Abstract: A Class-D audio amplifier is disclosed which accepts a digitized audio signal input and drives a load such as a loudspeaker without digital-to-analog conversion. The amplifier preferably comprises (1) means for processing a plurality of digital audio input values to create a plurality of deviation values respectively based on the deviation of the input value's relationship from a previous audio input value, (2) means for producing a carrier signal, (3) modulation means for using the deviation values to responsively modulate the carrier signal by varying the frequency of its waveform inversely with the magnitudes of the deviation values, and (4) filter means operative on the modulated carrier to produce an analog voltage capable of driving the load.

Abstract: A tissue dispenser is disclosed which permits a user to choose from a variety of liquids to be sprayed on a tissue prior to dispensing. To prevent the tissue from dissolving or becomes too wet to handle comfortably, the dispenser folds the tissue into a double layered structure prior to spraying with the selected liquid, and sprays one layer of the two-layer structure just prior to dispensing so that the dry layer can support the paper's shape and enable the user to handle the tissue without tearing it.