| 摘要 |
<p>To an electrical tool for machining surfaces is associated a control and diagnostic unit comprising an electrical current sensor (6) adapted to measure the flow of electrical current fed to the tool motor, an electronic circuit (9) for counting and storing the flow time and/or the quantity of electrical current fed to the tool motor, and at least one indicating device (8) adapted to indicate the instant at which said flow time and/or said quantity of current exceeds a predetermined value indicating the need for maintenance of the tool. There may be provided an interface device (14) for communicating information to an external central unit.</p> |
