Robert Boschgmbh

Dirk Lamprecht

Reinhard Neul

Hartmut Seiler

Ulrich Vollmer

Markus Weber

Torsten Henke

Oliver Wackerl

Stefan Walz

Panagiotis Kosioris

Sylvia Wiedemann

Alexander Krautstrunk

Andreas Speinle

A switch device for an electric motor includes at least one half-bridge having two semiconductor switches to energize at least one phase of the electric motor on demand. The switch device further includes a drive device assigned to the semiconductor switches and configured to actuate the semiconductor switches in accordance with an activation signal. The driver device includes an oscillator to generate an operating clock frequency, an apparatus to receive a synchronization signal, and a device to adjust the operating clock frequency in accordance with the synchronization signal.

Switch device for an electric motor, control device and steering system

The invention relates to a method for determining the phase currents through phase windings () and an excitation current through an excitation winding () of an electrical machine (), wherein an excitation winding () is connected between a star point () of the phase windings () and a defined reference potential, the method comprising the following steps: &#x2014;periodic driving of the electrical machine () with a predefined pulse pattern (); &#x2014;determining a respective measurement current (I) in a plurality of temporal measuring windows () of a measuring period (), wherein the measurement currents (I) correspond to currents through one of the phase windings () and through one or more parallel connections of a plurality of the phase windings (); and &#x2014;determining the phase currents and the excitation current by evaluating the measurement currents (I) determined during the measuring period ().

Method and device for determining phase currents and an excitation current of an electrical machine, and motor system

The invention relates to an electronically commutated electric motor. The electric motor comprises a stator, and a rotor, in particular a permanent-magnetic rotor. The electric motor further comprises a control unit connected to the stator. The control unit is designed to actuate the stator such that the stator can generate a magnetic rotating field for rotationally moving the rotor. According to the invention, the control unit of the electric motor is provided with a power output stage having semiconductor switches. Subject to the low-resistance, or short-circuited, semiconductor switch of the power output stage, in particular as a result of defect, the control unit is designed to actuate the stator for generating the rotating field such that during a complete rotor revolution, the rotor can provide a mechanical output, or in the operational mode, a braking torque of the electric motor caused by the defect is reduced, or completely neutralized, by the low-resistance, or short-circuited, semiconductor switch.

Electronically commutated electric motor having emergency running properties

A method and circuit arrangement for determining position of the rotor of an electronically commutated motor, wherein the rotor has magnetic axes having different permeances. Voltage is applied to stator phases, and resultant phase currents are monitored for purpose of determining rotor position in the standstill state of the motor. First and second rise times of phase currents are determined until predetermined limit values are reached in unsaturated state. The assignment of a magnetic axis to a stator phase is determined from first rise times of the currents in unsaturated state of the rotor core, and the polarization of the rotor is determined from second rise times of currents upon energization with saturation effects. After run-up of the motor, initial energization of the stator can be determined comparing levels of the magnet wheel voltages and corrected by changing the commutation of stator energization.

Method and circuit arrangement for determining the rotor position of an EC motor in the standstill state

In an electric power tool and a method for operating an electric power tool, a torque limitation of an electric motor reacts when a load moment exceeds a predetermined threshold and in which an output request is carried out by means of a switch. A supply of current to the motor is interrupted when a criterion for the reaction of the torque limitation is detected based on a speed detection of the motor.

Electric power tool and method for operating same

A device for determining a rotation rate can be employed in conjunction with a rotation rate sensor which furnishes one or two output signals that among other things are a measure for the Coriolis acceleration and thus also for the rotation rate. The device includes an arrangement for signal processing, with which both digital subtraction of the output signals and an ensuing digital multiplication by a carrier signal shifted in a digital phase shifter are accomplished. The digital multiplication is followed by a digital/analog conversion and low-pass filtration, which in the final analysis furnishes an output signal (DR) that is equivalent to the rotation rate.

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Stuttgart-Rohr, Germany

Dirk Lamprecht