Abstract: An optical transmitter according to one embodiment includes: a plurality of light emitting elements; a plurality of light receiving elements that monitor output lights from the respective plurality of light emitting elements; a housing that mounts the plurality of light emitting elements and the plurality of light receiving elements; and a wiring board which is mounted on the housing and which is provided with a first region having a pad electrically connected to the light emitting element and a second region disposed at a position lower than the first region and having a pad electrically connected to the light receiving element.

Abstract: One object is to reduce a volume occupied by a device disposed in a first space spatially limited to a large degree. An electric actuator diving and controlling device is provided with a drive unit positioned in a first space in a piece of equipment and configured to apply power to an electric actuator and a control unit positioned in a second space in the piece of equipment and configured to transmit, to the drive unit, a power command signal including information related to power to be applied to the electric actuator. The first space having the drive unit positioned therein is limited compared with the second space having the control unit positioned therein.

Abstract: One object is to prevent a component having low environmental resistance from being disposed in an environmentally harsh space. An electric actuator driving and controlling device is provided with a drive unit positioned in a first environment in a piece of equipment and configured to apply power to an electric actuator and a control unit positioned in a second environment in the piece of equipment and configured to transmit, to the drive unit, a power command signal including information related to power to be applied to the electric actuator. The first environment having the drive unit positioned therein is harsh compared with the second environment having the control unit positioned therein.

Abstract: One object is to reduce a volume occupied by a device disposed in a first space spatially limited to a large degree. An electric actuator diving and controlling device is provided with a drive unit positioned in a first space in a piece of equipment and configured to apply power to an electric actuator and a control unit positioned in a second space in the piece of equipment and configured to transmit, to the drive unit, a power command signal including information related to power to be applied to the electric actuator. The first space having the drive unit positioned therein is limited compared with the second space having the control unit positioned therein.

Abstract: A controller that performs pulse width modulation control of a three-phase inverter circuit includes a three-phase modulation voltage command value generation unit, a two-phase modulation voltage command value generation unit, a voltage command switching unit, and a PWM signal output unit. The voltage command switching unit switches a voltage command value to a two-phase modulation voltage command value when a determination value becomes larger than or equal to a first threshold value, and switches the voltage command value to a three-phase modulation voltage command value when the determination value becomes smaller than a second threshold value, which is smaller than the first threshold value.

Abstract: A controller that performs pulse width modulation control of a three-phase inverter circuit includes a three-phase modulation voltage command value generation unit, a two-phase modulation voltage command value generation unit, a voltage command switching unit, and a PWM signal output unit. The voltage command switching unit switches a voltage command value to a two-phase modulation voltage command value when a determination value becomes larger than or equal to a first threshold value, and switches the voltage command value to a three-phase modulation voltage command value when the determination value becomes smaller than a second threshold value, which is smaller than the first threshold value.

Abstract: The command signal processing unit outputs, when a first PWM frequency command signal is received, a high-PWM frequency command signal such that an asynchronous PWM control is performed at a PWM frequency of a predetermined constant frequency. The command signal processing unit outputs, when a second PWM frequency command signal is received, a low-PWM frequency command signal such that an asynchronous or synchronous PWM control is performed at a frequency lower than the above-described frequency. The PWM frequency control unit controls the PWM frequency such that an asynchronous PWM control is performed if a motor has a rotational speed less than a predetermined rotational speed and that a synchronous PWM control is performed if the motor has a rotational speed greater than or equal to the predetermined rotational speed, when a low-PWM frequency command signal is input.

Abstract: The command signal processing unit outputs, when a first PWM frequency command signal is received, a high-PWM frequency command signal such that an asynchronous PWM control is performed at a PWM frequency of a predetermined constant frequency. The command signal processing unit outputs, when a second PWM frequency command signal is received, a low-PWM frequency command signal such that an asynchronous or synchronous PWM control is performed at a frequency lower than the above-described frequency. The PWM frequency control unit controls the PWM frequency such that an asynchronous PWM control is performed if a motor has a rotational speed less than a predetermined rotational speed and that a synchronous PWM control is performed if the motor has a rotational speed greater than or equal to the predetermined rotational speed, when a low-PWM frequency command signal is input.