Trinamic Motion Control Gmbh & Co. Kg

Maxim Integrated Products, Inc.

Lars Larsson

Bernhard Dwersteg

Onno Martens

Christof Heilemann

A solenoid system and method can include: providing an energizing voltage to a coil of a solenoid; providing an AC signal superimposed onto the energizing voltage; detecting current through the coil including an AC current amplitude induced by the AC signal and including a DC offset current amplitude; determining the AC current amplitude is a low AC current amplitude based on an armature within the solenoid being in a retracted position or determining the AC current amplitude is a high AC current amplitude based on the armature being in an extended position with the control logic, and where the AC current amplitude is determined utilizing the AC signal for synchronous demodulation; and determining a temperature fault based on the DC offset current amplitude falling below a DC offset current amplitude threshold.

Solenoid system with position and temperature detection

A method and a circuit assembly for driving a 2-, 3- or more phase stepper motor by predetermined courses of current curves, especially for a microstep operation, is disclosed. For minimizing the memory capacity needed for storing supporting points of the course of the current curve by which the microsteps are realized, the course of the current curve is divided into a number of segments to which each a basic or main gradient between adjacent supporting points is assigned, so that for each of the supporting points only a deviation of the gradient at this supporting point from the related basic or main gradient has to be stored.

Method and circuit assembly for driving a stepper motor

A method and a circuit arrangement are provided in which a mechanical load applied to the motor shaft or a load angle of the motor can be detected without sensors in a stepper motor. This is achieved substantially based on the fact that the load or the load angle creates a mutually induced voltage (back EMF) in the motor coils and the load or the load angle is detected by determining the phase shift of the motor voltage at at least one of the motor coil relative to the coil current at said motor coil connection, the phase shift being caused by the mutually induced voltage. A method and a circuit arrangement are also provided wherein the motor current of a stepper motor can be controlled according to load angle in such a way that the current consumption of the motor is relatively low.

Method and circuit arrangement for detecting motor load without sensors and for controlling motor current according to load for a stepper motor

A method and circuit assembly are provided for controlling the motor current in an electric 3-phase motor, in particular in a 3-phase stepper motor, by a chopper process. For at least two of the three motor connections a respective chopper phase is cyclically activated, while a target motor current supplied for the motor connection in question is injected into the motor connection by a chopper process, while the two other motor connections are connected to each other.

Method and circuit assembly for current control in 3-phase motors

A method and a circuit arrangement are provided which enable a mechanical load applied to the motor shaft of a stepper motor (M) or a load angle of the stepper motor to be detected in a sensorless manner. A method and circuit arrangement are also provided which enable the motor current(s) of a stepper motor to be controlled in accordance with the load value such that the load angle is as high as possible without risking step losses, in order to maintain the current consumption of the motor as low as possible. This is achieved according by evaluating the temporal duration of the ON- and the FD-phases during the chopper control of the motor.

Method and circuit arrangement for sensorless engine load detection and for controlling the motor current in accordance with the load value in stepper motors

A method and a circuit are provided for the commutation of brushless direct-current motors (BLDC motors), without using sensors, and especially to a method and a circuit for producing rotor position signals, without using sensors, for the commutation of brushless direct-current motors. In the method and the circuit Hall sensor signals are emulated without sensors and rotor position signals free of disturbing pulses and with a correct phase position are generated from said signals. The rotor position signals can be used to carry out a reliable, sensor-free commutation.

Method and circuit for producing rotor position signals and for the commutation of brushless direct-current motors, without using sensors

A method and a circuit arrangement for operating stepper motors or other appropriately dimensioned synchronous motors is disclosed in which between a first operational mode for normal motor operation and a second operational mode for detecting an operating state of the motor like for example its load can be switched. The method and the circuit arrangement is especially provided for determining a reference position of the motor without sensors by driving the motor against a mechanical stop wherein an increase of the load which is caused by this, is detected as a change of the operating state (FIG.).

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Hamburg, Germany

Lars Larsson