Abstract: Any physical methods logic circuit design is based on using formal models of gates and wires. The simplest model of a gate is determined by only two parameters: (a) Boolean function is to be calculated, (b) fixed propagation delay. The simplest model of a wire is an ideal medium with zero resistance and consequently, with zero delay. In this study we propose an approach based on the physical nature of transitions in CL, using this idea for the design of speed independent ripple carry adder. We believe that each transition is actually a transfer of energy which can be naturally detected by physical methods.