An electric motor control unit mounted in an automotive vehicle having a motor
that is variable in its rotational speed. A temperature sensing element is arranged
to contact a busbar so that relays permit switching operation in response to detection
of abnormal heat generation. This controls an electrical power supply to the motor
to decrease the rotational speed of the motor without complete stopping of the
motor. The rotational speed of the motor returns to a normal speed from the decreased
speed by switching operation of the relays with diminishing of the abnormal heat generation.
