NSR Noise Suppressors - Wirewound Resistors

GENERATED NOISE IN IGNITION SYSTEMS High-frequency electromagnetic interference (EMI), commonly referred to as Radio Frequency Interference (RFI), generated by a gasoline engine ignition system, comes primarily from the high-voltage side of the circuit. Ignition systems produce sparks at the coil where the battery voltage is converted into high voltage pulses, at the distributor where the high voltage is channeled to the proper plug, and at the spark plug itself where the spark ignites the controlled burning of the gasoline/air fuel mixture in the combustion chamber (diesel engines compress fuel to ignite it in a process that produces negligible “noise”). These pulses have a very rapid current change (dI/dt) which generates an electromagnetic field around the ignition system. Electricity bounding through air causes ionization of some of the atoms in the molecules it passes through. When these atoms “de-ionize” they release a tremendous number of radio waves. The frequencies are random and come and go in fractions of a second, but almost every electronic device that is installed can be affected by them to some degree. These disturbances can disrupt engine and ABS control electronics and can interfere with radio and telephone communications. In communication systems, this interference sounds like a convention of crisps and crackles or as a rattle in radio receivers.