A control apparatus includes a processor and a memory storing a program that, when executed by the processor, causes the processor to acquire at least one of movement information related to a movement status of a device having a step motor or environment information related to an environment where the device is located, and select one of a plurality of control modes to control the step motor according to the at least one of the movement information or the environment information. The plurality of control modes includes a first control mode and a second control mode. In the second control mode, a number of steps is less than that in the first control mode, and a force to keep a rotor of the step motor at a position is smaller than that in the first control mode or a power consumption is less than that in the first control mode.

A control apparatus includes a processor and a memory storing a program that, when executed by the processor, causes the processor to acquire at least one of movement information related to a movement status of a device having a step motor or environment information related to an environment where the device is located, and select one of a plurality of control modes to control the step motor according to the at least one of the movement information or the environment information. The plurality of control modes includes a first control mode and a second control mode. In the second control mode, a number of steps is less than that in the first control mode, and a force to keep a rotor of the step motor at a position is smaller than that in the first control mode or a power consumption is less than that in the first control mode.

A motor control apparatus that controls a stepping motor includes a calculation unit configured to determine a time with respect to a distance based on a theoretical formula expressing a parameter in an acceleration period or deceleration period of the stepping motor. The calculation unit includes a first calculation unit and a second calculation unit. The first calculation unit is configured to apply an iterative root-finding procedure to a distance which is a function of a time included in the theoretical formula to determine the time with respect to the distance of the n-th step expressed using a reciprocal of a derivative of the function. The second calculation unit is configured to apply the iterative root-finding procedure to the reciprocal of the derivative to determine the reciprocal of the derivative at a time when the first calculation unit determines the time with respect to the distance of the n-th step.

A motor control apparatus that controls a stepping motor includes a calculation unit configured to determine a time with respect to a distance based on a theoretical formula expressing a parameter in an acceleration period or deceleration period of the stepping motor. The calculation unit includes a first calculation unit and a second calculation unit. The first calculation unit is configured to apply an iterative root-finding procedure to a distance which is a function of a time included in the theoretical formula to determine the time with respect to the distance of the n-th step expressed using a reciprocal of a derivative of the function. The second calculation unit is configured to apply the iterative root-finding procedure to the reciprocal of the derivative to determine the reciprocal of the derivative at a time when the first calculation unit determines the time with respect to the distance of the n-th step.

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.

In order to suppress high-frequency noise in micro-step driving of a stepping motor, a motor control device (100) includes an H bridge circuit (20) and control means for driving a switching element of the H bridge circuit (20) with a PWM signal and for setting a charge mode, a fast attenuation mode, or a slow attenuation mode for a motor coil. In a range from an electrical angle where the reference current value starts descending to an electrical angle of +52, the control means switches the H bridge circuit (20) every PWM cycle to the charge mode and then to the slow attenuation mode. In a range exceeding +52 and to +90 degrees where the reference current value starts ascending, the control means switches the H bridge circuit (20) every PWM cycle to the charge mode and, if the motor current exceeds the reference current value, then the control means switches it to the fast attenuation mode and further to the slow attenuation mode.

In order to suppress high-frequency noise in micro-step driving of a stepping motor, a motor control device (100) includes an H bridge circuit (20) and control means for driving a switching element of the H bridge circuit (20) with a PWM signal and for setting a charge mode, a fast attenuation mode, or a slow attenuation mode for a motor coil. In a range from an electrical angle where the reference current value starts descending to an electrical angle of +52, the control means switches the H bridge circuit (20) every PWM cycle to the charge mode and then to the slow attenuation mode. In a range exceeding +52 and to +90 degrees where the reference current value starts ascending, the control means switches the H bridge circuit (20) every PWM cycle to the charge mode and, if the motor current exceeds the reference current value, then the control means switches it to the fast attenuation mode and further to the slow attenuation mode.

A soundstage device to generate a random noise signal may include a container to include a virtual assistant. The container may include a base to mount the virtual assistant and a lid to connect to the base; the lid may be movable between a first position and a second position, and the lid may include a random noise generator to generate the random noise signal.

A soundstage device to generate a random noise signal may include a container to include a virtual assistant. The container may include a base to mount the virtual assistant and a lid to connect to the base; the lid may be movable between a first position and a second position, and the lid may include a random noise generator to generate the random noise signal.

This motor control device has an inexpensive configuration and enhances motor current target value tracking. This motor control device has an H bridge circuit that has a switching element and is connected to a motor coil provided in a motor, and a control means that drives the switching element at each prescribed PWM period and specifies an operation mode for the H bridge circuit from among a charge mode for increasing the motor current (Icoil) flowing through the motor coil, a fast decay mode for decreasing the motor current, and a slow decay mode. In each PWM period, the control means selects one of the operation modes on the basis of the result of comparing the motor current and a current reference value (Iref) before the time that has passed from the start of the PWM period reaches a prescribed current control re-execution time (Tr) and selects one of the operation modes on the basis of the result of comparing the motor current and the current reference value after the time that has passed reaches the current control re-execution time.