| 摘要 |
PURPOSE: An external control unit for hand-held electric screwdriver is provided to reduce a material cost and a manufacturing cost by using only two electric wires to connect a controller to the hand-held electric screwdriver. CONSTITUTION: An external control unit for hand-held electric screwdriver includes an operating portion(20), a braking portion(30), a control portion(40), an LED display portion(50), and a rotation number calculation portion(60). The operating portion(20) is formed with a plurality of resistors, a photo sensor, a switch, a field effect transistor, and a capacitor. The braking portion(30) is formed with a plurality of transistors, a field effect transistor, a plurality of resistors, a plurality of capacitors, a plurality of diodes, a NOT gate, and a constant voltage IC to stop a motor of the hand-held electric screwdriver. The control portion(40) is formed with a plurality of RS flipflop ICs, a plurality of NOT gates, a plurality of diodes, a plurality of capacitors, a field effect transistor, a plurality of comparator ICs, and a plurality of resistors to sense and control an operating state of the hand-held electric screwdriver. The LED display portion(50) is formed with a plurality of LEDs, a plurality of resistors, and a NOT gate to display the operating state of the hand-held electric screwdriver and a lifetime of a brush. The rotation number calculation portion(60) is formed with an IC, a plurality of resistors, a plurality of capacitors, and a switch to select the rotation number of the hand-held electric screwdriver.
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