BOOT CAMP 089
CLEAN AND RELIABLE POWER
So, you think you are ready for the millennium? Your PC's
internal clock and operating system passed the Y2K 'roll-over' test, you've
purged all non-compliant software, downloaded the latest upgrades and patches
and laid on a stock of tinned food. January the 1st comes and goes
and your PC appears to be working normally, confidence is high and you're
halfway through saving a large and important file when 'phut', the mains cuts
It may have nothing to do with millennium 'bugs' in power
company computers. Electricity supplies can fail for any number of reasons, but
the chances of one happening will be even higher than usual during the first
few weeks of January next year, especially if we have a long hard winter. But
whatever the cause even a brief interruption lasting no more than a split
second can be enough to cause the files and data you are working on to be lost,
or worse! Important system files can be corrupted and you'll be left with an
The fact is we have become accustomed to a reliable mains
supply in this country. For most of us living in towns and cities blackouts and
'brownouts' have been a comparatively rare occurrence in recent years and this
has given us a false sense of security.
Power supply modules inside desktop PC have improved
enormously in the past few years and they can iron out minor variations in
mains voltage and even cope with small 'spikes' and surges lasting a few milliseconds
but a complete power loss can cause considerable damage. There is only one
solution – other than using a battery-powered laptop -- and that's a box of
tricks called an UPS or uninterruptible power supply.
A UPS connects between the mains socket and your PC. Inside
there's a re-chargeable battery, a battery charger and a circuit called an
inverter. Its job is to convert the low voltage DC from the battery into 240
volts AC. When the mains fails the UPS switches automatically to the battery
supply, maintaining the supply to the PC. Depending on the size of the battery
the backup power supply can last from a few minutes to an hour or more, which
should be long enough for you to save files close programs and carry out a safe
Broadly speaking there are two types of UPS, online and
standby. Online models operate all of the time by keeping the battery
constantly charged and supplying power to the inverter, which powers the PC. In
this case the battery acts as a buffer between the PC and the mains,
eliminating any irregularities in the mains voltage. Standby models kick in the
instant the supply fails, taking between 2 and 10 milliseconds to restore
power. The interruption is too brief to upset most modern PCs though it could
cause problems on some older models. Incidentally, standby UPS tend to be a
little cheaper than online types. Some more recent UPS designs are in effect
hybrids, using what's known as a double conversion process, which lightens the
load on the battery and provides a constant supply.
Most UPS modules are supplied with operating software that
flashes up an on-screen warning when the mains supply fails. Some programs will
carry out an automatic save and shut down routine for you, in case you are not
there to do it yourself. UPS management programs can also monitor the health of
the battery, indicating when it needs replacing (usually every two to three
years) and continually check the condition of the mains supply, logging trends
and predicting possible failures. Most models now have a 'hot-swap' facility
that allows the battery to be exchanged whilst the unit is operating.
Additionally all UPS devices filter and 'condition' the mains voltage, removing
potentially harmful spikes and surges, maintaining a steady smooth supply.
It all sounds terribly complicated and expensive but
surprisingly it's not. UPS units designed to protect stand-alone Windows
desktop PCs costs from as little £65, which is a very small sum to pay when you
consider how much your data, or even your computer is worth. UPS systems are
normally rated by capacity quoted as volt-amperes or 'VA' (see Jargon Filter).
The typical range is from 200 to 1500VA. Heavy-duty UPS systems for servers and
networks, fed from high-power circuits, go from 2000VA upwards. However for
most home PC users UPS modules in the range 200 to 500VA are usually more than
adequate, providing between 5 and 15 minutes worth of power, depending on the
PC, size of monitor and any peripherals.
Next week – chatting on the Internet
A large reduction in the mains supply voltage, causing
lights to dim and electronic devices like PCs to stop working
SPIKES, SURGES & TRANSIENTS
Brief increases in mains voltage, varying from a few volts
to several thousand volts, caused by lightning strikes, grid switching and
other devices connected to the supply
Volt-Ampere, a measure of electricity supply and generation.
You can work out the required capacity of a UPS by adding up the power
consumption figures (RMS values measured in watts) of your PC monitor etc, into
a VA figure by multiplying it by 1.414
Two tips for the price of one this week, especially for fans
of Outlook Express (version 4). The first is a way of disabling the opening
'splash' screen to make it open more or less instantaneously. It involves
editing the Registry so don't tinker with it, unless you know what you are
doing and accept the risk, and don't forget to make a backup first.
Close OE and start the Registry Editor by typing 'regedit'
in Run on the Start menu. Click on the plus sign next to HKEY_CURRENT_USER and
then drill down through the directory tree by clicking on the plus signs next
to Software, Microsoft and then double click on the Outlook Express folder.
Move the mouse pointer to an empty area in the right hand pane and right click.
Select New and then DWORD Value. Rename the icon that appears 'NoSplash',
(without the inverted commas), double click the icon and change the Numerical
value from 0 to 1. Close the Registry Editor and see OE fly!
Tip two is the hidden 'Easter Egg' in OE4. Don't get
excited, it's not very interesting but if you have a few minutes to waste click
on the Compose Message icon on the toolbar and on the Format drop-down menu
select Rich Text (HTML). Click into the message window then click into the Font
window and type 'athena', hit the Return key, close the window and choose 'No'
when asked if you want to save changes. Finally, click on the Outlook Express
icon at the top of the directory tree on the left hand side of the screen then
click once between Read Mail and Read News in the right pane and type 'about'
and watch what happens.