Disclosed is a system for providing an external electrical power supply to a proximity smart card for driving the internal electronics of the smart card. The ECMS features a \u201csoft start\u201d that ramps the electric current from zero to full current over a two second period of time. The engaging portion defines a recess. A first path condition and a second path condition for one or more corresponding paths is determined such that one or more corresponding basic blocks return a constant Boolean value of true for the first path condition and a constant Boolean value of false for the second path condition. In the device, a gradated display corresponding to the ratio of the division can be obtained by time-sharing the signal during a write-in of time t without changing the time F.