Lord Corporation

David J Hamo

David M Catanzarite

John C Holzheimer

A Class-D amplifier using an audio signal input structure with monolithic devices forming integrated circuit configurations to receive audio input signals to be amplified. One monolithic device used to couple audio input ports to receive respective audio input signals to be amplified and feedback network to receive feedback signals is a pulse-width-modulator. Another monolithic device is used to form an integrated circuit with a pulse-width-modulated square wave input ports. Field effect transistor driver circuits are connected to respective pulse-with-modulated square wave signal input ports. Filter circuits coupled to the integrated circuits are used to receive and filter the amplified square wave signals and produce continuous amplified audio signals.

Class-D amplifier input structure

A method for automatically calibrating a controller (44) for a controllable damping system (40), for example, the suspension and damping system for a truck seat or cab, includes the steps of receiving a initiation signal that is checked against criteria to ensure that calibration is actually intended. The seat (20) or other body (ex. a vehicle cab) is then moved to a first limit position, where a sensor (50, 50') reads a position signal, and to a second limit position, where another position signal is read. Preferably, a midpoint, or neutral position is calculated from the measured position signals, and the seat (20) or other body is moved to this neutral position. A range of movement is determined from the first and second position signals. Preferably, end stop limits are calculated as predetermined fractions of the range of movement value. All values are stored for use by the controllable damper system (40).

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Cary, NC, United States of America

David J Hamo