Abstract: A battery voltage detection device includes a battery; a voltage detection circuit; and a low-pass filter provided between the battery and the voltage detection circuit. The low-pass filter includes a capacitor of which one end is connected to a terminal of the battery and the other end is connected to a voltage source outputting a voltage higher than a terminal voltage of the battery.

Abstract: A battery voltage detector includes, but is not limited to: a voltage detection circuit; and a voltage processor. The voltage detection circuit includes, but is not limited to: a capacitor configured to be charged by a battery cell; a pair of output terminals; an output switch; and a voltage processor. While the capacitor is charged, the output switch is configured to be off-state and insulate the capacitor from the pair of the output terminals. After the capacitor is charged, the output switch is configured to be on-state and connect the capacitor to the pair of the output terminals. The voltage processor is configured to obtain, as a cell voltage, a voltage between the output terminals of the voltage detection circuit while the output switch is on-state. A high-potential output terminal of the pair of the output terminals is connected to a power line via a pull-up resistor.

Abstract: A battery voltage detector includes a voltage detection circuit and a voltage processor. The voltage detection circuit includes a capacitor, a pair of output terminals and an output switch. A power source voltage is supplied from a power source to a higher voltage output terminal of the pair of output terminals in the voltage detection circuit. While the output switch is turned off, the voltage processor takes in a voltage between the output terminals as a voltage for determining a defect and determines whether or not a false detection of the cell voltage has occurred based on the voltage for determining the defect.

Abstract: A battery voltage detector includes, but is not limited to: a voltage detection circuit; and a voltage processor. The voltage detection circuit includes, but is not limited to: a capacitor configured to be charged by a battery cell; a pair of output terminals; an output switch; and a voltage processor. While the capacitor is charged, the output switch is configured to be off-state and insulate the capacitor from the pair of the output terminals. After the capacitor is charged, the output switch is configured to be on-state and connect the capacitor to the pair of the output terminals. The voltage processor is configured to obtain, as a cell voltage, a voltage between the output terminals of the voltage detection circuit while the output switch is on-state. A high-potential output terminal of the pair of the output terminals is connected to a power line via a pull-up resistor.

Abstract: A circular saw (1) includes a base plate (2) and a saw blade assembly (3) including a lower blade guard (9) for covering a saw blade (6). The blade guard includes a sleeve portion (10) rotatably fitted on a bearing box (8) coupled to the saw blade assembly and a sectoral portion (11) extending radially from the sleeve portion in the rear of the blade. A connecting bar (13) projects radially rearward from the sectoral portion. A spring (14) is stretched between the top of the connecting bar (13) and a lower rear portion of an upper blade guard (4) close to the base plate. When not in use, torque, generated as the product of the spring's tensile force and the perpendicular distance (S) from the line of action or the force to the axis of rotation (O), rotates the blade guard to a closed position.

Abstract: A circular saw (1) includes a base plate (2) and a saw blade assembly (3) which in turn includes a lower blade guard (9) for covering a saw blade (6). The blade guard includes a sleeve portion (10) rotatably fitted on a bearing box (8) coupled to the saw blade assembly and a sectoral portion (11) which extends radially from the sleeve portion in the rear of the blade. A connecting bar (13) projects radially rearward from the sectoral portion at a 40-degree angle to the base plate. A spring (14) is stretched between the top of the connecting bar (13) and a lower rear portion of an upper blade guard (4) close to the base plate. When not in use, the blade guard is rotated to the closed position by the torque generated as the product of the spring's tensile force and the perpendicular distance (S) from the line of action or the force to the axis of rotation (O).