DE1112107B - Method and circuit arrangement for delaying pulse trains - Google Patents

Description

Method and circuit arrangement for delaying pulse trains The invention relates to a method for delaying electrical pulse trains, in particular by means of magnetostrictive delay devices.

There are devices of this type known in which, for example an input energy converter is used when electrical impulses arrive To build up tensile or compressive stress waves in a deceleration element, the Delay element in the form of a rod, wire, strip or tube made of magnetostrictive Material is formed, while an output energy converter is provided to then to respond to such pressure or tension waves and into electrical energy reshape when they move a certain distance through the delay element have moved through. By adjusting the length of the delay element between the two energy converters can set the time delay to a predetermined value can be set. The energy converters used in such facilities are usually inductively coupled to the delay element.

The mode of operation of such a device is roughly as follows: By the magnetic induction change, which is caused by a signal in the input energy converter is caused, the dimensions of the delay element due to the magnetostrictive properties of the delay element in the area of the vibration generator changed, and an acoustic pressure wave is generated in the element, which in the element wanders away. The pressure wave changes the dimensions of the delay element im Area of the output converter and thereby induces an output signal in it Converter through the magnetostrictive reversing effect.

Such delay devices are already known, and they can be designed to be satisfactorily pulsed with input work, each of which has a duration in the range of a microsecond or more to have. However, in various fields of use, it is desirable that such Devices are operated with input pulses, each of which has a duration less than 1 microsecond, for example 112 microsecond, and a pulse repetition frequency in the 1 megahertz range. If this is the case with such known delay devices attempts are made, however, difficulties arise.

For example, if the wave finds the output transducer wandered through, a change in the permeability of the magnetostrictive material takes place inside the coil, causing an induced voltage in this coil will. When the wave arrives, there is a voltage change in one, for example negative direction takes place, and when it emerges there is a voltage change in the other direction. Similarly, through the trailing edge of the shaft induces a voltage curve, which leads to voltage changes in the output coil Result, namely a positive impulse upon arrival and a negative impulse when exiting.

If the pulse transmitted to the input transducer exceeds a predetermined Duration relative to the length of the input and output transducers and the property and to the dimensions of the delay element, the two add upwards directional change or peaks of the voltage waveform at the output converter, what a resulting waveform gives a small, or narrow, downward has directed voltage change, which is a wider, upward voltage change and another small, downward voltage change follow. This This phenomenon is known to those skilled in the art of acoustic delay lines known. Here, the time occurrence duration of the ideal output waveform is approximate equal to three times the duration of the impulse sent to the input transducer is transmitted.

The duration of the output waveform is the length of the voltage wave that this waveform creates. Occurs inside the delay element due to various reasons, a broadening or dispersion, and this is the longer the delay, the greater. If the input pulses with sufficient Successive speeds, it has proven impossible to control the output waveforms dissolve sufficiently for the facility to function reliably to be able to achieve.

In order to cope with the aforementioned difficulties, it is proposed have been made to operate two half-length delay elements connected in series, the first of these elements being pulse conversion control circuits and an amplifier follow to apply the second of these elements. However, it turned out that the dispersion value in otherwise excellent retardation element materials a law that reproduces the dispersion relative to the distance traveled follows, which is approximately exponential, so that in a delay element half the length the dispersion is only slightly smaller than in a delay element full length, and the amplification and reshaping of the impulses is at the end of the element half-length almost as difficult as at the end of a full-length element.

The purpose of the invention is to provide an improved electromechanical Delay device for high pulse repetition frequencies at which the The aforementioned difficulties are significantly reduced and the delays are longer than previously can be achieved.

The method according to the invention for delaying pulse trains with short pulse pauses and high repetition frequency with several delay devices, especially magnetostrictive delay lines, is characterized by that by coincidence circuits with added synchronous pulse trains of 1 / n the applied pulse repetition frequency the first pulse of the pulse chain to the first Delay device, the second pulse to the second delay device connected in parallel and the n-th pulse arrives at the n-th delay device connected in parallel and those with 1 / n of the pulse repetition frequency the individual delay devices Time-staggered pulse chains at separate output energy converters removed and through a combination circuit analogous to the pulse chain separation, z. B. by means of "AND" circuits with added synchronous pulse trains of 1 / n the original pulse repetition frequency, to be reassembled.

Thus a pulse train to be delayed becomes a number of pulse trains lower pulse frequency, whose pulses are temporally shifted over separate Delay devices are running. Different sections can be customized delayed, and selected areas of these delayed sections will be delayed combined or combined and fed to the common output control circuit or transmitted. For example, the arrangement can be made so that then if a negatively directed area of the one delayed section, which is reproduced by an output transducer, with a positive Directed area of a section passed through another output transducer is reproduced, should coincide in time, only the positively directed area is played, or vice versa.

In a preferably used embodiment of the invention the delay elements each have the shape of a wire, the magnetostrictive one Has properties while the input and output converters are in the form of coils are formed, which are coupled inductively to the wires.

The coincidence circles are each between the input control circuit and the input transducers switched and arranged to be in sequence be opened and closed by impulses that are transmitted to them.

The gate pulses are in phase with the transmitted pulses brought.

Any conventional device can be used as a combining circuit for the supply of selected areas of the signals which are in the output converters occur after the shared output control circuit. So can for example, biased diodes or rectifiers connected to the output converters for passing signals that are above the bias level lie after the output control circuit. Pre-stressed conversion devices, for example transistors or electron discharge tubes can be used. At a In the exemplary embodiment, the combination circuit has a plurality of electron discharge tubes on, whose cathodes are connected to one another and by means of a common load resistor are connected to a negative power source, while their anodes are connected to a positive Power source are connected, the control grid of the pipes by positive-going Output signals are driven by the mentioned delay elements can be obtained by means of the respective output converters and amplifiers, wherein the mentioned grids are biased to determine the signal level which is exceeded must be generated before output signals are generated.

In another embodiment of the invention, the signals occurring in the output converters via separate coincidence circles communicated to the common output control circuit. The circles of coincidence exist with "AND" gates, each of which requires two output voltages to generate one To generate output voltage.

An input voltage is that which is generated by the assigned to the gate Output transducer is caused while the other is caused by an occurrence pulse is formed. The performance impulses that are transmitted to the various goals have different performance instantaneous values, which are chosen so that predetermined ranges of voltages are selected by the output transducers.

The invention is now to be reproduced by way of example Drawing will be explained in more detail, namely Fig. 1 shows in logical diagram form a delay device, Fig. 2 is a circuit arrangement diagram a combining control circuit for use in the delay device according to Fig. 1, Fig. 3 in logic diagram form a further delay device, while Fig. 4 is an explanatory diagram.

1 shows a delay device which consists of two delay elements 10 and 11 made of wire which has magnetostrictive properties, the wires being equipped with input coils 13, 14 and output coils 15 and 16, respectively. The input circuit 17 is provided with an amplifier 18 , the output of which is connected to two "AND" gates 19 and 20. The “AND” gate 19 is supplied with gate pulses from a generator 21 , while the “AND” gate 20 is supplied with gate pulses from a generator 22. The input signals appearing in the input circuit 17 have a pulse shape, and the arrangement is such that the pulses caused by the generators 21 and 22 run synchronously with the input pulses in the input circuit 17, but occur halfway through the repetition frequency of the input pulses, and that the through the two generators generated pulses are interlinked in such a way that the gates 19 and 20 are opened alternately. The gate 19 is connected to an amplifier 23 and from there to the input coil 13 of the delay element 10 . In a similar way, the gate 20 is connected to the input coil 14 of the delay element 11 by means of an amplifier 24 . The output coils 15 and 16 are each connected via amplifiers 25 and 26 to a combination circuit 27 and from there via a pulse stretching and conversion control circuit 28 to a common output circuit 29. The combining circuit 27 is intended to pass through all the positively directed signals which exceed a predetermined reference signal value or level after the control circuit 28 and block all signals below the aforementioned predetermined signal level. An exemplary embodiment of a suitable combination circuit is described in more detail below with reference to FIG. 2.

During operation, the input pulses occurring in output circuit 17 are amplified in amplifier 18 and then passed through to "AND" gates 19 and 20 at the same time. The gates 19 and 20 are switched alternately by the pulses, which. generated by the generators 21 and 22 and; which are in phase with the input pulses in such a way that a gate pulse is passed through either to gate 19 or to gate 20 during each input pulse period. The "AND" gates 19 and 20 each produce an output pulse when an input pulse is transmitted to them at the same time as a gate pulse, with the result that input pulses are alternately switched or switched to the amplifiers 23 and 24 through the "AND" gates. be transmitted. The amplifiers 23 and 24 drive the coils 13 and 14, respectively, to thereby generate pressure waves in the lines 10 and 11 in accordance with alternate input pulses, respectively.

After they have traversed the delay elements 10 and 11, these pressure waves produce output pulses in the coils 15 and 16. The output pulses are amplified in the amplifiers 25 and 26 and transmitted to the combining means 27. The shaping control circuit 28 evaluates the signals from 28.

It is evident that when two delay lines are used, the pulse repetition frequency in each of the delay elements 10 and 11 is half that of the input pulses and, for this reason, a considerably larger distortion due to dispersion can take place in each delay line before there is an overlap in each delay line. Therefore, lines 10 and 11 can be considerable in length and delays in excess of 900 microseconds can be achieved with input pulses 0.5 microseconds in length.

Reference is now made to FIG. 2, in which a circuit arrangement an embodiment for the amplifiers 25, 26 and a combination circuit 27 according to Fig. 1 is illustrated.

In FIG. 2, 25 is the amplifier of two Pentodenrohren 30 and 31, and it corresponds to the amplifier 25 of FIG. 1. The output transducer 15 of the delay element 10 is connected between the control grid and the cathode of Pentodenrohres 30 which an anode load resistor 32 owns. The anode of the tube 30 is coupled to the control grid of the tube 31 via a capacitor 33, and the anode of the tube 31 is provided with an anode load resistor 34 . For completeness, the other conventional elements such as grid leakage points, cathode bias resistors, etc. are plotted on the drawing and their resistance and capacitance values are also included.

The amplifier 26 has two further pentode tubes 35 and 36 and corresponds to amplifier 26 of FIG. 1. It is identical to amplifier 25.

Signals occurring at the anode of the tube 31 are transmitted to the control grid of a triode tube 39 via a capacitor 37 and a resistor 38, which are connected in series. In a similar way, signals occurring at the anode of the tube 36 are transmitted to the control grid of a triode tube 42 via a capacitor 40 and a resistor 41, which are connected in series. The two triodes 39 and 42 can be in the same envelope, as shown.

A common cathode load resistor 43 is provided for the two triodes, and that end of this resistor which is furthest from the cathodes is connected to a terminal 44 which is supplied by a voltage supply source (not shown) at a potential of -50 Volts is held relative to earth. Two resistors 45 and 46 are each connected between the anodes of the two triodes and the positive terminal HT + of an anode power supply source (not shown), the negative terminal of which is connected to earth.

Two potentiometers 47 and 48 are provided for the purpose of negative biasing of the control grids of the two triodes. The resistance element of each potentiometer is connected between the negative terminal 44 and ground, while the switching arm of the potentiometer 47 is connected to the control grid of the triode 39 via a resistor 49 and the resistor 38. The switching arm of the potentiometer 48 is connected to the control grid of the triode 42 via resistor 50 and resistor 41. Decoupling capacitors 51 and 52 are each connected between the switching arms of the two potentiometers 47 and 48 and ground.

During operation, the biases are on the control grids and cathodes of the two triodes 39 and 42 chosen so that areas of signals that are negative with respect to the average, which corresponds to the cathode level, are not can be reproduced via the common cathode load resistor 43. Positive However, portions of such signals are reproduced and thus, if a negative range of a signal from amplifier 25 with a positive range of a signal from amplifier 26 should match, the former area does not while the latter is being played back.

The cathodes of the triodes are connected to an output terminal 53.

The exemplary embodiment according to FIG. 3 will now be described. In 1 and 3, the same elements have been given the same reference numerals.

The input circuit in FIG. 3 is connected to the two “AND” gates 19 and 20 via an “OR” gate 54, and the mode of operation of the elements 19, 20, 21, 22, 23, 24, 13, 14, 10 , 11, 15, 16, 25, 26 and 28 has already been described with reference to FIG. A pulse generator 28 ′ is connected to the control circuit 28.

Instead of the combination circuit 27 of FIG. 1, which is referred to with reference on Fig. 2 has been described in more detail, the combining circuit which is within the dashed line 27 of FIG. 3 is drawn, is used.

This combination circuit initially consists of two pulse shapers 55 and 56, which are provided to receive them from amplifiers 25 and 26, respectively to stretch and reshape transmitted impulses.

The outputs of the pulse shaper 55 and 56 are then each after transmitted to both "AND" gates 57 and 58.

The pulses from the pulse generators 59 and 60 are transmitted to the "AND" gates 57 and 58 , and an output voltage always occurs in the output control circuits of the "AND" gates 57 and 58 when there is agreement or coincidence between the There are voltages which are transmitted to your two input control circuits.

The pulses generated by pulse generators 59 and 60 are as the pulses generated by units 21 and 22 have a frequency that is half is the input pulse frequency and they are chained together. you will be used for the "AND" gates 57 and 58 after the expansion and deformation control circuit 28 transmitted impulses, sharply pronounced by gate switching of the last-mentioned impulses To give leading edges. The trailing edges of these pulses are as described below is kept sharply defined by the pulses which are in the pulse generator 28 'can be generated.

The output voltages occurring in the “AND” gates 57 and 58 are transmitted to the pulse stretching and reshaping control circuit 28 and from there to the output wire 29 and via a return connection 61 to the “OR” gate 54, thereby re-circulating -bringing the signal can be effected.

Typical waveforms of the signals transmitted from input 17 are illustrated in Figure 4 (f). The pulses 62 are regularly spaced from each other and may or may not be present, as indicated by the label "OR NOT" is indicated in the drawing.

Figures 4 (d) and 4 (e) each illustrate the gate or clock pulses, which respectively from the pulse generators 21 and 22 after the "AND" gates 19 and 20 be transmitted. The time scale for all of the waveforms shown in Figure 4 is illustrated in Fig. 4 (g), and it can be seen that the negative-facing Clock pulses 63 and 64 match with alternating input pulses 62. Consequently pulses are alternately transmitted to the two input transducers 23 and 24 or transmitted.

The distorted pulses appearing in the output transducer will reshaped and stretched by the pulse shapers 55 and 56. The reshaping can expediently z. B. caused by the fact that only the tips of the positively directed areas of the signals can be selected. Stretching can be done in the usual way by means of a capacitor done, which is charged via a rectifier control circuit and via a resistor is discharged. In this embodiment, the arrangement can be made so that there is a stretch or delay of about 1.6 microseconds.

Sharp leading edges are then created using the "AND" gates 57 and 58, with these gates coming from the pulse generators 59 and 60 transmitted impulses each have the waveforms and phases indicated at 65 and 66 are indicated in Figures 4 (a) and 4 (b).

The pulse stretching and transforming control circuit 28 may be any conventional one Have embodiment. Thus, in the case of the pulse formers 55 and 56, the pulses can thereby are stretched by charging a capacitor while the trailing edges are through Pulses are determined, which open a rectifier and thereby the capacitor unload. Such circuit arrangements are known, and the expansion and Conversion control circuit 28 from generator 28 'for the purpose of determining the trailing edges of the pulses transmitted pulses can be designed as shown at 67 in FIG Fig. 4 (c) is indicated, whereby the waveform of Fig. 4 (f) are reproduced can.

The embodiment illustrated in FIG. 3 can be carried out with the aid of the return connection 61 for storing a completed pulse train via any Length of time in the form of a pattern of pulses 62 can be used. (This represents a well-known way of storing information. The existing For example, impulses are binary "ones" and the non-existent impulses are binary »Zeros« again.) If the information symbol is to be changed, the existing Pulse chain by means of a gate or a switching mechanism (not shown), which are switched into the return connection 61, deleted and new pulses at the input terminal 17 are fed.

It is apparent that although embodiments are described have been, at which Magnetostrictive Delays are used, in addition, other delay devices, for example Columns of mercury, can be used. Other than the above can also be used described switching and combining means or devices are used.

Claims (3)

PATENT CLAIMS: 1. Method for delaying pulse trains with short pulse pauses and high repetition frequency with several delay devices, in particular magnetostrictive delay lines, characterized in that the first pulse of the Pulse chain is sent to the first delay device (10), the second pulse to the second delay device (11) connected in parallel and the n-th pulse to the n-th delay device connected in parallel and which stagger the individual delay devices with 1 / n of the pulse repetition frequency passing pulse chains removed from separate output energy converters (15, 16) and through a combination circuit (27) analogous to the pulse chain separation, z. B. can be reassembled by means of "AND" circuits (57, 58) with added synchronous pulse chains of 1 / n of the original pulse repetition frequency. 2. Circuit arrangement for carrying out the method according to claim 1, characterized in that the combination circuit (27) is provided by prestressed, Conversion devices (55, 56) assigned to each output converter have a specific one Combines pulse chains exceeding reference level. 3. Circuit arrangement for carrying out the method according to claim 1, characterized in that a return connection (61) for the transmission of pulse trains from the output (29) via an "OR" gate (54) to the input is provided, which the delayed pulse trains again circulates. References considered: U.S. Patent No. 2,812,448.