A switch-mode self-coupling power device additionally increases a set of high voltage auxiliary winding in the transformer and increases a control circuit and an energy transmitting circuit in the primary side circuit of the conventional circuit. The pouch includes a pair of opposing walls with a first half and a second half. The analog output signal has a ramp-up portion having a first shape, where the first shape corresponds to a piece-wise-linear approximation of a sinusoid. A tongue is supported in an intermediate part of the webbing so that the tongue can slide relative thereto. When the primary application server itself becomes unavailable, one or more of the backup application servers may be promoted to the role of primary application server. The slot has at least one enlarged portion at about at least one predetermined area of high stress concentration.