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When the lights go out...

Protecting your computer from unreliable power supply

how unreliable power affects your computer

Your computer, like any machine containing a microprocessor (VCR, microwave etc) relies on a particular level of electrical power.

If the power supply is not reliable (‘spikes’, ‘flickers’, ‘browns out’, ‘cuts out’ etc), then your CPU (Central Processing Unit) cannot do its job.

I once had the dubious experience of seeing someone who had just been through ‘electric shock therapy’ (ECT - electro-convulsive therapy).
Yes, it is still done to people, not just to computers.
This lady couldn’t remember her name, couldn’t stand up and couldn’t speak properly.

Your computer’s central processor can’t function, either, when instead of getting the level of electricity it uses to carry information (the level stated on the wall socket), it gets cut off (often with a ‘spike’), gets non-standard levels of power (‘flickers’, ‘brown-outs’) or sudden jolts of high-level electricity (‘spikes’).

Depending on the level of disruption, afterwards:

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What can I do?

I have no doubt that computer-users in the Riverland have a fair idea of what uninterrupted and efficient computer use means to them.

Those of us with laptops thanked God the compact and expensive piece of machinery wasn’t plugged into the ‘mains’ (gives a whole new meaning to ‘mainlining’, doesn’t it?), kissed the battery (carefully, on the outside) and kept on working for a couple of hours.

What you can do (apart from examining the contract between you and your electricity provider) starts with the ‘spike’ and goes as far as having your own backup electricity supply.

It depends on what you want.

  • I don’t want my computer equipment to be damaged.

    Then you need to make sure that your computer, and any peripherals (printer, 'Zip' drive, CD-drive, modem etc.) are always plugged into surge protection.

    A good quality surge-protector (and you can get them built into a plugboard) does not allow a damaging level of electricity to pass through.
    It contains a semi-conductor, which absorbs any dangerous levels of power, up to a point when it simply burns out (hopefully without damaging the equipment).
    When a surge-protector 'burns out', it leaves a gap that separates the power surge from your computer.
    Like a fuse, it has died in a good cause, protecting your equipment, and you then need to get another one.

    A low quality surge-protector is not a good deal.
    It may in fact just melt down into a bit of wiring, allowing anything and everything through to your equipment.

  • I want to be able to save my work, quit my programs, shut my computer down properly and turn it off, so no software or data can be lost or damaged.

    Then (in addition to surge protection) you need a UPS (Uninterruptable Power Supply).
    The UPS has a battery which stores energy while the power is on.

    If a power cut occurs, the UPS smoothly switches over to providing power off its battery.
    A basic UPS battery will give you enough time after the power cuts out to put everything away.

    A UPS can also protect you from irregular power, 'flicks' or 'brown-outs', where the power doesn't simply cut out, it goes up and down.
    The UPS, set up appropriately, can filter the power to your computer equipment, buffering the computer from the ups and downs of unreliable power supply, so the functional (working, non-damaging) level of current is maintained.

    You buy a UPS according to how many amps (ampères, A) of current it can handle and how long (in hours) its battery will last.
    UPS are rated in amp hours (Ah).

    For more information on Uninterruptable Power Supplies, check your requirements with your qualified computer technician, and then talk to a qualified electrician.

    A quick search at the Australian search engine, Anzwers, found the following websites in Australia which offer information about UPS:

    and others under Yahoo's Categories

  • I need to be able to keep on using my equipment, 24 hours a day.

    Then you need a standby generator (e.g. petrol-driven), at a rating which will support howevermuch equipment you want to run.

    This is not a small or simple job.
    You want guaranteed continuity of power supply, regardless of the behaviour of your contracted power supplier.

    And you want it in order to run very sensitive and delicate equipment.

    This means that you need to work out, with your qualified computer technician and qualified electrician, what kind of generator and UPS you would need set up, and how you would need them set up, so that:

    This article on protection against unreliable power supply also applies to any essential electrical equipment, some of which may not be as vulnerable to data-loss and damage as anything containing a microprocessor, but none of which is much use to us when the lights go out.

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