| 摘要 |
PURPOSE:To eliminate the over-fastening of a screw with the stoppage of a tool in a desired rotation number and to prevent the screw from its breakdown, by providing an automatic stoppage control circuit which makes an automatic stoppage with the control of a control circuit at the time when reaching the total rotation number set by a setting switch from after the actuation. CONSTITUTION:On actuation of a tool, one of the gate signals of a MOSFET is input to a divider 22 as a positional signal. Now, the output of the divider 22 becomes the shaft tip output of the tool and is input to a counter 23. The rotation number counted by this counter 23 is then compared by a comparator 25 with the data of a setting switch 24 for setting the total rotation number. This comparator 25 reverses the output in the case of a rotation number set value and the detected rotation number being coincident or the number of rotation number detecting signals becoming more and inputs it to the brake terminal of the signal distribution circuit of a control circuit, and a brushless motor is stopped. |
