Abstract: A direct power output digital to analog conversion of digital audio signals operates to directly convert digital audio signals into an analog power audio output signal capable of driving a speaker, such that there is no need for further amplification or modification of the audio output signal after the direct power output digital to analog conversion of the digital audio signals. The direct power output digital to analog conversion incorporates a digital-to-analog converter within the same feedback circuit as a current-to-voltage power amplifier by using a single resistive feedback network to supply the feedback signal from the output terminal of the current-to-voltage power amplifier to the summing junction of the same current-to-voltage power amplifier.

Abstract: A method and system is provided for a digital audio system to reconstruct a digital audio signal using time domain interpolation and direct power digital-to-analog conversion. A signal processor performs the time domain interpolation on an original digital audio signal to allow for the proper recreation of the original audio signal and a direct power output digital-to-analog converter generates an analog power audio output signal from the interpolated digital audio signal that can directly drive a speaker to produce the sound waves represented by the audio output signal. The signal processor and direct power output digital-to-analog converter allow a digital audio system to more precisely reconstruct an analog power output audio signal from a digital audio signal such that there is no need for further amplification of the audio output signal and such that there will be no perceptible difference between the reconstructed digital signal and the original analog signal.

Abstract: The data telemetry system disclosed is a complete data communications systems suitable for use by utilities such as electric companies, gas companies and water companies which can be used for meter reading and load management at individual subscribers premises. Elements of the system can also be used as a power load carrier in a premise specific local area network (LAN). With the system is disclosed, all 10,000 subscribers per exchange can be serviced. It will be understood that data can be multiplexed between a central office location and remote subscribers for any suitable purpose with the data system as disclosed. A packet switching structure is disclosed having eight to thirty-two bytes in the data message. This packet is routed between the utility and remote subscriber with routing headers being added and deleted as required by the network modules. Each successive layer of the multiplexing and switching hierarchy submultiplies the aggregate 10,000 channel capacity into fewer channels.

Abstract: Lipin particles are removed from aqueous suspension by adsorption on hydrophilic macromolecules substituted with pendant hydrophobic groups. Particularly beneficial results are achieved by use of pendant hydrophobes linked by strongly ionogenic groups to water insoluble carriers.

Abstract: A microporous filter having pleated filter cartridge is provided with inlet and bypass ports for establishing tangential flow across outside boundary of cartridge inlet side resulting in slow clogging operation.