Position sensors for special effects in the big blockbuster cinema
A method for the sensorless determination of the rotor position is the "Inform" method developed by Prof. Schrödl. The Inform process has been used successfully for many years to identify the rotor angle of electric machines and has been further developed for the field of active magnetic bearings. It is based on the change of the magnetic properties as a function of the rotor position. By evaluating test pulses lasting only a few millionths of a second, the rotor position can be determined.