A RAM circuit has a memory cell array whose number of rows is an integer multiple of an integer p>1 and is composed of regular and redundant rows. Examples of hydrophobic monomers include N-vinyl caprolactam, vinyl acetate, vinyl esters, acrylated glycols, methacrylamide, C1 to C12 alkyl- and C1 to C12 dialkylacrylamide, C1 to C12 alkyl- and C1 to C12 dialkylmethacrylamide, C1 to C12 alkyl aery late, C1 to C12 alkyl methacrylate, 4-butyl phenyl maleimide, octyl acrylamide. The coupling system has a first configuration configured to transfer electrical energy to the first energy storage device via the bi-directional DC-to-DC voltage converter, and has a second configuration configured to transfer electrical energy from the first energy storage device to the voltage inverter via the bi-directional DC-to-DC voltage converter.