Abstract: A lock state occurrence determination apparatus includes a counter, a reset device, a reference time changing device, a lock state determination device, and an invalidation device. The invalidation device performs, in a case where a false determination of occurrence of a lock state of a motor is caused by the lock state determination device due to an operation input to operate a rotation speed of the motor, at least one of a first invalidation operation to invalidate the lock state determination device and a second invalidation operation to invalidate continuation of a counting operation by the counter.

Abstract: A rechargeable power tool includes a direct current motor, a switching circuit, at least one speed setting unit, a duty ratio setting unit, a drive unit, an operation amount detecting unit, an abnormality determining unit, and a determination threshold setting unit. The abnormality determining unit compares an operation amount detected by the operation amount detecting unit and a determination threshold set based on the operation amount to thereby determine whether or not an operation state of the rechargeable power tool is abnormal. The determination threshold setting unit sets the determination threshold in a continuous or stepwise manner in accordance with a rotation speed set by the speed setting unit.

Abstract: A motor controller comprises a processor selectively outputting an on-signal to either one of an upper arm switching element and a lower arm switching element based upon a detected position by the position sensor, gate drivers inputting a driving voltage to the gates of the switching elements by shifting a level of the on-signal from the processor to the upper arm switching element and a bootstrap capacitor configured to be charged while the upper arm switching element is turned off and to behave as a voltage supply for the gate driver while the upper arm switching element is turned on. The processor is configured to reduce a set duty ratio when the set duty ratio is equal to or larger than a predetermined value (e.g. 80 percents) and a rotational position of the motor does not change for a first predetermined time. This motor controller can prevent the switching element from a burnout even if the motor is locked.

Abstract: A pressure regulating valve unit 7 is configured to be electrically driven according to a detection value of a detection unit 74 adapted to detect an amount of brake application effort made by a brake operation member 5 so as to switch states of the vehicle brake apparatus between a state where a boosted hydraulic pressure chamber 9 is made to communicate with a hydraulic pressure generating source 6 while a communication between the boosted hydraulic pressure chamber 9 and a reservoir R is interrupted, a state where the communication between the boosted pressure chamber 9 and the hydraulic pressure generating source 6 is interrupted while the boosted pressure chamber 9 is made to communicate with the reservoir R, and a state where the boosted hydraulic pressure chamber 9 is disconnected from both the hydraulic pressure generating source 6 and the reservoir R.

Abstract: A pressure regulating valve unit is configured to regulate the output hydraulic pressure of a hydraulic pressure generating source through electrical control for application to a boosted hydraulic pressure chamber, and a release valve is interposed between the boosted hydraulic pressure chamber and a reservoir which is adapted to the hydraulic pressure in the boosted hydraulic pressure chamber to the reservoir side when the pressure regulating valve unit fails.

Abstract: An electric power tool, which comprises a motor that drives a tool, a power source unit that applies voltage to the motor, a main switching circuit that makes/breaks an electrical connection between the power source unit and the motor, an illuminator that illuminates a work spot, a switching device that electrically connects the illuminator to the power source unit, and an OR circuit that is electrically connected to terminals of the motor to the base terminal is provided. The OR circuit electrically connects one of the motor terminals at which a voltage is higher to the base terminal.

Abstract: A motor controller comprises a processor selectively outputting an on-signal to either one of an upper arm switching element and a lower arm switching element based upon a detected position by the position sensor, gate drivers inputting a driving voltage to the gates of the switching elements by shifting a level of the on-signal from the processor to the upper arm switching element and a bootstrap capacitor configured to be charged while the upper arm switching element is turned off and to behave as a voltage supply for the gate driver while the upper arm switching element is turned on. The processor is configured to reduce a set duty ratio when the set duty ratio is equal to or larger than a predetermined value (e.g. 80 percents) and a rotational position of the motor does not change for a first predetermined time. This motor controller can prevent the switching element from a burnout even if the motor is locked.

Abstract: A phase difference detecting device includes a splitter for splitting laser beams into a first group which will travel along a first path and a second group which will travel along a second path, a beam selection/extraction unit for selecting, as reference light, one beam from the first group to allow it to pass therethrough, a path length changing unit for changing the length of the first path, a combining unit for combining the reference light and beams which construct the second group to produce interference light, and a detector for detecting the intensity of the interference light. The device changes the length of the first path using the path length changing unit to detect a path length which maximizes the intensity of the interference light for each of the beams which construct the second group, and determines a phase difference among the beams from the detected path length.