Abstract: A control system for an electric car includes a motor connected to a battery as a main power source for driving the electric car, a strong electricity unit having high voltage devices including an inverter for driving the motor based on power supplied thereto from the battery, a weak electricity unit having low voltage circuits including a microcomputer for data processing, and connection devices for connecting the strong and weak electricity units in such a relationship that a signal path is connected between the units as electrically isolated therefrom, wherein signal transmission between the strong and weak electricity units is carried out with use of the signals isolated between the units.

Abstract: A catalyst heating control device for cleaning automotive engine exhaust gases, comprising a generator, at least one battery, a catalyst heating control apparatus, a battery charging device and an electronic fuel injector. Before starting the engine, the catalyst is preheated. At the start of the engine, the catalyst preheat control is curtailed according to the state of the batteries. The catalyst current control is performed by detecting the catalyst activation temperature. The catalyst is heated usually to about 350.degree. C., at which point the current supply for heating is terminated.