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Power Supply Concerns

There are five types of power supply variations which can affect your computer:

  • supply failure (black-out)
  • supply reduction (brown-out)
  • spikes
  • voltage fluctuations
  • mains noise

The first two are usually caused by some fault with the mains electricity supplier's equipment. The only way to protect from supply failure is to use some form of back-up or uninterruptible power supply (UPS) - these tend to perform all the functions necessary to cope with any of the other types of fault.

Supply reduction means a brief (a few seconds or less) but substantial reduction in the supply voltage, not to zero but to a significantly low level (say below 75%). Most computers can cope with a degree of brown-out and this may be specified in the manufacturer's instructions.

Spikes can be caused by lightning strikes or by sudden changes in load on your local supply. Nearby buildings or rooms may use heavy electrical machinery or there may be mains circuit switching equipment in your area. The simplest solution to this is to use a surge protector - a device that sits between the mains and the computer's power supply and evens out spikes and surges in the mains power.

Power supply problems may not be noticeable in many cases since the power supply will attempt to cope with situations such as a supply reduction. More serious problems may cause the power supply to trip-out or automatically switch off.

Spikes and surges could damage the power supply or some of the components in the computer system such as the hard disk.

Next: SAQ on Power