An air manifold system for supplying an agricultural product to a plurality of metering devices comprises a product hopper having a product flow cavity, the product cavity separated from a first plenum by an air agitator sandwiched between the first plenum and the product flow cavity. The hopper comprises a plurality of nozzles extending through a wall of the hopper. A venturi assembly is in fluid communication with at least one nozzle. A first forced air stream flows through the first plenum and the air agitator into the product flow cavity to agitate and entrain agricultural product in the first air stream, and the first air stream carries the entrained agricultural product into the nozzles. A second forced air stream flows through the venturi assembly to accelerate the first air stream and the entrained product towards and through the supply hoses connected to the nozzles.

In a described example an apparatus includes: an FET driver circuit configured to supply current to a coil in a stepper motor, the FET driver circuit configured to regulate the current to the coil using a fixed delta current; a current chopper pulse width modulated circuit coupled to the FET driver circuit configured to supply pulses corresponding to a step control signal and a direction control signal; a back electromotive force (BEMF) monitor coupled to the current chopper circuit configured to measure an off time pulse and to output a BEMF monitor signal; and a controller coupled to the current chopper pulse width modulated circuit to supply the step and direction control signals and coupled to receive the BEMF monitor signal.

In a described example an apparatus includes: an FET driver circuit configured to supply current to a coil in a stepper motor, the FET driver circuit configured to regulate the current to the coil using a fixed delta current; a current chopper pulse width modulated circuit coupled to the FET driver circuit configured to supply pulses corresponding to a step control signal and a direction control signal; a back electromotive force (BEMF) monitor coupled to the current chopper circuit configured to measure an off time pulse and to output a BEMF monitor signal; and a controller coupled to the current chopper pulse width modulated circuit to supply the step and direction control signals and coupled to receive the BEMF monitor signal.

A controller is provided for driving a stepper motor with a magnetic rotor and at least one coil. The controller has a power stage for supplying the at least one coil with current, at least one analog Hall sensor for providing a signal as a function of the position of the magnetic rotor with respect to the Hall sensor, and a feedback line connecting the Hall sensor with the power stage to feed the signal of the Hall sensor back to the power stage.

A controller is provided for driving a stepper motor with a magnetic rotor and at least one coil. The controller has a power stage for supplying the at least one coil with current, at least one analog Hall sensor for providing a signal as a function of the position of the magnetic rotor with respect to the Hall sensor, and a feedback line connecting the Hall sensor with the power stage to feed the signal of the Hall sensor back to the power stage.

A movable body drive device that controls a drive unit configured to drive a movable body arranged on a game machine has a communication unit that receives a control command for regulating a destination position of the movable body, a storage unit that stores a current position of the movable body, and a control unit that determines, based on a difference between the destination position and the current position or a moving direction in an immediately previous action of the movable body, a moving direction in the next action of the movable body and to control the drive unit such that the movable body is moved along the moving direction in the next action until the movable body reaches the destination position.

A movable body drive device that controls a drive unit configured to drive a movable body arranged on a game machine has a communication unit that receives a control command for regulating a destination position of the movable body, a storage unit that stores a current position of the movable body, and a control unit that determines, based on a difference between the destination position and the current position or a moving direction in an immediately previous action of the movable body, a moving direction in the next action of the movable body and to control the drive unit such that the movable body is moved along the moving direction in the next action until the movable body reaches the destination position.

A motor control apparatus operates in a first control mode in which the values of a torque current component and an excitation current component are controlled so that the difference between an instruction phase and a rotation phase is decreased and a second control mode in which constant current is supplied to a winding of a motor. The second control mode is switched to the first control mode if the rotation speed is varied from a value lower than a first threshold value to a value not lower than the first threshold value in the second control mode and the first control mode is kept even if the rotation speed is varied from a value not lower than the first threshold value to a value that is not lower than a second threshold value and that is lower than the first threshold value in the first control mode.

A motor control apparatus operates in a first control mode in which the values of a torque current component and an excitation current component are controlled so that the difference between an instruction phase and a rotation phase is decreased and a second control mode in which constant current is supplied to a winding of a motor. The second control mode is switched to the first control mode if the rotation speed is varied from a value lower than a first threshold value to a value not lower than the first threshold value in the second control mode and the first control mode is kept even if the rotation speed is varied from a value not lower than the first threshold value to a value that is not lower than a second threshold value and that is lower than the first threshold value in the first control mode.

Systems and methods for operating a stepper motor of a pump at a desired low velocity include memory for storing information corresponding to an intake velocity profile. The intake velocity profile represents an optimized acceleration curve for operating the stepper motor over a range of motor velocities during an intake cycle. A processor of a system controller dynamically accesses the memory during the intake cycle to acquire the information representing the intake velocity profile and issues a series of pulses to the stepper motor based on this information. In response to the pulses, the stepper motor accelerates in accordance with the optimized acceleration curve represented by the intake velocity profile. The optimized acceleration curve is based on the available torque of the stepper motor across a range of motor velocities and enables the motor to operate with greater torque utilization and less margin than traditional linear acceleration profiles.