Measuring current from an electrode using a non-linear element

An arrangement for generating a resistivity image, comprising:

• a drill bit with cutters configured to be placed within a wellbore, the cutters configured to create further sections of the wellbore upon rotation, the drill bit having an end with threads for engagement;
• at least one section of drill string connected to the drill bit through a matching set of threads for engagement;
• a receiver toroid connected to the at least one section of drill string along at least a portion of the drill string;
• a transmitter toroid connected to the at least one section of drill string and located at least a portion of the drill string away from the receiver toroid;
• at least one stabilizer connected to the at least one section of drill string, the stabilizer configured to stabilize the at least one section of drill string and the drill bit upon rotation of the connected drill string and the drill bit by contacting an exterior portion of the wellbore;
• a power source connected to the transmitter toroid and the receiver toroid;
• an electrode arrangement placed at the drill bit, wherein the electrode arrangement is electrically connected to the drill bit through a non-linear circuit element;
• and
• a computer arrangement connected to the receiver toroid, the computer arrangement configured to receive data from the receiver toroid and generate a resistivity image.