Programmed audio controller
December 18, 2007. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 2489008 3073041 3493681 Transistor switches for selecting program signals in a wired broadcasting system Multiple input signal digital attenuator for combined output Miniaturized scan within a pulse sonar Methods and apparatus for transmitting electromagnetic radiation for illumination and communication Programable low impedance digital attenuators Balanced impedance coupler Audio distributing system InventorApplicationNo. 861088 filed on 05/08/1986US Classes:381/81With switchingExaminersPrimary: Isen, Forester W.Attorney, Agent or FirmForeign Patent References
International ClassH04B 003/00AbstractController for use at a listening station in an audio distribution system for selecting a channel of audio programming. The controller has input attenuators for reducing the level of the audio signals, an output amplifier, and a controlled analog switch connected between the attenuators and the amplifier for passing the attenuated audio signal from a selected channel to the output amplifier. The amplifiers have a relatively high imput impedance, and the amplifiers in the distribution system operate at a relatively low power level. The attenuated audio signals are impressed upon a voltage centered in the operating range of the analog switch. In the disclosed embodiment, the analog switch comprises a multiplexer, a counter connected to the address inputs of the multiplexer, and a channel selection switch for applying clock pulses to the counter to step the multiplexer through the audio channels in a predetermined sequence.Other References
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