An apparatus for estimating a motor RPM in an electronic brake system may include: a current signal amplifier configured to amplify a voltage applied across a motor driver by a current which flows while the motor driver is turned on, the motor driver being included in a motor driving circuit configured to apply motor driving power to a motor or remove the motor driving power according to a switch-on/off of the motor driver; and a controller configured to detect a waveform with a one-period time from periodically repeated waveforms by processing the signal waveform amplified by the current signal amplifier, calculate a one-rotation time based on the one-period time and the number of commutators of the motor, and calculate a motor RPM using the one-rotation time.

A drive control system for a linear driver may include a power module, a controller, a motor drive module, a motor, and a position control module. The power module may be connected to the controller, the controller may be connected to the motor drive module, and the position control module may be connected in series between the controller and the motor drive module to form a control loop. The power module may be connected to the motor drive module to input power to the motor drive module, and the motor drive module may be connected to the motor to form a drive loop. The control loop may control the work of the drive loop, and the drive loop may directly form a loop in series connection with the motor and the power module through the motor drive module.

A system and a method for automatically correcting a rotational speed of a motor of a fan are provided. After the fan is moved from an open space to a closed space, a sample and hold circuit samples and holds working periods of a driving signal by which the motor is driven to rotate at a first rotational speed as a first sampled working period, and a working period of a driving signal by which the motor is driven to rotate at a second rotational speed. An arithmetic circuit calculates a difference between the first sampled working period and a first reference working period, and a difference between the second sampled working period and a second reference working period. The arithmetic circuit calculates other working periods of driving signals by which the motor is driven to rotate at other rotational speeds based on the differences.

A system and a method for automatically correcting a rotational speed of a motor of a fan are provided. After the fan is moved from an open space to a closed space, a sample and hold circuit samples and holds working periods of a driving signal by which the motor is driven to rotate at a first rotational speed as a first sampled working period, and a working period of a driving signal by which the motor is driven to rotate at a second rotational speed. An arithmetic circuit calculates a difference between the first sampled working period and a first reference working period, and a difference between the second sampled working period and a second reference working period. The arithmetic circuit calculates other working periods of driving signals by which the motor is driven to rotate at other rotational speeds based on the differences.

A motor control device is a device for controlling a drive of a DC motor which is interlocked with an output shaft portion of an actuator. The motor control device includes: a relative position obtainer detecting current fluctuations when switching a connection between a commutator and a brush in the DC motor or when rotating the DC motor and obtaining relative position information of the output shaft portion; and an absolute position obtainer obtaining absolute position information of the output shaft portion using a potentiometer. The motor control device further includes: an actual position setter setting actual position information of the output shaft portion based on at least one of the absolute position information and the relative position information.

An apparatus can comprise a circuit and an electrical element coupled to the circuit. The circuit can include a pulse generator to generate an electrical pulse having a first power and a load. The electrical element can be configured to receive heat that is converted into electrical energy by the circuit to apply a second power, greater than the first power, to the load.

An apparatus can comprise a circuit and an electrical element coupled to the circuit. The circuit can include a pulse generator to generate an electrical pulse having a first power and a load. The electrical element can be configured to receive heat that is converted into electrical energy by the circuit to apply a second power, greater than the first power, to the load.

A motor control system includes a DC motor and a ripple count circuit. The DC motor includes a rotor that rotates in response to a drive current. The rotation of the rotor generates a mechanical force that drives a component. The ripple count circuit includes an active filter circuit and a parasitic pulse cancellation circuit. The active filter circuit is configured to filter the drive current and to generate a pulsed signal. The parasitic pulse cancelation circuit is in signal communication with the ripple count circuit to receive the pulsed signal and generates a ripple count signal that excludes parasitic pulses included in the pulsed signal having a parasitic voltage level that exceeds a voltage level of a voltage threshold. The parasitic pulse cancelation circuit actively adjusts the voltage level of the voltage threshold based at least in part on a rotational direction of the rotor.

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.

The invention relates to a continuous cable winch comprising a drive unit (20) and an output unit (60) for applying a drive force to a cable, which output unit is coupled to the drive unit (20). According to the invention, it is proposed that the drive unit (20) has a frequency converter (30) with a primary side (32) for drawing current from a power supply system (33) and a secondary side (36) for outputting an AC voltage (U.sub.U, U.sub.V, U.sub.W), an AC motor (40) for driving the continuous cable winch (10) at a variable rotation speed (ω.sub.1), which AC motor is supplied with the AC voltage (U.sub.U, U.sub.V, U.sub.W) by the frequency converter (30), a control unit (50) which is interconnected with the frequency converter (30) and the AC motor (40) for the purpose of controlling the drive unit (20), wherein the control unit (50) is designed to change the rotation speed (ω.sub.1) of the AC motor (40) by means of the frequency converter (30).