A power system that increases the power capability of a DCAC converter includes a processor coupled to the DCAC converter and a memory subsystem coupled to the processor. An anti-jamming system determines, during an adjusting operation, current adjusting force values at least within a partial area of the adjusting path and respectively, in predetermined positions of the closing part, and compares the values to adjusting force comparative values which are already stored in a storage device. A time-frequency transform is applied to the data to produce a series of spectra. The pixel array is disposed within the display region. This application consolidates the various features previously disclosed in patent applications GB0418571. The projecting optical system has an aspheric toric surface.