Abstract: A novel cathodic protection system is provided that automatically controls and adjusts the voltage potential between an anode and a structure to protect the structure from corrosion. The cathodic protection system is self-powered, requiring no external power source or batteries. A cathodic protection circuit is configured to provide a cathodic protection current from the anode to the structure through an electrolyte. A power generation circuit is configured to generate power from a galvanic cell formed from the anode and an isolated electrode when cathodic protection is interrupted. A voltage potential control circuit is powered by the power generation circuit and is configured to (a) determine a structure-to-electrolyte reference voltage for the electrolyte and structure, and (b) adjust the cathodic protection current from the anode to the structure to maintain the reference voltage substantially the same as a set voltage.

Abstract: A novel cathodic protection system is provided that automatically controls and adjusts the voltage potential between an anode and a structure to protect the structure from corrosion. The cathodic protection system is self-powered, requiring no external power source or batteries. A cathodic protection circuit is configured to provide a cathodic protection current from the anode to the structure through an electrolyte. A power generation circuit is configured to generate power from a galvanic cell formed from the anode and an isolated electrode when cathodic protection is interrupted. A voltage potential control circuit is powered by the power generation circuit and is configured to (a) determine a structure-to-electrolyte reference voltage for the electrolyte and structure, and (b) adjust the cathodic protection current from the anode to the structure to maintain the reference voltage substantially the same as a set voltage.

Abstract: Metallic structures located in an electrolyte, such as soil or water, for example, tend to corrode. In order to prevent metal loss from the structure due to corrosion, a D.C. current flow is created in the metal structure. This current flow causes a hydrogen ion film to form on the structure which insulates it from the electrolyte. The direct current is supplied to the metal structure by a combination of a solar array and storage batteries. During peak solar activity, the solar array both charges the batteries and supplies current to the metal structure. When the batteries are fully charged, the batteries are disconnected and the entire solar array output is applied to the metal structure. If solar activity decreases below a predetermined level, the batteries are switched back into the circuit to maintain current flow at a predetermined minimum level.