In switching power circuits, due to the rapid switching of high current and high voltage, interference emission is created a serious problem. With the increase in switching frequency, possibility of interference also increases. When the interference is strong enough, then it can affect the normal working of associated circuits also. Electric and magnetic fields exist in any operating electric circuit. The current flowing in the circuit generates a magnetic field. For such a current to flow,

more »

... e must be a potential difference, which produces an electric field. These fields can exist in any substance, including a vacuum. If they are strong enough, they make it possible for one electrical device to affect another. When this occurs unintentionally, it is known as electromagnetic interference, commonly abbreviated as EMI and often simply called as 'noise'.