A windshield wiper system includes a three-phase motor, the three-phase inverter, a brake circuit, and a controller. The controller transmits commutation signals to the three-phase inverter to drive the motor according to an inboard-to-outboard speed profile and to drive the motor according to an outboard-to-inboard speed profile. The controller activates the brake circuit based on the inboard-to outboard speed profile, or the outboard-to-inboard speed profile, and a direct current bus voltage.

A method for driving an actuator of an HVAC system having a region of mechanical play is provided, and which comprises the steps of: a] monitoring a position of a movable member of the HVAC system or at least one rotatable element of the actuator to determine when the region of mechanical play has been entered or exited; and b] ramping a drive power to the actuator between a zero-velocity drive power and a steady-state-velocity drive power during the region of mechanical play. The HVAC system implementing the above method is not only capable of reducing the noise produced by an HVAC system, but is also capable of reducing an over-powering of the actuator when there is a low load on the system.

A method for driving an actuator of an HVAC system having a region of mechanical play is provided, and which comprises the steps of: a] monitoring a position of a movable member of the HVAC system or at least one rotatable element of the actuator to determine when the region of mechanical play has been entered or exited; and b] ramping a drive power to the actuator between a zero-velocity drive power and a steady-state-velocity drive power during the region of mechanical play. The HVAC system implementing the above method is not only capable of reducing the noise produced by an HVAC system, but is also capable of reducing an over-powering of the actuator when there is a low load on the system.

An inverter includes: a converter circuitry to convert an alternating-current voltage to a direct-current voltage; an inverter circuitry to convert a direct-current voltage obtained by conversion by the converter circuitry to an alternating-current voltage and to supply the alternating-current voltage obtained by conversion to a load; a current detector to detect an output current of the inverter circuitry; a calculator to calculate an output frequency based on the output current detected by the current detector, and a pulse-signal outputter to output a pulse signal based on the output frequency calculated by the calculator. The inverter circuitry converts the direct-current voltage obtained by conversion by the converter circuitry to the alternating-current voltage based on the pulse signal output from the pulse-signal outputter, so as to obtain a frequency corresponding to the magnitude of the load.

An elevator control device includes a filter to remove a direct current component and a torque component derived from rope imbalance from a torque command value applied to a drive motor, and an inertia identifying mechanism to identify an inertia value of an elevator based on an output obtained when a speed detection signal is input into the filter, and an acceleration converting mechanism, which are connected in series, and an output obtained when the torque command value is input into the filter. As a result, the inertia value of a high-lift elevator can be calculated accurately.

An elevator control device includes a filter to remove a direct current component and a torque component derived from rope imbalance from a torque command value applied to a drive motor, and an inertia identifying mechanism to identify an inertia value of an elevator based on an output obtained when a speed detection signal is input into the filter, and an acceleration converting mechanism, which are connected in series, and an output obtained when the torque command value is input into the filter. As a result, the inertia value of a high-lift elevator can be calculated accurately.

The present application provides a servo motor drive circuit and a 3D printing apparatus, a motion controller is configured to send a drive enable signal to the timer; a pulse period providing unit is configured to send a pulse period value to the timer and the first comparing unit at beginning of each pulse period; the timer is configured to perform initialization in response to the received pulse period value during enabling of the drive enable signal, perform cyclic timing by taking the pulse period value as a timing period, and send a timing duration to the first comparing unit; and the first comparing unit is configured to acquire current level information that satisfies a preset duty ratio according to the preset duty ratio, the pulse period value, and the timing duration, and send a drive signal to a servo motor according to the current level information.

A maximum acceleration identification system determines a suitable maximum acceleration for transitioning a given motion/motor system to a target position or velocity, taking the friction of the motion system into consideration. The maximum acceleration determined by the maximum acceleration identification system can then be used by the motion control system as the acceleration limit for generating motion profiles. Thus, motion profiles can be generated that are closer to the true maximum acceleration supported by the motion system without violating the mechanical and electrical constraints of the system as characterized in part by the viscous friction, resulting in a more time-optimal move. In some embodiments, the maximum acceleration identification system can automatically set the maximum acceleration of the control system's profile generator to be equal to the derived value, thereby eliminating the need for the maximum acceleration to be selected and set by the system designer.

A method for driving an actuator of an HVAC system is provided, and which comprises the steps of: a] determining an actuation command to the actuator; and b] ramping a drive power to the actuator between a steady-state-velocity drive power and a zero-velocity drive power to effect a required acceleration or deceleration to a movable member of the HAVC system without or substantially without over-powering of the actuator. An HVAC system is also provided. The HVAC system implementing the above method is not only capable of reducing the noise produced by an HVAC system, but is also capable of reducing an over-powering of the actuator when there is a low load on the system.

A method for driving an actuator of an HVAC system is provided, and which comprises the steps of: a] determining an actuation command to the actuator; and b] ramping a drive power to the actuator between a steady-state-velocity drive power and a zero-velocity drive power to effect a required acceleration or deceleration to a movable member of the HAVC system without or substantially without over-powering of the actuator. An HVAC system is also provided. The HVAC system implementing the above method is not only capable of reducing the noise produced by an HVAC system, but is also capable of reducing an over-powering of the actuator when there is a low load on the system.