Abstract: The impedance of ionic solutions may be determined using a bridge circuit where the ionic solution forms one leg of the bridge circuit and a reference impedance characterized by a reference time constant forms a second leg of the bridge circuit. The bridge is driven by a switched DC voltage waveform. Measurement of the ionic solution is delayed after switching to allow the reference impedance to reach its asymptotic value. The reference impedance may be varied to reduce the reference time constant.

Abstract: The impedance of ionic solutions may be determined using a bridge circuit where the ionic solution comprises a leg of the bridge circuit and a reference impedance characterized by a reference time constant comprises a second leg of the bridge circuit. The bridge is driven by a switched DC voltage waveform. Measurement of the ionic solution is delayed after switching to allow the reference impedance to reach its asymptotic value. The reference impedance may be varied to reduce the reference time constant.

Abstract: The invention is directed to an improvement in mechanisms and techniques for accepting user input. An apparatus for accepting a user input is described comprising a display, and a plate and a control knob positioned over the display. A portion of the display is visible through the plate, and a portion of the control knob is optically transparent such that information displayed by the display is visible through the control knob. In some examples, the control knob functions as both a rotary input and as a push button input. The control knob may function as a push button input through a transfer of force through the plate to a pressure sensing switch associated with the plate. The control knob may function as a rotary control through drive gears, belts, or interaction with a light emitter and detector.

Abstract: An apparatus and method for programming a universal remote control. The method includes receiving a transmitted signal of unknown modulation technique from a native remote control and characterizing the received signal in parameters of a pre-determined modulation technique.

Abstract: The invention is directed to an improvement in mechanisms and techniques for accepting user input. An apparatus for accepting a user input is described comprising a display, detector and controller. The display is configured to show an initial output. The detector is positioned in a location with respect to the display such that the detector detects placement of a trigger, such as a user's hand, proximate to the display. Various methods of detection such as infra-red detection, ultrasonic detection, capacitive detection, etc. may alternatively be used. The controller is configured to, upon placement of the trigger in a relative position with respect to the detector, cause the display to display an alternative output. After a pre-determined period of time, the display automatically reverts to the initial output or similar reduced-content output.

Abstract: A control mechanism includes an optically transparent member, a knob with a reflective surface, an optical light source, and an optical receiver. The optical light source directs light toward the knob that is reflected to the optical receiver.

Abstract: A radio receiver has a radio tuner having a radio frequency input and an audio output, and an audio signal amplifying system having an audio input and an electroacoustical transducing output. A volume controller is coupled to the radio tuner and the audio amplifying system. A microprocessor is coupled to the tuner, volume controller, a visible display and an array of controls.