| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent harmful influences of surge voltage or the like in an electric tool enabling a computer program and a control parameter for driving a motor to be changed from an external device. <P>SOLUTION: The electric tool includes a motor for driving a tip tool, a control circuit board 9 for mounting a control circuit which controls rotation of the motor, and a communication connector 47b for removing/attaching a communication line that connects the control circuit and the external connection device. In the electric tool, the communication connector 47b is placed on a connector substrate 47a provided independently of the control circuit board 9, and electrostatic protection means 211 to 214 are provided on the connector board 47a. The electrostatic protection means 211 to 214 comprise varistors for connecting communication lines and ground lines. The varistors are formed into chip shapes and placed in such a way that a plurality of connection terminals 201 to 204 comprising the communication lines and a connection terminal 205 for ground are each connected. <P>COPYRIGHT: (C)2013,JPO&INPIT |
