Control of the Automotive Electrical Environment

The increasing use of electronics in automotive control and in measurement and display functions requires an examination of the automotive electrical power supply characteristics. This environment is characterized by voltage fluctuations, noise, and severe transients. Mishandling and degradation of electrical components of the automotive power supply exaggerate these conditions. Electromagnetic interference arises from energy radiated from sources within and outside the vehicle.

This paper presents some measurements of these types of electrical disturbances on contemporary automobiles and discusses the effect of the phenomena on the performance of electronic equipment. Causes for temporary and permanent degradation of electronic equipment are investigated, and a systems approach to the problem is recommended. Attention is drawn to possible improvements to the electrical environment, directed to the source of the various disturbances, as opposed to the present method of dealing with the disturbances at the interface between the power supply and each electronic package.