The Common-core Filter as an Electromagnetic Interference-suppression Device

Abstract

Though everyone is daily made aware of the existence of electromagnetic interference (as when one drives an automobile near a faulty neon sign and hears a loud “buzz” on the car radio, or when one uses a television receiver while an electric mixer is running nearby and the interference from that appliance obliterates the picture) it is not the most frequently cited form of pollution. However, radio communication services are expanding at a rapid rate, receivers are becoming more sensitive, and we are moving toward more complex types of communication. Because of these factors and the accelerated growth in the use of electrical appliances both at home and in industry, there is an ever-increasing effort to control electromagnetic interference caused by electrical equipment. Some nations, in fact, have promulgated laws to control electromagnetic interference. As industry responds to the need, undoubtedly more and more electrical equipment will have built-in powerline filters and other noise-suppression devices to prevent interference. The problem, however, is not merely one of the cost of adding a powerline filter, but that the addition of a filter may also affect the safety and performance of a machine.