Engineer gadgets

Pass me the 230-amp USB charging cable, please…

The BBC has an article about a mobile phone battery that will charge from empty to full in 30 seconds.

The technology behind the brand new battery is of course exciting. Lithium polymer batteries have their drawbacks and I should imagine a battery that can be charged rapidly will be of even more interest to manufacturers of electric cars and renewable generators than mobile phone manufacturers.

But since Israeli start-up StoreDot chose a mobile phone to demonstrate their technology then I have to ask where the 230-amp USB charging cable is going to come from.

The faster a phone charges, the more current it requires. And to provide more current the power source needs to be more robust (typically larger) and the connecting cables need to be larger to carry the current safely without overheating.

Since it has become standard to use a 5-volt supply to charge a mobile phone I thought I’d work out how much current would be required to charge a typical phone battery in 30 seconds.

250-amp cables
250-amp cables

The answer is a whopping 230 amps, based on a 3.7 volt 2,600 mAh battery capacity like the one inside Samsung’s Galaxy S4 mentioned in the article.

In case you’re wondering how fat 230-amp cables are, you’re talking  typical jump lead size.

In practical terms phone chargers would need to seriously increase the voltage to charge a phone that quickly, but they are unlikely to go much above 25 volts due to the increased risk of electric shock.

Even at 25 volts the current required would be over 45 amps.

Bad Stuff End User nuisance calls and messages

Nuisance Ministers on Nuisance Calls

Forgive me but I don’t hold the Department of Culture, Media and Sport (DCMS) in very high regard when it comes to technology issues. It’s a very personal thing, dating back to the Digital Economy Act, their blinkered approach and refusal to listen to anyone who wasn’t an ageing rock star (or paid by an ageing rock star).

Culture Secretary Maria Miller trumpeted something over the weekend that, according to the substantial press coverage at least, should reduce the current high volume of unwanted marketing and other nuisance calls.

I’m confident the plans announced will do very little to reduce the deluge I currently get.

Why? Because spammers have shown themselves time and time again to give not a toss about rules and regulations.

For example, I signed up to the Telephone Preference Service (TPS) years ago, and have recently re-added my numbers just in case. Little help it does.

To understand why one has to look at the economics.  TPS is a for-profit money making service run by the Direct Marketing Association (DMA).

The DMA charge to query its database – around £2,200 per annum, plus VAT. So from the start there is a disincentive for Joe Bloggs Marketing Co Ltd to use it. Better subcontract the calling overseas, with a paper requirement to check TPS and full deniability if their agents get busted calling my housebound, blind and painfully immobile 98-year-old grandmother an hour after she goes to bed of an evening.

The Solution

Is painfully simple. Put a legal requirement on on Telephone Service Providers (TSPs) via the forthcoming legislative overhaul of the Communications Bill to provide, free of charge, effective call blocking tools.

You see, TSPs like BT, Virgin Media, Sky and the rest actually make money from nuisance calls through so-called termination charges. They get paid for putting the nuisance call through to you, so there is little real incentive for anyone in the industry to tackle the problem.

Subscribers like you and I can pay, around £5 per month (£60 per year) for the privilege of having nuisance calls blocked at the exchange – but I see that as blackmail; I pay enough already to rent a phone line. My service provider is making money from the misery of a nation by accepting termination charges from marketeers who hound me 12 hours a day.

Now, if every telephone service provider was obliged through their operator’s license to provide a free and effective nuisance call blocking service then it would be a different story.

Exchange-level blocking is far more powerful than the little black boxes one can buy to filter calls before they hit your handset.

For example, if the call originates in the UK, even if the caller withholds their number, the exchange still knows the ID of the originating caller.

BT therefore, if you pay them for the privilege, provide a blocking service that allows users to dial a special code immediately after a “number withheld” call to block further calls from that number, without affecting calls from your local doctor’s surgery, who happens to withhold their number when calling me.

By the way, what I said above about spammers ignoring rules and regulations, a rule prevents a marketing company calling you withholding their number. Yet this goes on day in, day out.

So a legal obligation on all telephone service providers to provide free blocking tools like the one I described from BT. We’ll all use it if it’s free, and marketeers will have to find a new way to inflict their pain.

After all the current Government, as per the DCMS, is a big fan of free blocking (switched on by default) when it comes to web pornography and the like.

But Miller and Co at the DCMS are probably too busy slapping themselves on the back for the positive press over the weekend to listen to my advice. After all, a DCMS minister openly ignored my advice after inviting me to give it face to face.

James Firth

Engineer servers

Is this a symptom of the recession or has the Moore’s Effect plateaued?

Moore’s Law predicts that advances in device fabrication double the number of transistors possible on any given piece of silicon approximately every two years.

This has lead to a constant performance increase in computing over the last 40 years. That is, a near-linear improvement in CPU speed and storage capacity.

It has also lead to another notable effect – a rapid depreciation in the cost of new hardware over the first couple of years after a device first goes on sale.

For example I built a server in 2005. Within 2 years the price I paid for the motherboard, CPU and RAM had collapsed to less than half what I paid initially. In fact it allowed me to upgrade the CPU, RAM and hard disks to give a vast performance increase for less than I paid for the original components.

Fast forward 5 more years to early summer 2012 when I built my last server. 18 months later the CPU and motherboard are still on sale. But the i7 3820 CPU is today exactly the same price I paid for it and the X79 chipset motherboard has actually increased in value, from just under £200 to over £260.

Even the Ripjaws 16GB quad-channel memory kit I bought has gone up 20 quid, something quite unusual after years of tumbling memory prices.

In fact the only notable depreciation is in the cost of enterprise-class hard disk storage, due to a couple of high performance 4TB disks entering the market in the intervening period.  So I might just be able to afford to upgrade from 2TB to 4TB RAID-1.

Of course this could just be a temporary blip due to a combination of the severe economic down turn we’re [hopefully] heading out of and the rapid decline of the desktop computer reducing the demand for traditional motherboards and leading to a temporary glut in the market in 2012.

However it could be an economic indicator that the Moore’s Effect is plateauing, meaning computer hardware will hold its value for longer and I’m denied the cheap performance boost I’d grown used to 2 years after I build a server.