An adjusting device having a DC motor and an adjusting member driven by an output shaft of the DC motor is disclosed. The adjusting device has a power driver coupled to the DC motor for controlling a motor current of the DC motor, a current measurement circuit that is adapted to detect a current consumption of the DC motor and to output a current measurement signal dependent on the number of revolutions of the DC motor, and a computing unit, to which the current measurement signal is input adapted to determine the number of revolutions of the DC motor based on the current measurement signal.

An axial brushless DC motor comprising a stator including a plurality of coils, a rotor including a magnet with a plurality of pairs of magnetic poles and adapted for movement relative to the stator in one or more full steps, and a coil phase circuit adapted for moving the rotor relative to the stator a fractional step less than the one or more full steps and/or holding the rotor at the fractional or one or more full steps.

According to one embodiment, there is provided a control device including a drive circuit and a control circuit. The drive circuit includes a plurality of transistors and a current determination circuit. The plurality of transistors is electrically connected in parallel to each other between a first node and a second node. The first node is connected to a power supply circuit. The second node is connected to a DC motor. The current determination circuit determines a current flowing between the first node and the second node. The control circuit generates a control signal to control a number of transistors to be turned on among the plurality of transistors in accordance with the determined current. The drive circuit drives the DC motor using a current in response to the control signal.

Methods of compensating for play and for initializing a position encoder in an actuation system (2) including an actuated system (8) comprising an elastic element, and an actuator (4) with a stepper motor (12) having at least one electrical phase.

Methods of compensating for play and for initializing a position encoder in an actuation system (2) including an actuated system (8) comprising an elastic element, and an actuator (4) with a stepper motor (12) having at least one electrical phase.

According to one embodiment, there is provided a control device including a drive circuit and a control circuit. The drive circuit includes a plurality of transistors and a current determination circuit. The plurality of transistors is electrically connected in parallel to each other between a first node and a second node. The first node is connected to a power supply circuit. The second node is connected to a DC motor. The current determination circuit determines a current flowing between the first node and the second node. The control circuit generates a control signal to control a number of transistors to be turned on among the plurality of transistors in accordance with the determined current. The drive circuit drives the DC motor using a current in response to the control signal.

An axial brushless DC motor comprising a stator including a plurality of coils, a rotor including a magnet with a plurality of pairs of magnetic poles and adapted for movement relative to the stator in one or more full steps, and a coil phase circuit adapted for moving the rotor relative to the stator a fractional step less than the one or more full steps and/or holding the rotor at the fractional or one or more full steps.

An axial brushless DC motor comprising a stator including a plurality of coils, a rotor including a magnet with a plurality of pairs of magnetic poles and adapted for movement relative to the stator in one or more full steps, and a coil phase circuit adapted for moving the rotor relative to the stator a fractional step less than the one or more full steps and/or holding the rotor at the fractional or one or more full steps.

In one implementation, a motor module according to the present invention includes: a motor driving circuit 10 to drive a motor M; and a position estimation device 30 to output an estimated position signal of a rotor R of the motor M. It also includes: a motor control circuit 20 to supply a command voltage value to the motor driving circuit 10 in response to a pulse signal; and a variable step-size memory 40 storing variable step-size information, which defines an amount of displacement of the rotor R per pulse of the pulse signal. The estimated position signal is an analog or digital signal. Upon receiving a pulse signal, the motor control circuit 20 determines the command voltage value based on an estimated position value of the rotor R acquired from the position estimation device 30 and the variable step-size information read from the variable step-size memory 40. The motor driving circuit 10 changes the position of the rotor R based on the command voltage value.

A method and system for automatically adjusting an iris opening in an imaging system. The method includes an iterative process that continues to adjust the camera's iris opening until an algorithm stopping condition is met. More particularly, a processor determines a brightness for the image at the current aperture setting. The processor classifies the image according to one of at least two brightness regime classifications. Based on the classifying step, the processor selects a pre-set optimal brightness parameter. The processor compares the brightness value of the image to the pre-set optimal value. The camera's iris opening is automatically adjusted based on a formula that takes into account, the current f-stop setting, the current brightness value, and the optimal brightness value. The iterative process continues until an algorithm stopping condition is met.