Patent ID: 7737834

Claim:
A data communication system installed in an electric machine including an electrically conductive body insulated from a ground and having a surface, the system transmitting and receiving information between two different locations in the electric machine, the system comprising: a transmission terminal and a reception terminal both mounted on the electric machine; a transmission-side opposed conductive member provided on the transmission terminal so as to be opposed to the conductive body; a transmission circuit provided on the transmission terminal for applying voltage between the transmission-side opposed conductive member and the conductive body, thereby changing electric field generated on the entire surface of the conductive body, said voltage being changed according to information to be transmitted; a reception-side opposed conductive member provided on the reception terminal so as to be opposed to the conductive body, thereby generating potential difference according to the electric field between the conductive body and the reception-side opposed conductive member; a reception circuit provided on the reception terminal for receiving the information based on a change in the potential difference between the conductive body and the reception-side opposed conductive member; and a voltage follower circuit, provided on the reception circuit, constructed and arranged to receive as an input the potential difference between the conductive body and the reception-side opposed conductive member.