Airdata Inc.

Foster Airdata Systems Inc.

Other

Foster Bio Technology Corporation

George B Foster

Paul Douglas Gibbs

Thomas L Fletcher

Michael A Smyser

David E Harris

Electrobiological stimulation is carried out transcranially by applying high frequency squarewave bursts exhibiting no d.c. term across the cranial region. Such stimulation is commenced employing ramp generators and positive and negative voltage converters which evolve the requisite baseform and burst frequencies having a voltage waveform which is square in nature. Both voltage and current are sensed and subjected to comparator logic in conjunction with predetermined thresholds and windows. Overcurrent detection and overvoltage detection is provided in hard wired fashion to assure rapid shutdown response. D.C offset detection is provided along with waveform balance tests to further assure the safety of the system. Diagnostic procedures as well as therapeutic procedures may be carried out with a system version which provides for the application of a stimulus in conjunction with safety monitoring and controller based development of stimulating waveforms, all of which exhibits no d.c. term. Feed point voltage waveforms and current waveforms are mathematically processed and compared for diagnostic analysis.

Electrical stimulation of tissue for therapeutic and diagnostic purposes

An area navigation device automatically establishes waypoints along an RNAV course line intersecting with the four cardinal radials of VORTAC stations. For a given VORTAC station, the pilot selects any of the four cardinal radials and is automatically provided with the distance from the VORTAC station, along that cardinal radial, as the intersection with his selected RNAV course line. Thus, a pilot can quickly sequence through the cardinal radials and quickly ascertain the availability of waypoints along that radial. After an automatically generated cardinal waypoint is selected, it is automatically entered into memory dedicated to that waypoint for later recall and conventional use in area navigation.

Automatic waypoint area navigation system

Face plate and controls for an aeronautical radio navigation device

An arrangement for preventing inadvertent transmission by a push-to-talk transceiver that might join a communications channel. After the push-to-talk switch has been activated, an average background noise level is established. Audio from speech, for example, having peaks greater than a predetermined percentage of the average background noise level are required to maintain the push-to-talk function activated.

Transmit/receive mode protection arrangement

In a communication system wherein multiple radio stations communicate with one another over a single channel, an arrangement for indicating to a first user who is transmitting over the channel that there is a simultaneous transmission occurring on the channel by another user, possibly blocking or interferring with transmission by the first user. The arrangement includes means for periodically causing the transmitting first radio station to reduce its transmitting power, listen for a simultaneous transmission on the channel by another station, and then resume full transmitting power. The detection of a simultaneous transmission is annunciated to alert the first user that his transmissions may have been interferred with. Interruption of the first user's transmission may occur either periodically or at detected pauses between the first user's spoken words. The arrangement operates in conjunction with the conventional automatic gain control circuit of the first user's station.

Simultaneous transmission signal detection system

There is disclosed an area navigation system including signal averaging and lag compensation circuits to overcome VOR signal propagation instabilities and a meter sensitivity control circuit which decreases the sensitivity of a track angle deviation left-right needle display as the aircraft approaches a waypoint. Means are also provided for digitally displaying the aircraft bearing to the waypoint.

Area navigation system

An area navigation system capable of operating during an ILS approach to provide the pilot range and bearing with respect to the outer and middle markers for a front course approach, and with respect to the final approach fix and the end of the runway for a back course approach. The system operates by automatically connecting the # 2 NAV receiver to the RNAV during ILS operation while the ILS localizer converter is connected to the # 1 NAV receiver. At the same time the RNAV is disconnected from the left side indicator so this may be used for the localizer.

Approach range monitor

There is disclosed a vertical guidance computer for general aviation aircraft operating in conjunction with an area navigation system to convert data representing the range from the aircraft to a runway or other target into a measure of the altitude at which the aircraft should be for a given descent rate. Means are provided for adding a correction representing the mean sea level altitude of the runway, and for pre-establishing an adjustable minimum descent altitude. When the range corresponding to the minimum descent altitude is reached, an appropriate warning is given. The system utilizes a time analog of range data and a scaling of the basic system clock in accordance with the desired glide slope or descent rate. The scaling is such that the number of cycles of the scaled clock directly represents the command altitude in feed above mean sea level.

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Worthington, OH, United States of America

George B Foster