A rotor includes a rotor core; and first permanent magnets and second permanent magnets arranged in the rotor core so that, on a cross-sectional plane of the rotor core perpendicular to the rotation axis thereof, the first and second magnets corresponding ...

A boom positioning device for high-position working, capable of ensuring a desired positional accuracy even in positioning a work location at the tip end of a boom from a distant place, the device comprising an imaging means (4) having a multi-axis driving...

The invention prevents a voltage change dv/dt of an inverter from directly causing an erroneous firing of a semiconductor brake switch, which may short-circuit the inverter during operation. To brake a motor (10) driven by an inverter which consists of a t...