DE1227167B - Electronically controllable delay line - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

PATENT LETTERING

Int. α .:

Number:

File number:

Registration date:

Display day:

Issue date:

H03h

German class: 21g-34

1227167
T14455IX d / 21g
November 27, 1957
October 20, 1966
May 3, 1967

The patent specification corresponds to the patent specification

The subject of the invention is an electrical delay line, in which the electrical that is decisive for the transit time of the transmitted signal Sizes are electronically controllable. Such runtime chains and their use to equalize Signals recorded on and taken from magnetic media are inherently safe the German Auslegeschrift 1014153 became known. In the known arrangements, control takes place by influencing the longitudinal inductances of the chain links by means of changeable pre-magnetization. The electronic control of such Structure has the advantage that it is in a static circuit, without mechanical intervention or to require forces, can be carried out with great speed, which is for the mentioned application examples is of great practical importance. Essential when using such electronic Time elements is often that the adaptation to the input and output resistance in the Control is retained. It is known (German Patent 866 672), longitudinal inductances and Train cross capacitances of a delay line in such a way that the characteristic impedance remains unchanged during control remains. It is also known to use semiconductor diodes for the electronic control of capacitances. It is also known (German Patent 819437) to make delay lines electronically to build controllable series inductances and electronically controllable transverse capacitances.

Fig. 1 shows a known example of a controllable Delay line. The runtime chain is made up of individual IT links, each of which consists of a Series inductance 1 and two capacitances 2 exist. The longitudinal inductances are with a ferromagnetic Core 3 is provided, onto which a second winding 4 is wound for direct current bias is. The input terminal 5 of the delay line is opposed to the input resistor 6 Ground and connected to the first filter element via a blocking capacitor 7. The output terminal 8 is due to the terminating resistor 9 of the filter chain, which is connected to the last via a blocking capacitor 10 Filter member is connected.

For the electronic control of the delay line, a control circuit 11 is provided which a control current as a function of the control voltages supplied to its input terminal 12 via the line 13 through the bias windings 4 and at the same time via the line 14 the capacitors 2 supplies a control voltage. The control circuit 11 is so electronic controllable delay line

Patented for:
Telefunken

Patentverwertungsgesellschaft mb H.,
Ulm / Danube, Elisabethenstr. 3

Named as inventor:
Paul-Gerhard Rothe,
Arno Müller, Ulm / Danube

tet that the control current through line 13 and the control voltage in line 14 as a function of the control voltage applied to terminal 12 are in such a ratio to each other, that the inductances 1 and the capacitances 2 change in the correct ratio to each other to the characteristic impedance of the delay line always increases to the value of the terminating resistors 6 and 9 hold while the running time changes at the same time.

With the known circuits described or mentioned so far, however, no controls can be carried out perform the inductances or capacitances that occur at frequencies that match the signal frequencies are comparable.

The invention is based on the object of creating a controllable delay line in which one Control of the running time with any frequencies is possible.

The invention is based on a delay line with electronically controllable line members Longitudinal inductances and electronically controllable transverse capacitances. The invention consists in a combination of the following partly known measures:

a) The LC line elements fed in push-pull by the useful signal are balanced to ground arranged, and the control currents are amplitude and phase correct to the series inductances fed;

b) the longitudinal inductances and transverse capacitances are in such a relationship to each other controlled in unison so that their wave resistance remains constant;

709 566/309

Claims (3)

3 4 c) between successive LC lines all parallel links with regard to the control voltage are firmly coupled Drössem with middle-switched diodes 52 is. In the event that at Punktsanzapfungen or resistance T-members of a larger number of filter elements of the Widerquer switched on, the taps of which stood 53 are not dimensioned sufficiently small Control voltage for the controllable Querkapa- 5 can, so that a frequency response due to Stromverteizitäten are fed. ment would occur between the resistor 53 and the parallel connected diodes 52, one must With a known, symmetrically structured predistortion of the applied to terminal 12 Line (USA.-Patent 2742 613) can be made led control voltage, which is through the a supply with the correct amplitude and phase io provided in the lattice circle of the tube 32 the control variable for the controllable inductances 57 happens. reach. A control of the capacities is Die F i g. 2 shows an embodiment for a but not thought there. Runtime chain made up of two IT links. The circuit For a more detailed explanation of the invention can be used in the same way for a larger number of in the following several exemplary embodiments on the basis of 15 filter elements and with minor modifications of the drawings. also for runtime chains from bridged T-links Fig. 1 shows a circuit in which between are carried out. successive LC line members fixedly coupled F i g. 3 shows another embodiment with pelte chokes with center taps in a symmetrically structured runtime chain in which are switched; 20 the symmetrical supply of the control voltage to FIG. 3 shows a circuit in which between the Zener diodes 52 via T-members 65 from ohmic successive LC line members resistors happens. These T-links 65, the jestands-T-links are switched on across; because between two filter elements and at the beginning Fig. 2 shows a circuit in which the influencing and end of the delay chain are switched on, influencing of the useful signal through the control signal there is a wave resistance that is equal to the by avoiding that the delay chain is a sym wave impedance of the other filter elements. To the metric line is built up. This requires the symmetrical supply of the useful signal from the essentially a doubling of the number of the tubes 39 are push-pull amplifier tubes 61, 62 before the delay chain self-forming switching elements. Seen, with the tube 61 from the anode of the signal is the delay chain from the 30 input tube 39 and the tube 62 from one Terminal 5 is fed via an amplifier tube 39, cathode resistance 66 of the tube 39 is controlled, the anode resistance of which the input resistance 6 also happens the decrease of the outputder Represents maturity chain. The output voltage signals from the delay chain by the counterfact the delay chain is connected to the grid of an amplifier-switched tubes 63 and 64. The tube 63 controls tube 40 supplied, at the cathode resistor 41 35 in the usual way the output tube 40 on the grid, the output terminal 8 is connected. while the tube 64 has an output side to the tube. The output signal of the tube 39 is the primary 40 parallel connected tube 40 'at the cathode winding of a transformer 54 supplied, which controls. The remaining switching elements of the execution secondary winding has a center tap, for example FIG. 5 are the same as in the accompanying case to the positive voltage source of e.g. 40 game of Fig. 4, and all- + 220V is connected. Each link of the term loan in connection with it indicated chain off consists of two controllable inductors 1, changes and additions to the circuit too which are provided in push-pull from the secondary winding of the here. Transformer 54 are fed. The circuit The cores 3 of the series inductances 1 of the delay control of the inductances via the winding delay line can each be provided with a gene 4 in FIG. 2 as well as in the following third winding, which is not shown again in the figures , since no further pre-changes that can be regulated at a resistor need to be made in it. magnetization scatter between the individual between each two filter elements, of which compensate in the longitudinal inductances, so that all on F i g. 2 only two are shown, a choke 56 50 can be set to the same operating point, which bridges the delay chain for identical and similar characteristics depending on the current and which has a central tap of which sits through all the biasing winding that - like the central tap of the 4 jointly flowing control current hung through the secondary winding of the transformer 54 - with the
positive voltage source is connected. This 55 Chokes 56 cause the voltage of the control claims:
frequency equal in amplitude and phase to all Diodes 52 arrives. It is essential that the 1st delay line with line members both throttle halves firmly coupled with each other from electronically controllable series inductances are. For coupling the output of the transit time 60 and electronically controllable cross capacities, chain to the output tube40 is a transformer characterized by the combination 55 provided, which in the same way as the trans- the following characteristics, some of which are known per se: formator54 is switched. The control voltage for the diode 52 is controlled by the control tube 32 at its a) The push-pull generated by the useful signal Anode resistance 53 is generated. Around a frequency 65 fed LC line links are balanced to The output of the control voltage supplied to the diodes 52 is arranged trisch, and the control currents To avoid it, it is necessary that the value of the longitudinal inductances are amplitude- Resistance 53 small compared to the impedance and supplied in phase; b) the longitudinal inductances and transverse capacitances are in such a ratio controlled in unison with each other so that their wave resistance remains constant; c) between successive LC line members are tightly coupled chokes with center taps or resistance T-links transversely switched on, whose taps provide the control voltage for the controllable Cross capacities are fed. 2. delay line according to claim 1, characterized in that as cross capacitances Semiconductor diodes with voltage-dependent capacitance in the blocking range (Zener diodes) and as Longitudinal inductances coils (1) with ferromagnetic 10 core (3 and a second winding (4) are used to bias the core. 3. delay line according to claim 2, characterized characterized in that the second windings (4) of the coils are in series with the control current are traversed and that each coil carries a third winding that is used for balancing one for each coil has an individually adjustable bias current flowing through it. Considered publications:
German patents No. 819437, 862 315,
672, 884519; German Auslegeschrift No. 1014153;
U.S. Patent No. 2,742,613. 1 sheet of drawings 609 707/342 10.66 © Bundesdruckerei Berlin