Abstract: A self running type elevator system using linear motors in which a control of power supply to a plurality of elevator cars can be achieved without increasing the size of the system enormously. The system includes at least one travelling corridors, each of which is equipped with a primary coil of a linear motor; a plurality of elevator cars placed inside the travelling corridors, each of which is equipped with a secondary conductor of the linear motor; and a plurality of control device means, provided in correspondence to the elevator cars, for controlling a supply of a driving power to the primary coil at a position of the elevator car such that the elevator car is driven by a driving force produced between the primary coil and the secondary conductor of the linear motor by the driving power.

Abstract: In a voltage-source PWM step-up converter connected to an a.c. power supply through a reactor, even in the case where a reactor voltage drop V.sub.L changes in dependence upon a load current, it is required to compensate such a change to control a d.c. voltage so that it is equal to a predetermined value. Since this reactor voltage drop V.sub.L has a phase shift of substantially 90 degrees with respect to an a.c. power supply voltage, a control signal for compensating such a phase shift, resulting in the possibility that is exceeds above a linear control range of the control circuit to reach the saturation range. In view of this, in accordance with this invention, control signal means for compensating a reactor voltage drop V.sub.L is provided in the control circuit, thereby making it possible to perform a stable control to provide a stable d.c. output.