US, Amazon has launched additional models: Kindle Fire and Kindle Touch. The Touch dispenses with all keys in favour of a touch screen. It comes with or without 3G and is clearly intended as the new standard model. The Kindle Fire isn’t a Kindle at all – it’s a 7” Android Tablet.

I’m not impressed. They’re using the Kindle brand to flog a fairly standard tablet. I’m sure it’s a fine Android tablet as Android tablets go, but a colour version of the Kindle e-book reader, it isn’t. It’ll rip through batteries at the same rate as every other tablet, and its colour screen will be just has hard to read in bright sunlight – the two problems overcome by the original Kindle’s e-paper display.

Comparing the Kindle Fire to the iPad2: well it’s half the price but lacks the cameras, and has only 8G of storage. It’s also Android rather than iOS (if that matters to you). And it’ll probably be about the same price using Amazon’s exchange rate; and a lot more expensive than other Android tablets already available.

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One distinguishing feature is the new Amazon browser – Silk. Whatever else it does, it’s designed to work with Amazon’s cloud servers to cache content and “speed things up”. Hmm. Sounds like Phrom’s notorious Webwise system all over again. Okay if you don’t mind Amazon data mining your web traffic.

Another strange feature is the pricing. The Touch and Fire aren’t available in England yet (the US launch is set for 15th November, no date for here). The US prices for all Kindles are substantially lower.  (Note that the original Kindle has been renamed the Kindle Keyboard).

England USA
Kindle Keyboard   £109 $99
Kindle Keyboard 3G   £149 $139
Kindle (buttons)   £89 $79
Kindle Touch   (£112) $99
Kindle Touch 3G   (£168) $149
Kindle Fire   (£224) $199

The figures in brackets are my calculation, using Amazon’s astonishing exchange rate of $1=89p.  All this talk in the UK media about these new models being cheap is overlooking this point.

It might explain why Amazon isn’t launching the Fire in England any time soon.

Update October 2012

The Kindle Fire is now available in England, from Tesco in fact, with a price tag of £130 including tax. At this price it’s a whole lot more interesting. Both the Kindle Touch and standard Kindle are £70, although the former is on “special offer”. The 3G versions are a lot more. It looks like I was right about the pricing <smug>


Electric Cool-box (or Esky) review

We’ve all seen them and wondered. Every gadget suppler has a small electric fridge or cool-box, usually supplied with a cable to run it off a 12V vehicle supply. I’ve even seen some very favourable reviews of these devices, from people with no credentials. Then, last week I needed to cool down various perishable foodstuffs whilst on a road trip, so I bought one. This is a review of this particular unit, but the principles will apply to the whole family of products.

I opted for the Halfords 8-litre cool-box, largely because I knew where to find a Halfords and I knew I’d seen cool-boxes there. I chose the 8L version because I knew the cooling principle they all utilise isn’t very energy efficient; I didn’t want to cool more space than I needed.

The Halfords 8L cool-box is certainly well-made and insulated. It’s very solid, with a hinged lid and catch that suggests quality. This is only to be expected; the Halfords models are not cheap.

Cable storage compartment in Halfords Coolbox
The cable storage compartment is a thoughtful touch

One nice feature of the 8L box is a fitting to hold it securely between two rear seats of a car using the lap belt, allowing it to double as an arm-rest. It’s also small enough to tuck away easily on one side of a boot. After fitting the supplied strap it’s also easy to carry and in another thoughtful touch there’s even a small compartment to store the power cable.

The power lead itself is long enough to reach from the dashboard to the boot without too much trouble and is fitted with a standard lighter plug on one end. The cool-box end of the lead has a proprietary connecting plug fitted, which might be tricky if a replacement is needed. Halfords do sell spare leads, but they’re not cheap!

Halfords 8L Coolbox
Coolbox (with test supply and thermometers)

Halfords also sells a mains adapter for something like £25 – ouch! This is one of the most expensive 12V adapters I’ve seen, but the cool-box is rated at 3A so you do need something a bit chunky. I decided against this purchase.

So far so good – the food was loaded into the cool-box and off we went with the cooler running while the engine was on. 3A is no problem for a car’s alternator but I didn’t want to drain the battery. The instructions also made it clear that running of the battery alone wasn’t a good idea.

However, at the end of the day’s driving, which amounted to several hours, it wasn’t at all clear that the inside of the box was any cooler than the outside. On our return I decided to test it properly to see what was going on.


These coolers all work using a thermoelectric effect. If you really want to know /how/ this works try looking up the Peltier or Seebeck effects in a good physics textbook. The short story is that if you take two plates made of different metals and place them together you can make a heat pump. As heat passes from the hot plate to the cold plate it generates a potential difference (voltage) between them. This is one of those electrical effects that works both ways, so if the plates are the same temperature and you pass a current across the plates they’ll drag heat from one plate to the other. In other words, is you pass a current through the two plates one gets hot by taking heat from the other, which gets cold.

This sounds very useful! All you need to do is place the plate that’s getting cold inside the box, and cool the plate that’s outside the box with a fan. This gives you a fridge with no moving parts apart from a fan, and as moving parts go, fan’s are a lot easier to manage than compressors and the associated plumbing for the coolant. Unfortunately there’s a snag – it’s not a particularly efficient process. Just how efficient it was in practice, I decided to find out.


Using a lab power supply and a several thermometers with remote probes to measure temperatures inside and outside the box I left the subject running while empty, after sealing down the lid. The inside and outside temperatures were recorded, with the inside being measured by the temperature of the plate.

Graph 1: temperature over time when empty
Graph 1 – Temperature over time (empty)

The manufactures claim that it can reduce the temperature of the contents by up to 20C compared to the outside. With the normal summer temperature tending to be 20-25C and a reasonable fridge temperature being 5-10C this would certainly be a suitable performance even allowing for a margin implied by the ‘up to’ preceding the actual figure stated.

The actual performance is shown in Graph 1. As you can see, after about an hour the temperature inside dropped from the ambient 22C outside to just 3C inside, where it stabilised; a drop of 19C. Pretty impressive! But remember the 3A current drain – it turns out it needs 3A constantly so you definitely can’t run this without taking power off the engine. Sill, once cooled it should stay cool for a reasonable period, right? Actually, wrong. Take a look at Graph 2.

After disconnecting the power it returned to room temperature in about 20 minutes. Very disappointing!

Graph 2 – Temperature restored when empty

However, this isn’t really a good test, is it? Who needs to cool down a empty box – you really need to cool the contents, and what matters is how long the contents then stay cool once the power is removed. To test this I chose to use 1.5L of water in a sealed plastic box as the payload.

Test payload in Halfords Coolbox

This choice was largely governed by the sealed plastic boxes I had available. There wasn’t space for 2L of water, so 1.5L was a compromise to make calculations easer – and besides, 1.5L or 1.5Kg of food is a reasonable payload for an 8L box. The results can be seen in Graph 3 below.

Graph 3 – Cooling effect when full

As you can see, after a full hour the temperature had only fallen by 3C – not much good to anyone. I decided to keep the experiment running for a further eight hours, during which the payload’s temperature eventually stabilised at 10C below ambient. The graph shows the measured temperature a bit lower, but by this stage the outside temperature had also dropped, so it was 10C less.

This isn’t really much good for cooling food down; even after running it all day it’s unable to reach ‘refrigerator’ temperature; your food wouldn’t last long. The only useful thing you can do with it is put pre-cooled items in it and hope they stay that way due to the insulation, because even with the power full on it’s only going to stabilise at about 10C . Graph 4 shows what happened.

Graph 4 – Warming up when full

As you can see, thanks to the insulation of the box it does at least manage to keep its contents cool. The tests were carried out away from the wind and sun – ideal conditions, but only sensible.


This is a nicely made piece of equipment, but its real-world performance makes it completely unsuitable for its intended purpose. The best you can say is that if you place cold items in it, it’ll keep them cool as long as you keep it supplied with a lot of power. If you don’t use the electric cooler it’ll work almost as well thanks to its insulated construction.

If you are looking for a workable solution to the problem, and insulated box and a block of ice will easily out-perform this arrangement, at far lower purchase and running costs. The low-tech conventional cool-box (Esky) and freezer pack still has a lot going for it. Don’t waste your money on one of these.

Halfords refunded my money very quickly.