Surge is instant high voltage, this high voltage ranges from hundreds of volts (amps) to thousands of volts (amps) or higher, the duration ranges from one thousandth seconds to one hundred millionth seconds, which is a great potential dangerous in equipment, it may cause the data loss or shorten the life of the electronic components ,what's the worse ,it may also damage the equipment or other serious results. Therefore, there are many electronic devices equipped with a surge suppressor to protect equipment and users. There are two phenomena generated surge, firstly, produced by nature, such as lightning strikes; secondly, the load enter the electronic equipment instantly.