Abstract: This invention discloses a DME which employes an improved technique for validating received replies. The technique employed reduces lock-on time by analyzing all of the range data received within a set time period following the transmission of an interrogation pulse pair rather than just one range figure for each interrogation cycle. The DME also provides improved accuracy and reliability by varying the width of the range gate used in analyzing the received range data in accordance with the time difference between the two interrogation cycles from which range data is being compared with system status, i.e., whether the system is in the locked position or not.

Abstract: Disclosed is a method and apparatus for adjusting the gain in a weather radar receiver to correct for precipitation induced transmission path attenuation. The receiver gain is controlled in a known manner to accommodate known path transmission effects. The gain controlling apparatus comprises fixed and variable AC resistances, where the variable AC resistance is an attenuator diode driven by a varying current source. The variable current source provides an approximation to a hyperbolically decreasing current when no video returns or echoes are present. However, upon sensing the existence of a video return indicative of rain at a moderate intensity, a portion of the charge on the RC networks in the current generator is shunted to ground, increasing the rate of change of current provided by the current source. This modification of the attenuator substantially reduces attenuation-induced receiver errors present within the sensitivity time control (STC) interval.

Abstract: A connecting device for use in a visual display unit to electrically connect a pair of substrates with one another and with a printed circuit board. The device includes a body portion for insertion into a socket or hole of the printed circuit board, a transverse bar providing a seating surface for engaging the board, and a pair of contact elements which are urged by spring action against conductive strips on the substrates.

Abstract: This invention relates in general to a universal frequency synthesizer which is suitable for use in a phase-locked loop frequency synthesizer system comprising a voltage controlled oscillator, a reference oscillator and a low pass filter. The universal frequency synthesizer of the present invention is basically comprised of programmable divider circuitry and a phase detector.The universal frequency synthesizer is arranged to receive tuning data in serial format from an external source. The received tuning data is permanently stored within the universal frequency synthesizer and is used to establish the division ratio by which the output signal produced by the synthesizer's attendant voltage controlled oscillator and the reference signal produced by the synthesizer's attendant reference oscillator are divided before being provided to the signal and comparison inputs of the phase detector, respectively.

Abstract: The disclosed deviation driver circuit is capable of producing a difference voltage having a magnitude related to the voltage of a deviation signal provided to the circuit from an external source. The deviation driver circuit of the present invention is comprised of a differential amplifier with negative feedback. This differential amplifier includes a pair of transistors and a plurality of load resistors which are arranged to form a balanced bridged network. Since one input of the differential amplifier is electrically connected to ground, this amplifier generates a difference voltage having a magnitude related to the voltage of the signal provided to the active input of the amplifier. The feedback loop, on the other hand, includes another differential amplifier which is interconnected with the first mentioned differential amplifier to produce a feedback signal having a voltage level related to the magnitude of the difference voltage produced by the first mentioned differential amplifier.

Abstract: A tool for handling integrated circuits to facilitate their installation on and extraction from circuit boards. A pair of spaced apart levers are pivotal about integral hinges in a manner to engage opposite ends of the integrated circuit. Each lever carries a pair of lugs between which the ends of the integrated circuit are gripped. The opposite end of the tool is constructed similarly although with a pair of levers that are closer together in order to handle a smaller integrated circuit.

Abstract: A single crystal controlled oscillator provides clock pulses that are used to drive both the decoder shift register and the encoder shift register of an ATC transponder. An input pulse of the interrogation signal from a ground station is shifted down in the decoder shift register and is time correlated with a subsequent pulse of the input signal to verify the validity of the interrogation. A valid interrogation signal triggers gate logic circuitry which loads data into the encoder shift register. The clock pulses from the oscillator are processed to the appropriate frequency for driving the encoder shift register, which outputs serial data for transmission as a coded reply signal responsive to the interrogation signal. The decoder shift register and cooperating edge trigger coincidence gate circuitry suppress side lobe interrogation signal and inhibit operation of the transponder when same are present.

Abstract: A switch structure detects acceleration in a preselected direction such as, for example, along the pitch axis of an aircraft. The switch has a spring supported mass urged toward a stable centered position within the switch housing. Acceleration displaces the mass such that it trips a spring wire switch mechanism for controlling such avionic devices as the autopilot system of the aircraft. A pair of solenoid coils are wound around the spring mass system on opposite sides of the centered position of the mass. The switch may be preflight tested by successively energizing the solenoid coils to attract the mass toward the centers of the solenoid fields, thereby artifically displacing the mass against the spring wire switches.

Abstract: A pressure transducer includes an electromagnetic drive coil which vibrates a thin walled cylinder at a natural vibrational mode. A capacitor unit senses the vibrational frequency of the cylinder and gives an output signal corresponding to the pressure differential between a fluid contained within the cylinder and a vacuum reference that is maintained adjacent to the exterior surface of the cylinder. Electric heaters maintain a constant operating temperature of the transducer.

Abstract: A command bar gives pitch and roll commands to an aircraft pilot. The command bar is carried on a magnet assembly which is supported to pivot on a pair of perpendicular edges that correspond to the pitch and roll axes. A permanent bar magnet included in the assembly has its opposite ends received within bobbins on which coils are wound. The coils are arranged in a plurality of separate tiers located above and below the ends of the magnet. Fields are generated by the coils to selectively deflect the magnet in a manner to effect pitch and roll movement of the command bar.

Abstract: An automatic data input/output system has combined card reading and recording device features which permit a pilot to totally utilize same as part of an aircraft navigation system. A small light weight drive system is incorporated within the device to move the magnetic card with respect to the read-write heads.The operational modes of the system include a MONITOR MODE, a RECORD MODE, an ENTER MODE, and an ERROR MODE. This permits a pilot to encode or record navigational data on a magnetic card or read the data from the card and automatically input same to a device for assisting in the navigation of the aircraft. The ERROR MODE provides a means for checking the data as read from the card to insure the accuracy of same before it can be used by the navigational device.

Abstract: A transistorized active switch radar pulse modulator has a unique means for pulse current control which includes a transformer interconnected with a magnetron. Transistor switches and related circuitry pulse a step up transformer with voltage pulses to drive the magnetron with a desired current pulse having the appropriate shape and width. A capacitor in the secondary of the transformer acts as a load to the transformer prior to the conduction level of the magnetron so that no current transients occur after the magnetron fires. Suitable protective features operate to sense an arcing condition and to dissipate the arcing effects. A unique slope control circuit insures that the requisite flat current pulse drives the magnetron.