Electric Power Tool with Communication Line to Battery Pack

摘要

An electric power tool has a drive motor and an electronic control unit. Power is supplied by a battery pack with several individual cells and a monitoring circuit for the operating parameters of the cells. A communication line connects electronic control unit and monitoring circuit. Digital data are exchanged through the communication line between electronic control unit and monitoring circuit. A controller controls data traffic through sending and receiving units. The communication voltage is higher than a permissible input voltage level of the controller and lower than a maximum battery pack voltage. The receiving unit, as a filter, converts a received first signal level that is lower than a first voltage to a LOW signal and lowers a received second signal level that is higher than a second voltage to the input voltage level of the controller and relays the second signal level as a HIGH signal.