A travel surge protector is an electronic device that is plugged into a standard power source and provides power to other electrical devices, monitoring the level of power being supplied to those devices. If the voltage “surges” or “spikes” — that is, if the voltage exceeds a set amount — even if just for the smallest fraction of a second, a travel surge protector will either divert or absorb the excess voltage. Most surge protectors built are designed to be used in the home or office, and will provide many outlets for multiple devices to be plugged in, including standard electrical plugs, telephone jacks and USB connections. A travel surge protector, though, is generally smaller and lighter. It may employ a built-in swivel plug rather than a bulky power cable, and will usually provide fewer outlets of all sorts. Some travel surge protectors are designed exclusively for use in the United States, and others are combined with power converter units and can be used in countries where electrical standards, such as plug prong configurations, are different from American standards.
Surge protectors &emdash; also called “surge suppressors” &emdash; are crucial protective devices for electronic equipment like computers and their peripheral devices, as well as other sensitive electronic devices, because a voltage transient &emdash; the technical term for spikes and surges &emdash; will quickly overheat electronic devices' internal wires and connections, leading to costly or irreparable damage. Thus, surge protectors are designed to respond very quickly to voltage spikes, which last less than three nanoseconds (three billionths of a second), and surges, which last three nanoseconds or longer.
Travel surge protectors are useful travel accessories for those who intend to operate electronic equipment in areas where they're wary of the quality of the power supply, or where the potential exists for blackouts, brownouts, or outright power outages. When power is restored to normal levels after one of these events, the initial flow of current is often many times normal. In addition, damage to electronic equipment from voltage transients caused by lightning strikes can be avoided by the prudent use of a travel surge protector.
When a voltage transient occurs, a travel surge protector will generally operate much like an emergency pressure relief valve, diverting the excess power by creating a short-circuit and sending the excess current to the ground wire, while maintaining the flow of current at the proper level to the devices connected to the surge protector. Another method employed by some surge protectors is to store the excess power temporarily rather than divert it to the ground wire, putting the stored power to use gradually as the voltage transient subsides. Some surge protectors are also protected by fuses which will burn out if power levels get too high even after diversion of excess power.
Travel power surge protectors are rated by the independent product safety certification organization Underwriters Laboratories (UL). There are three UL-certified performance measurements of travel surge protectors consumers should be concerned with. The first of these is clamping voltage, the level of voltage required on a line before the surge protector activates. UL recognizes three levels of clamping voltage: 330 volts, 400 volts and 500 volts. The lower the clamping voltage, the greater the level of protection.
The next performance measurement of travel surge protectors is response time. Generally, a response time of one or two nanoseconds is preferable. The final performance measurement is energy absorption and dissipation; that is, the amount of energy the surge protector can absorb or divert before it fails and must be replaced. An acceptable level for a travel surge protector is 200 – 400 joules, although a good-quality home or office surge protector may be rated over 1000 joules. Because all surge protectors will fail after some point, some are manufactured with a light-emitting diode (LED) that is activated when the surge protector no longer can properly perform.