DE1766686C - Circuit arrangement for identifying a ground beacon on board - Google Patents

Description

Peak detector 14 supplied, which has an output signal for the excitation of a gate circuit (gate 16) supplies, when the output of the filter 12 exceeds a predetermined level. If the gate 16 is excited, it couples, for example, a power supply (not shown) to an oscillator 18, the oscillates at a frequency of 1350 Hz, which puts the latter into operation. The exit of the oscillator 18 is amplified by an audio amplifier 20 and through an output transformer 22 to the audio frequency system of the aircraft, for example the headphones 24 of the pilot.

When the height of the 1350 Hz component of the square wave drops below a preset level causing the filter output to fall below that from the peak detector 14 falls, the gate is activated

16 de-energized and the oscillator 18 switched off

The result of the system according to the present invention is that the pilot receives an audio frequency signal constant amplitude, at which the influence of the noise has been eliminated.

When speaking, the signal is less unpleasant and irritates the pilot less, so that the pilot becomes more aware can concentrate on his other tasks.

1 sheet of drawings

Claims (1)

l 2 "· * To form, namely Ve seconds for a point and. · Patent claims: Va seconds for a dash. In earlier TACAN- '"-' Systems, the incoming pulses were _{fed to a T} , 1. circuit arrangement for identification 1350-Hz-Hlter, whose output signal a • a ground radio beacon, which reached a point dash 5 certain amplitude, as soon as such Im identification signal, whose points or dashes pulse were received. The output signal of the repetition frequency filter given by series of pulses was then amplified and fed to the sound system, sent out, fed on board by generating the aircraft, normally that of acoustic signals from the corresponding headphones of the pilot. Although this system leads to the desired result when the impulses are received, this system leads to the desired result, but all noise is characterized by changes in the circuit, which are fed into the receiver circuit (10) to lengthen the impulses with a square wave, processed and amplified by a sound, which leads to an undesirable arrangement (12, 14) for generating a th additional audio frequency signal in the head electrical signal, the amplitude of which leads to the height of the listener, from which the pilot cannot escape, the component of the Square wave from Since, in addition, the mean amplitude value corresponds to the given frequency, the filter output can change due to the noise level or the like equal to the amplitude of the electrical signal, the tone amplitude also changes at a predetermined level and for generating the the pilot has to adjust.
20 The present invention has the task of improving this given level by means of an audio frequency signal system known in such a way that the pilot lator (18) and a gate circuit (16) that control the aircraft through the noise signals audio frequency oscillator is less annoying when the control is present. This is achieved according to the invention signals to the associated supply voltage connected by a circuit arrangement for extending the source, the audio frequency oscillation 35 pulses to a square wave being used by a gate as a source for the acoustic signals. Circuit arrangement for generating an electrical 2. Circuit arrangement according to claim 1, see the signal, the amplitude of which corresponds to the height of the com 30 of the electrical signal with a specified pevibrator and the circuit arrangement (12, 14) gel and for generating a control signal when the square wave exceeds the specified level, through a tone-speaking electrical signal except for a frequency oscillator and a gate circuit that controls the filter (12) comprises a detector (14). Audio frequency oscillator when the control 3. A circuit arrangement according to claim 2, da- 35 signals to the associated supply voltage through characterized in that the multivibrator (10) connects source, the audio frequency oscillator is dimensioned so that the positive and the negative serves as a source for the acoustic signals. tive half-waves of the square wave.A gated oscillator is used accordingly. are long. det to produce a clean tone for the 4. Circuit arrangement according to claim 1, 2 40 headphones of the system, wherein the input noise or 3, characterized in that a level or the like cannot affect the sound, stronger (20) is provided for the audio frequency. The oscillator is switched on when an amplitude detector determines that the filter output has reached a usable height. To the generation 45 of the square waves, a monostable The invention relates to a circuit multivibrator used from its output arrangement the desired frequency is filtered out to identify a ground radio signal. Infeuers, the one point Sirich identification signal, follow the use of a gated oscillator instead Dots or lines from a series of impulses result in a constant amplitude of the audio frequency given Repetition frequency consist, transmits, at 5 ° signals. Board by generating acoustic signals of the In the following, the invention is based on the in corresponding dot-and-dash pattern when receiving the drawing as a schematic block diagram. the impulses. provided embodiment explained in more detail Such ground beacons will be in for example. a flight navigation system known as SS As shown in the drawing, a one-TACAN is used. In this system output signal to a monostable multivibrator 10, the position of an aircraft is determined, guided by each pulse of the signal that the distance and the bearing of the aircraft is triggered and a square wave is generated, the pulses of which are calculated in addition to a ground beacon. So that they have a duration that half the distance of each ground beacon can be individually identified is ⁶ ° between the impulses of the signal. The can, it periodically sends out a signal consisting of a rectangular wave output of the monostable multivibraciner sequence of dots and lines, the gate 10 is fed to a filter 12, tuned to are coded to identify the 1350Hz in question, preferably a filter from the radio beacon. The dots and dashes are of the twin "T" type, whereby the square wave is filtered with a 65 series of closely spaced pulses and an output is generated with a pulse repetition rate of 1350 pulses per second, height representative of the height of the 1350- Hz-Komwclchc pulse train during different time components of the square wave.
perioucn is sent to dots and dashes The output of the filter 12 is a