Siemens Aktiengesellschaft

Ingemar Neuffer

Felix Blaschke

Norbert Becker

Karl-Heinz Bayer

Christian Keller

Albert Mueller

Wolfgang Michel

A method for controlling the run-up of a conveyor belt BY increasing a setpoint value of the belt's speed with an increasing acceleration in a first time interval, and with a decreasing acceleration in a second time interval, thereafter plotting a curve of the increasing acceleration against time which has a positive curvature in the second interval, a second time derivative of the acceleration in the first and the second time interval is at least approximately constant and at least approximately equal and opposite.

Method for controlling the run-up of a conveyor belt and drive device for a conveyor belt

A first acceleration reference value is continuously determined by a nonlinear distance control. In parallel thereto, a second acceleration value is generated by a nonlinear velocity controller. A simple selection criterion that comprises only these two alternative acceleration values engages the second alternative acceleration reference value engagement for run up. The first alternative acceleration reference value initiates the destination braking. The second alternative reference value is used for approaching the destination position. The trip destination and the velocity of the positioning drive can be accommodate inching velocities.

Method and apparatus for the distance control of a positioning drive

Exactly defined current pulses having high edge steepness and high final value are required for the pulse-like generation of high magnetic fields in inductive users. Particularly in nuclear magnetic resonance tomography, such pulses serve the purpose of building up a topically variable magnetic field with an optimally linear field strength gradient. A power supply for generating such current pulses includes a series connection of a stepping voltage switch and a variable voltage source, whose resultant output voltage is applied to the inductive by a voltage commutator user with a suitable operational sign for the build-up or dismantling of the individual pulses. A switching and regulating circuit controls the stepping switch, the variable voltage source and the voltage commutator dependent on prescribed rated curves of the pulses, such that the pulses have a rise and decay time independent of the final value.

Power supply for an inductive user, particularly a gradient coil

A vector analyzer which serves for determining defining quantities of a planar vector in which the output of a digital counter is fed, via sine and cosine function generators, to a vector rotator addressed by the component voltages of an input vector and made to follow the value of the phase angle of the input vector by means of a three point control in order to make the output of the digital overflow counter follow the phase angle of an input vector by means of a control loop; the counter content is reset to zero without problem if the value 360.degree. of the phase angle is exceeded. The invention can be used particularly for field orientation control of rotating field machines.

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Erlangen, Germany

Ingemar Neuffer