·EMI
The EMI is the abbreviation of Electro-Magnetic Interference. This electromagnetic interference usually interferes other electronic equipment by power circuit or cord. It can even affect the data transmission. In addition, there are a lot of noise that can be received by electronic equipment antenna (such as: household radio antenna, etc.), and changed into EMI. In order to solve the electromagnetic interference, the input and output terminal of many electronic devices have filter circuits which can avoid being interfered or interfere other equipment.