PURPOSE: To make the removal easy and to increase the practical nature, by reducing the variance of power supply voltage accompanied with load variance and connecting the part between the power supply unit and the card unit with connector, in the electric control unit used for electric cars.
CONSTITUTION: The output of the transformer 2 of the power supply unit 1 is respectively rectified 3a...3c and output to the connector 9a via a part 4a-1, 4b-1, 4c-1 of the smoothing circuit. The output is fed to the connector 4b of the card unit 6 with the conductor 8 and fed to the constant voltage circuits 5a...5c via other parts 4a-2, 4b-2, 4c-2. The output of these constant voltage circuits is given to the card group 7. The circuits 4a-2...4c-2 and the circuits 5a...5c are located near the card group 7 being the load, the length of wirings between circuits is decreased and the impedance is reduced. Thus, the voltage variance accompanied with the load variance is reduced, the removal of the unit 6 is made easy by the use of connector, and the practicalibility can be improved.