USB charging secrets

Everyone wants their mobile device to charge faster – but some of the things you’ll read (and sometimes even buy) do more to slow down charge speeds than anything else. There’s quite a bit of guff about the place when it comes to mobile device charging – and the best way to get informed is to understand just how USB charging works.
My story on USB Charging Secrets over at apcmag.com looks at the USB charging standards and helps you… Read more

How to calculate log2 without the real function

In computer science, being able to count in binary is pretty much a prerequisite. So too is being able to quickly work out the decimal range of a binary number by just knowing its length in bits. For example, an 8-bit number has 256 levels; a 10-bit number 1024; a 16-bit number 65536.
But working back the other way – this is, finding the number of bits based on the number of levels – is a bit harder. Calculators have a… Read more

The Internet of Things needs electrical engineers

I’ve said it for a while that as soon as a new generation of computers arrive, we should all be cheering – not because the new generation are that much better, but that the older generation become that much cheaper.
The reality is that each new generation of computers these days is only marginally better than the previous one – the days of booming gains are long behind us. That means lower prices are likely far more valuable than the performance/feature… Read more

Valves, not ‘vacuum tubes’: Australia’s rich tech heritage

Look at most textbooks on computer organisation and you’ll find a brief history of computing, usually starting with the era of ‘vacuum tubes’. These were the forerunner to transistors before the 1950s – any electrical signal that needed amplification (or rectification) was done using these devices.
But I have to admit the term ‘vacuum tube’ erks me a little, particularly when it comes from Australian university lecturers, and I felt the need to put things right at least from an… Read more

Converting base-10 fractions to any other base

Normally, converting numbers from one base to another only involves integers, but it can be done with with fractional numbers too – and using the opposite of the division-remainder method, called the multiplication-integer method. Here’s how it works:
Say, for example, you want to convert 0.8364 (base-10) to base-8. You start by multiplying the number by eight and note the integer. Take the fraction remaining and multiply that by eight, noting the integer, and so on until you either end… Read more