DE2038733C - Device for determining the initial velocity of a projectile - Google Patents

Description

according to claim I. characterized in that a distance from one another arranged and \ oi the Ge-Thcrnu> »uk <Mand (/? r»> on the measuring transducer (S, /.,. shot through flown measuring coils, in soft at L.) is arranged and that the passage of the projectile measured on it is generated a pulse

pensalionsspannungfi / tf) is used, the ao 370 582 known device of this type are the on the part of an electronic compensation circuit measuring coils carried by rods, which rods (Λ7Ί is fed. Again at the mouth-side end of the channel

i. Circuit arrangement for a device nonenrohres yeast,! Igt are and beyond this end according to claim 2, characterized in that they protrude. The electronic compensation circuit (KP) heated by the hot powder gases has a cannon barrel and the inverter (NV) from the barrel of the cannon, to which the muzzle flashes which occur the measuring pulses cause high temperatures that the output of the inverter (/ VK) fluctuations on the rods and measuring coils of the with the input of a modifi. '^; erten, monostable encoder. When in shooting operation usually on toggle switch (MMF) is connected. whose temperature differences of more than 500 C are made in such a way that, as a function of the length changes in the measuring section between the two supplied compensation voltages (Uk), the measuring section has been determined, which changes the duration of its quasi-stable state, in which Of the order of almost 1 ° / ₀ . Since the input (E) and output (B) of the mood of the initial velocity of the projectiles modified, monostable flip-flop (MMF) under the prerequisite of an unchangeable measurement in each case on first inputs of UN D levels ( U ₁ , 35 stretch on a pure time measurement is based, the U ₂ ) is carried out that the second inputs of the change in length of the measuring section in the known case AND stages (U ₁ , U ₂ ) with the two outputs fully as an error in the measurement.
(G ₁ , C ₂ ) of a bistable flip-flop circuit (FF) The present invention aims to avoid these Nachbunden that the outputs of the two AND part. According to the invention, this is achieved because stages (i / "IZ ₂ ) via an OR stage (O) to 40 through that a device for compensating the temperature-dependent change in distance of the measuring (MF) at the input of a monostable toggle switch is performed, which monostable toggle switch - Coils is arranged.

device at its output (A) the corrected measurement

outputs pulses, and that the corrected measuring the F i g. 1 to 4 illustrated embodiments pulses on the symmetrical input of the bi- 45 explained in more detail. It shows:
stable trigger circuit (FF) are fed back. F i g. 1 the arrangement of a transducer on a

4. Circuit arrangement according to claim 3, da- cannon barrel,

characterized in that the base of a F i g. 2 shows a diagram of a circuit arrangement for

Determine the velocity of the bullet with a normally conductive state

TrBuSiStOrS (Q ₄ ) of the modified, monostable 50 compensation device,

Flip-flop (MMF) to a constant current F i g. 3 the signal course is connected to characteristic generator (Q ₃ , R ₁ , R _s , D ₃ -D ₆ ) and points of the circuit arrangement,
that the collector of a normally in Fig. 4 a detailed, circuit-like lock-out state located transistor (Q ₃ ) guidance of the compensation device,
other compensation voltage (U _K ). 55 According to FIG. 1 are on a flame arrester

5. Circuit arrangement according to claim 2, there funnel FT of a cannon barrel K three rods S rigidly characterized in that the thermal resistor is attached. The rods S carry near their ends (Rth) in the input circuit of an operational amplifier two measuring coils L ₁ , L ", which are made of insulated wire (OPJ , and that consist of rings wound in the feedback loop and through which a branch of the operational amplifier ( OP ₂₎ a non-60 the gun barrel K escaping projectile G hinlineares network (KL) is arranged able, by flying thereby. on one of the three rods S, the gain of the operational amplifier is a thermal resistance Rt * mounted as a probe, in accordance with the nonlinearity of the thermal Electrical connections AS for the measuring coils L ₁ , L \ resistance and the non-linear correlation and the thermal resistance Rt * are accommodated in one of the three rods S between the change in distance between the measuring 6s.

coils (L ₁ , L ₁ ) and the change in temperature. 2 are the two measuring coils L ₁ , L \

iidert. connected in series, and the primary winding of one

6. Device according to claim 1, in which the transformer T is in turn in series with the two

3 4

the measuring coils L ₁ , L ₂ . A stabilized direct current prevailing temperature at the measuring section and the source / ,, feeds the series circuit, consisting of the change in length of the same. The output of the transformer T which supplies the variable compensation voltage Uk which is analogous to the two measuring coils L ₁ , L ₂ and the primary winding. The two connections are the output of the operational amplifier C. is on the modikundärwickung of the transformer T are on the 5 ficated, monostable flip-flop circuit ΜΜΓ , both inputs of an operational amplifier OP ₁ in connection with the pulse pattern after leads. One input of the amplifier and thus the F i g. 3, the mode of operation of one end of the secondary winding of the transformer T circuit arrangement according to FIG. 2 explains: The ghost is connected to ground - the other input of the bullet triggers a pulse when it flies through the measuring coil L ₁ , via an input resistor Rb with the io as well as the measuring coil L ₁ , which is the other end of the secondary winding of the transformer - Connected to the operational amplifier T via the transformer T , and on the other hand it is given via a ker OP ₁ . After the pulse amplifier feedback resistor R _R with the output of the kung, the amplified pulse is connected to the pulse shaper amplifier. The ratio of downshift IF is given, which converts the unshaped input coupling resistance Ru to input resistance R _E 15 pulses into exact square pulses. In

determined in a known manner, the signal gain of the FIG. 3, the circuit at the point D removable vriSri .. · ,. r ».., Au.iguiipsigiuii ucs ομυι <ιι luiiMv ei - / τ iisgungssignui tier impiiisiormersiuie ir uurgcMcm. slictTs O! \ »vinl fed to a pulse shaper lh . The Impiilsansiiegsflanken> ». <Ei ^; -n depending on the, in the non-contoured input signal, a right-hand shape of the floor diameter and the measuring distance signal. Such pulse shapers are z. B. as 20 i would extend the time interval /, «*. As the MeU-Sihmitt trigger is well known in the literature. The square pulse emitted by the length of the route depending on the temperature pulse shape IF is changed, if a correction of the time is required an inverter NV is fed, so that the square ^ distance i _m * of the two measuring pulses is negated. The square wave treated in this way is initially negated to a modified monostable multivibrator signal at circuit point L) . The circuit MMF at circuit point E is negated, which will be described in greater detail later (FIG. 3) signal is the modifischriebcn. inputted This modified monostable ed monostable multivibrator MMF. multivibrator MMF is the other hand, the LAN one assigns the positive voltage \ 12 V the genänderung the measurement path proportional Koupen- digital "O" signal and the voltage of OV the sationsspannung U _K fed This Kompensation- 30 digital "/." - signal too, it is caused by the at circuit voltage U _K, depending on their size _pu nkt e appearing first ^ "-" / "-. flank the modieine change in Duration of the impulses generated in the monostable fied monostable multivibrator MMF from your multivibrator MMF the modified monostable Kippschal- issues. After a time r, the signal arising from the size of the application MMF continues to lead to a compensation voltage Ur. depends, input of U ND stage U ₁ led. The other toggles the flip-flop MMF back into its stable gangdei AND stage U ₁ is back to the output C _{1 in} a position in which it is connected to its "/," signal at its output bistable flip-flop FF. The issue. The signal curve at switching point B gang B of the modified, monostable multivibrator (FIG. 3) illustrates this process. The MMF leads to an input of a further AND stage ₄ c appearance of the / th signal at the switch point B is U ₂ . The other input of the AND stage U ₂ at the same time the AND condition for the AND stage U ₂ is met with the output G _{2 of} the flip-flop, since the flip-flop FF is initially connected to FF . The bistable flip-flop FF is also its output G ₂ emits »/.- signal. Thus built so that when the circuit is put into operation, the output of the AND stage U ₂ »/. Signal arrangement, the right output G ₂ digital» /. I signal 45, which is O via the OR stage outputs the input. The outputs of the two AND stages U ₁ , U _{2 of} the monostable multivibrator MF arrive and are led to an OR stage O , and their output from the stable state in which it "access is" with the input of a monostable toggle - Sends signal at the output, connected to the quasi-stable connection MF . The output A, the mono-state, in which it emits a stable multivibrator MF for a predetermined time T to the sym- 50 "O" signal at the output. After the time T metric input of the bistable flip-flop FF , the n.onostable flip-flop MF toggles again, and on the other hand it is back to the stable state with the input of a. The connected here at the off gate circuit T , which occurs between a gang A "/," signal toggles the bistable crystal oscillator QG and an electronic counter Z circuit FF into their other stable state, in which it is switched. ₅₅ the output C, "/.th signal and the output G ₂ To gain, the compensation voltage Uk emits" Ö "signal Because the output G ₂ now serves a further operational amplifier OP ₂ . The one emitting more "!" Signal is one AND condition. The input of the amplifier is connected to ground, the other is fulfilled for the AND stage U _1. The second AND-Be input is connected to a voltage divider, which is fulfilled when the negated measurement signal is present at the resistors A ₀ , Rb and a thermal resistor 60 circuit point E when the projectile passes through . The voltage divider R ₀ , Rb, äta through the second measuring coil L _x jumps again from "0" to "L" between the two poles of an operating voltage. Then U ₁ Ub is switched at the output of the AND stage. A signal output between the one input and also »/. This gets over. the output of the operational amplifier OP ₂ switched the OR stage O to the input of the monostable non-linear feedback network KL has 65 flip-flops MF, which thereby consist of stable diodes and allows a state in which it "/." -Signal at the output, considering the non-linearity of the thermal resistor in the quasi-stable state, in which it for the pre- and de "non-linear relationship between the given time T * 0" signals at the output, toggles.

5 6

After line T has elapsed, the output A of the base-emitter path of the transistor (/,. The

apparent »/.- signal the flip-flop FF, emitter of the normally conductive transistor Q ₄

so that it _{emits the /.- signal again at output G 1} , is connected to ground via a diode D and the KoI-

whereby the output state of the compensation gate of the same transistor Q ₄ lies over a resistor

circuit is restored. 5 stood R _n at \ 15V and on the other hand via the parallel

The pulses at the output A, their time switching off of a resistor R ₁₀ and a capacitor i, n now correspond to that of the measuring device C ₄ at the base of an npn transistor Q ₂ . The stretch of the prevailing temperature is corrected, open the base of the transistor Q _t is on the other hand and close the gate 7 ', so that from your quartz oscillator resistor R ₁₃ to 15V. The emitter of the Trantor QG within the opening time t _{m of} the gate T a io sistor Q _t is connected to ground, and the collector is with a certain number of pulses in the counter Z ge the common circuit point of diode D _x and reaches. The count of the counter Z is thus connected to a direct capacitor C ₅ , this common measure for the speed of the projectile. Switching point across a resistor R, with the

Long changes in the measurement path are made at the input terminal Q for the correction voltage Uh

Speed measurement compensated by ent- 15 is connected. The input terminal Q is the other

speaking of the ruling and the change in length over a contradiction R _t with the common

causing temperature is the leading edge of the switching point of diode D ₁ and capacitor C ₁

first measuring pulse connected to the Korrcklurzcit τ vcr-,

is pushed. The modified monostable multivibrator MMF

This correction time τ is proportional to the length and acts as follows: A change in the measurement distance at the switching point and independently of the negative impulse that occurs is differentiated and the projectile speed is differentiated. Therefore there is a length of time on the base of the transistor Q ₄ , whereby this exact correction is only blocked for a certain speed. The tension at the base of Transikeit. The accuracy of the correction remains in the forward direction Q ₄ , by leaps and bounds, is sufficient because the compensation voltage Uk of interest minus the speed range is relatively small. Saturation voltage of transistor Q _{1 more} negative. On-

The in the F i g. 2, framed by dashed lines, the capacitor C ₅ charges with the

Sation circuit KP is in the F i g. 4 shows in detail the stabilized collector current of the transistor Q ₃ um,

placed. It consists of the inverter NV, the modi so that after a certain time the transistor Q _x

fiertcn monostable multivibrator MMF, which is bi-30 again conductive and the modified monostable

stable toggle switch FF, the monostable toggle switch MMF back to its rest position.

circuit MF and the between the bistable toggle The time in which the transistor Q _{4 is} blocked. and since-

circuit FF and the monostable multivibrator MF with also the pulse duration at the output is because of the

switched gate stages U _x , U _t , O. constant current supplied by transistor Q ₃

The structure and mode of action of this compensation- 35 only depend on the size of the compensation span-

circuit are as follows: between ground and voltage Uk proportional.

Both poles of the operating voltage of j 15 V are connected to an emitter follower, consisting of an npn tranzwo block capacitors C ₁ , C ₁ . The insislor (? ₅ , whose base with the collector of the transiverter NV has an npn transistor Q _x , its stors Q ₄ , its collector with fl5V and its base on the one hand via a resistor R ₄ to -15V 40 emitter via a Resistor R _{xt is} connected to ground and, on the other hand, via a resistor Zf ₂ and a diode D ₇ to the collector of the transistor Q _4, a capacitor C ₃ , which is connected in parallel to it, is connected to the input terminal D at output B, which To drive trapped load.

gangsklemmc D the shaped measuring pulses are fed to the input E and output B of the modifiers. The emitter of transistor Q _x is connected to ground 45 th, monostable multivibrator MMF are then and the collector via a resistor A ₃ to -f 15 V via capacitors C ₁₃ , C ₁₂ and diodes D _n , D _n and a resistor Ä » in bulk. The normal to the base of an npn transistor ρ, the mono- time blocked transistor β, is conducted when a stable flip-flop MF appears . A resistance of a positive measuring pulse conductive, whereby the at R _t i connects the common circuit point before circuit point E Koflektors voltage of the so capacitor C ₁ , and diode O _u with the left Au * transistor Q _x abruptly to the ground potential gang G _{1 of} the bistable flip-flop FF. Likewise approximated. This negative potential jump is connected to a resistor Λ _Μ the common scarf a C-GIied, consisting of a resistor R ₉ transition point of capacitor C ₁₁ and diode D ₁₄ mi and a capacitor C ₄ , differentiated and via a right output G _{1 of} the bistable Kippschaltuni diode D ₁ and a capacitor C ₉ to the base 55 FF. The components C ₁₁ , D ₁₄ , R ₁₉ ; C _ia , D _n , A “forms an npn transistor Q _{A of} the modified mono- the gate stages IZ ₁ , IZ ₁ , O.

stable toggle switch MMF given. The tran- The 'emitter of the transistor Q ₉ is on a

sistor Qi is normally conductive. This is ensured by a diode D _n to ground, and the collector is on di

pnp transistor Q ₉ , the collector of which is connected to the base of the output terminal Λ . Furthermore, the Kollek

Transistor Q _{t is} connected and a stabilized gate of the transistor Q, via a resistor R _n ai Feeds control current into this. The emitter of the Tran · + 1SV is placed and a

sistor Q _x is connected to di across the parallel connection of two resistor capacitors C _n and a resistor R _n

if R ₁ , R _{9 were} at -HSV, the base was fed once through a base of an npn transistor Q _n *. The basis of the

Opposition R ₉ to ground and on the other hand via transistor Q _n is via a resistor R ₉₉ a Diodes D ₃ , D ₄ , D _% and a Zener diode D ₁ on HSV. 65 15 V, and the emitter of this transistor is a

The Zener diode /) supplies the reference voltage to ground. The collector of transistor Q ₉ is exercising

Base of the transistor ρ *. The diodes D "D" Dj korn- a resistor Rf, at ι 15 V and via a

compensate the temperature response of the Zener diode D ₁ and capacitor C ₁₄ at the base of the transistor Q.

which base is on the other hand over a contradiction R _v , on (15 V.

The pulses occurring at the output Λ of the monostable multivibrator MF are fed back to the symmetrical input of the bistable multivibrator FF . The symmetrical input of the bistable multivibrator FF has a series connection of a capacitor Cj or C ₁₀ with a diode /) _u or / J _1n , which series connection is led to the base of an npn transistor Q ₉ or Q ₇ . If ft ₁₇ , / ?, “are also arranged between the common circuit points of capacitor C“ and diode D ₀ or capacitor C ₁₀ and diode / J _1n and the co-lectors of transistors Q _n and Q ₇ , respectively. The emitters of the transistors Q _t , Q ₁ are connected to ground, and the collectors are connected to 15 V _{via opposing areas A n} , Λ, _5. The base of the transistor Qt is connected on the one hand to the collector of the transistor Q ₇ via the parallel connection of a resistor / ?, '' and a capacitor C ₁₁ , and on the other hand it is connected to 15 V via a resistor R _21. The base of the transistor is also connected Vcrblinden Q ₇ on the one hand via the parallel sound of a resistor R ₁₉ and a capacitor C ₇ to the collector of the transistor Q _t , and on the other hand it is connected ^{to 15 V via a resistor 1} ^. The base of the transistor ρ is also via a diode D _n and a resistor Rr _{x placed} at a sounding point U , at which a positive back pulse can be generated. The base of the transistor (7 ”is then connected via a diode /) and a capacitor C to a switching point // at which a negative auxiliary pulse can be generated. The common circuit point of diode D ₈ and capacitor C _n is also connected to the collector of transistor Q _e via a resistor R _lt .

With the help of the positive Rückstcllimpulses at Schalllings point U or the negative auxiliary pulse at the circuit point // before the start of a measurement, the transistor Q _{7 is} conductive or the transistor Q _t blocked, so that in any case when the measuring device is started, the output C ₂ , ie the collector of the right I ransislors ρ ₇ , »/.- has signal (0 V).

The bistable flip-flop FF and the monostable flip-flop MF otherwise have the known property that they flip into the other position when a blocking pulse appears at their input. While the new switching state is also stable with the bistable breakover sound FF until a new blocking pulse appears, with the monostable multivibrator MF the new switching state is only quasi-stable, i.e. the monostable multivibrator resumes its old switching state after its own time constant T has elapsed.

In summary, the following mode of operation of the compensation device according to FIG. 4:

The uncorrected measuring pulses are applied to the circuit terminal D and reach the base of the transistor Q ₁ operated in the emitter circuit. The transistor Q _t inverts the input signal so that the measurement pulses appear negated at its collector. The negated measurement pulses that occur at the output /: 'of the inverter are applied to the base of the running transistor Q _{x of} the modified monostable multivibrator MMF , which causes it to tip over and assume its quasi-stable state. The duration of the quasi-stable state is dependent, in the manner already mentioned, on the magnitude of the tcmpcraUir- dependent compensation voltage Uk.

After the time expires, the modified mono takes; stable multivibrator MMF returns to its stable state, in which the right transistor Q _x Slrom leads. The collector of this transistor is thus approximately at 0 V, which corresponds to the digital »/.- signal. This /. Signal appears unchanged at output B. As already mentioned, before the start of the measurement, a reset pulse or a Milfs pulse ensures that the right transistor Q _{7 of} the bistable trigger circuit / V

ao is in the conductive state. Thus the right output G _{1 of} the bistable multivibrator FF also outputs »/.- signal (OV), whereby the gate circuit C ₁ J. R ₁ D _1x is prepared in this way. that the published and after the time at the output B of the modified one-shot MMF led to the gate stage "0" - "/.*-! Edge of the pulse occurs after: r differentiation reaches the base of the transistor Q _{a of} the monoslabile multivibrator MF . The monostable multivibrator MF then assumes its quasistabilcn switching state for the time T , in which the right transistor Q _t blocks and the left transistor Q * conducts. After the time T has elapsed, the monostable multivibrator MF flips back into its stable state. The negative "(^ -" /. "- Rüfkflankc of the pulse occurring at output A is ai: f the symmetrical differentiating input of the bistable flip-flop FF and flips it into the other stable state in which the left transistor Q _e leilct and the right transistor Q- is blocked.

In order that is the left output G ₁ of the flip flop FF '/.«-Signal (0 V), thereby the other gate C. ₁₃ R _t7, D is ₁₅ prepared in the input circuit of the monostable multivibrator A / F so that the next occurring at node E and guided onto the Torstiifc "quasi-stable /.«-Signal the monostable multivibrator Λ / Fwieder in their

The state from which it changes after the time T

falls back again.

The time t _m between the occurrence of the two measuring

pulses at output A of the monostable tumble sound MF represents the measuring time, which is shortened according to the temperature-related extension of the measuring distance. Another compensation for the temperature-related

Change in length of the measuring section can be achieved by mechanical means by, as has become known from the watch industry to avoid pendulum length changes, each of the rods S on which the measuring coils sit by a rod

system replaced, which means that there is no change in length in relation to the rod end.

1 sheet of drawings

709634m

■ yf * * "

Claims (1)

1 2 Measuring coils are attached to rods, thereby resulting in patent claims: indicates that the rods (S) are marked by an known rod system are replaced, which I. Means for determining the starting rod system in relation to the rod ends speed of a projectile with a measuring 5 does not experience any temperature-related change in length, encoder at the muzzle of a cannon barrel, containing two at a defined distance from each other arranged and from the storey well-worn measuring coils in which a pulse is generated when the projectile passes through, io
characterized in that a Device for compensating a temperature- The invention relates to a device for the conditional change in distance of the measuring coils (L _1. Tuning of the initial speed of a projectile- L ») is arranged. ses with a transducer at the mouth of a