Patent ID: 8963458
Filing Date: 2015-02-24
Classification: B25B,B25F,H02J,H02P

Abstract:
1. An electric tool powered by a secondary battery as a power source, comprising: an output section configured to be transmitted thereto a rotation of a motor directly or through a decelerator; a voltage measurement section configured to measure a battery voltage; a storage means configured to store, as a reference voltage, a voltage value of the battery voltage that has been measured preliminarily when a motor-lock is occurring; a control means configured to control a driving of said motor; and a temperature sensor for measuring a temperature, wherein said control means is configured to decide that said motor is in a locked state and then stop or decelerate said motor upon detecting that the battery voltage measured through said voltage measurement section is maintained lower than or equal to the reference voltage stored in said storage means for a predetermined period of time during the driving of said motor, and wherein said control means is configured to change the reference voltage that is compared with the battery voltage during the driving of said motor, on the basis of the temperature measured through said temperature sensor.