DE3344750A1 - DEPTH SENSOR - Google Patents

Description

DORNIER GMBH

7990 Friedrichshafen

Reg. 2526

Depth sensor

The invention relates to a depth sensor for sea mines, Torpedoes or underwater projectiles equipped with an acoustic transducer for detecting targets are. For the ignition decision, the ignition mechanisms - or the weapon computers - need the information of the respective current water depth.

Depth sensors are known, which derive the static from the deformation of an elastic element (can, membrane or spring) Display pressure and thus the water depth. The measurement signal is usually supplied as an electrical quantity. The depth sensor is a separate component that makes the overall system more expensive and takes up space in the warhead and capacity of the on-board battery are required.

The object of the invention is to create a depth sensor that is inexpensive and small, which requires little power and reliable over a long period of time with an accuracy of

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approx. - 0.1 m works.

According to the invention, this task is carried out by a depth sensor solved with the features mentioned in the claims.

The depth sensor according to the invention uses that in the piezo crystal of the hydrophone caused by the water pressure charge shift, creating free charges at the interfaces appear. The voltage corresponding to the water pressure is applied via a high-resistance amplifier (charge amplifier) Electrodes tapped and fed to further processing electronics in the weapon computer. The utilization of the direct voltage component of the hydrophone saves a separate, separate component for depth measurement.

The query of the depth information (= measurement of the charge displacement) can take place periodically, the first being Measurement indicates the absolute depth. This is stored, the charge on the crystal is discharged with low resistance. If the depth of a mine at the bottom of the lake does not change, there will be no shifting of the cargo with the next query ascertain. If, however, charge shifts occur, then their sign indicates a further decrease or on a rescue attempt, to which the computer can react accordingly.

The query period is for moving projectiles or " Torpedoes set much higher, e.g. B. every second,

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than mines (hourly to daily), which have a long lifespan with relatively small changes in depth. The depth sensor can be equipped with an automatic system which, in the event of larger pressure changes (depth changes), e.g. B. switches on the computer due to overvoltages, which is usually switched off to save battery capacity. For projectiles or torpedoes, for. B. also used the piezoelectric impact sensor as a measuring device for the depth will.

Further advantages, features and areas of application result from the figure described below.

The figure shows a block diagram of a hydrophone circuit which also serves as a depth sensor for a sea mine. In the mine housing 2 there is a piezoelectric hydrophone 4 directly on an outer wall, which is operated via a crossover 8 and an amplifier 10 electrical alternating signals, which correspond to the ambient noise, to the listening input 12 of a weapons computer 14 supplies where the signals are analyzed according to intensity and frequency spectrum. Of the Computer output 16 leads to the ignition mechanism. According to the invention, the piezoelectric hydrophone 4 is also used for measuring the Depth used. For this purpose, a computer-controlled switch 6 and a are in the DC voltage output 18 of the crossover network 8 high-impedance amplifier 20 is provided.

After a preprogrammed time after the mine 2 has been dropped, the computer 14 closes the switch 6. That of the charge The output signal of the amplifier 20 corresponding to the piezo crystal is stored in the computer 14. The crystal will then discharged (a device for this is not shown).

Later measurements, which take place according to pre-programmed times, register every change in depth, the greater than - 0.1 m.

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Claims (4)

DORNIER GMBH Friedrichshafen Reg. 2526 Patent claims: "N.". · ■
/ 1 . Depth sensor for sea mines, torpedoes or underwater projectiles, which have an acoustic transducer for sound recording, characterized in that a high-resistance amplifier (20) is coupled to the acoustic transducer (4) with a DC voltage (8). 2. Depth sensor according to claim 1, characterized in that the acoustic transducer (4) is a piezoelectric Hydrophone or a piezoelectric impact sensor can be used. 3. Depth sensor according to one of the preceding claims, characterized in that the depth signal is periodic is queried, whereby the charge in the hydrophone (4) can be deleted after each measurement. 4. Depth sensor according to one of the preceding claims, characterized in that a voltage signal is the Computer (14) of the weapon switches on automatically.