A power dip is a very short drop in voltage in a system (generally home AC wiring). It is most commonly observed when a high-current device (such as a hair dryer, microwave, or table saw) is switched on and lights in the same system will dim momentarily. There are also other sources for voltage dips coming from places higher up in the distribution stream than an individual home.

While most electrical devices are not adversely effected, devices that need a more reliable voltage can be protected with the use of an uninterruptible power supply

Uninterruptible power supply

An uninterruptible power supply, also uninterruptible power source, UPS or battery/flywheel backup, is an electrical apparatus that provides emergency power to a load when the input power source, typically mains power, fails...

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