US1624006A

US1624006A - Circuit arrangement for high-frequency sending stations

Info

Publication number: US1624006A
Application number: US619739A
Authority: US
Inventors: Osnos Mendel
Original assignee: DRAHTLOSE TELEGRAPHIE MBH
Current assignee: DRAHTLOSE TELEGRAPHIE MBH; Gesellschaft fur Drahtlose Telegraphie Mbh Hallesches
Priority date: 1922-02-18
Filing date: 1923-02-17
Publication date: 1927-04-12
Anticipated expiration: 1944-04-12

Description

til 12 1927. AP M. OSNOS CIRCUIT ARRANGEMENT FOR HIGH FREQUENCY SENDING STATIONS Filed Feb. 17, 1923 Swuemtoz MENDEL O5N05 Patented Apr. 12, 1927 v UNITED .oFFrc:E:..

TELE'GZRAPHIE M; GERMANY.

B21 H. HALLIESGHES; OF BERLIN, GERMANY, A

CORPORATION OF CIRCUIT ARRANGEMENT FOB,'HIGH-FZREQUENCY'SENDING STATIONSY Application filedTebruary 17,1923,1Serial No. 619,739, and in: Germany-February 18," 1922;

Thepresent invention is a further improvement on the arrangement described inmy application Serial No. 609,215 filed December-27, 1922.

In thedrawing+-- D Fin- 1 is a diagrammatic representation of a, circuit arrangement embodying; the invention described in said application, and

Figs. 2 to 5 inclusive are diagrammatic representations of circuit: arrangements of various forms embodyingthe presentinvention.

In 1 accordancewith said application, the generator is-connected in parallel with an element a so-called trap comprising a capacity (,l Inzdetermi-nin'g; the optimum properties of this trap, particularly its capacity; thefollowing; conditions must be observed. First, the operation-of. produc ing; oscillations of the'basic frequency must proceed in themost favorable manner, for example, the value' of the terminal potential of the: generator must-:not under any conditions vary materiallylfrom the idle running value; also as far: as possible the dynamo .urustisupply onlywatt'current; and also the operation: must: beas stable as possible etc. Second, for the purpose ofideveloping the strongest: possible; harmonic of the desiredefrequency iti is necessary that the oscillatingg-circuit as a whole, constitute either a-tuned :or slightly capacitive shortcircuit for: 'thedesired harmonic, disregardinn; ohmic losses but that:.it: constitute an essentially inductive reactance for the other harmonica .or if it' constitutes a capacitive reactance for-certain gother. harmonics, this mustbeso largethat no considerable oscillations of' undesired frequency will be Q'GllGl'fltGClay Third, as far as. possible the machine mustl be protected" from all harmonics operatinge waves as well as others.

The attainment" of-the second condition is first of all dependent on the value ofithat part of the station which:v comprises the above-mentioned capacity C the self-i11- duction ofdhogenerator andpossibly a further 'self induction connected in: parallel 5 with the-generator;- 1

These. three requirements are not always in: perfect i agreement r with each other. For

example if the saidcondenser comprisedlin the trap- -which, fast-above stated, forms part of the tuning apparatuswhich determines the" development of the necessary over waves-is dimensioned for the purpose of satisfyingithe second require1nent;.then it may happen'that the fulfillment of the other requirements will be i very difficultor impossible.v In: order toobviate this clifficulty in layingout-the sending-station,- in accordance with the present invention; a furthermargin of safety is introduced by providing-5a tuning; device which serves to determine the development of the'desi-red harmonic and which is-Tseparatefrom the trap (which is arranged in parallel with the generator; Preferably, this tuning element is-composed ofa capacity andan inductance provided in) p arallel with each otherand is arranged in series with an :iron corechoke coil. I

The -fo -i-'egoin will be" more fully er; plained by means of the circuit arrangement shownrin hlioyl; Inthis-figure, g is'the high frequency generator; G and the inductance of the generatoir is-t-he trap, L the iron core choke-coil, C awning condenser,- L a tuning inductance which. or a part of which'servesalso as a conpling; with the antennacircuit, A the -antenna and-L the extension coil...

The following should be: observed Y in determining the values of the separate: elements of-the station As faras the basic frequency is concerned, the current of this-frequency, as well as all others, passing through the condenser is leadingiwith respect-to its-terminal poten tial. Then the branch L, C L must bewso tuned that its primary; currentof basic frequency is .-laggin ','because only in thiscase can we satisfy the-first requirement for the basic frequency. If, forinstance; the-leading: component @of, the basic frequency. at the condenser C is exactly equal to the lagging component of the basic frequency in the loading branch L C L then' the-generator is freed from thewattless current and must supply only the minimum of current which a is a necessary for; covering the losses and theoperating wattless current out-- part. If, on the-other hand, the leadingwon:

denser current exceeds the lagging current components of the loading branch so that the generator must supply a leading current, no matter to how slight a degree, then the value of the terminal potential of the gen- .erator may be made at all times equal to the idle running potential.

It will be seen therefore, that, for the purpose of satisfying the first requirement the condenser must have such a value that its capacitive reactance is near the inductive reactance of the loading branch L C L for the basic frequency and preferably is equal thereto or slightly smaller.

If, on the other hand, it is desired to determine the value of the condenser G which would satisfy the second requirement then, as more exhaustive study of the problem has shown, this mustbe accomplished by tuning the closed circuit comprising the capacity C, and the self-induction L of the generator 9 connected in parallel with the capacity C, for a frequency which is lower than the desired operating frequency, but higher than the next lowest frequency existing in the station. However, if it is attempted to accomplish this, the capacity of the condenser C becomes so small that the third requirement cannot be fully satisfied. With respect to the harmonics which are lower than the operating frequency, the inductive reactance of the generator 9 will be smaller than the capacitive reactance of the condenser C so that it cannot serve satisfactorily as a trap, i. e. as a protection for the generator. Furthermore, the value obtained will be lower than is desirable for satisfying the first condition. 1

In order to obviate this difiiculty, in accordance with the present invention the condenser C is given so high a value that it will be satisfactory for the first and third requirements. However, with respect to the second requirement, the condenser C which now operates satisfactorily as a trap is no longer used as a means for developing the desired harmonic. The development of the desired operating harmonic is controlled by a tuning device which is separate from the trap and which may be connected in the loading branch in circuit with the iron core choke coil.

In Fig. 2 the tuning device in question is composed of a capacity C, and a self-induction L whereas the condenser G, is of sufficiently large dimensions to serve as a protection for the generator 9 against all harmonies.

The aggregate reactance of the tuning element (1,, L has a slightly inductive character for the basic frequency so that the loading branch may easily be made inductive for this frequency. On the other hand, the whole circuit which has a general multi wave character may now be tuned as a short circuit or as a low capacitive reactance for the desired harmonic.

The present improvement may be applied to all of the circuits described in my earlier application.

Thus, for instance, from the circuit shown in Fig. i of said application we may obtain the circuit shown in Fig. 3 of the accompanying drawings. In this figure also the said tuning element L C is provided in the loading branch in series with the iron core choke coil L The loading branch may in this case be so dimensioned as to have a capacitive character for the basic frequency when the coil L which, as shown, may he an iron core choke coil, is so dimensioned that, as far as the basic frequency is concerned, its lagging current covers entirely or partially the leading current of the condenser C and the loading branch or even exceeds it.

In a similar manner as disclosed in said application, under certain circumstances instead of using the tuning inductance L for coupling with the antenna, another inductance comprised in the oscillating circuit and in which the desired operating wave is strongly developed may be used, e. a coupling inductance L; as shown in Fig. 4.

In all of the circuits hereinbefore described, a potential is applied to the parallel capacity 0,, which is approximately equal to the generator potential. However, it may happen that the condensers are constructed for a much higher potential so that they cannot be fully utilized in the abovementioned circuits. In order to avoid this, the condenser C may be connected with the generator 9 either indirectly through the agency of transformers adapted to increase the potential or, preferably, a capacity C may be provided in the circuit through which the generator current passes. The condenser O and an inductance L, in the generator circuit may be so dimensioned that the potential of C will be sufficiently high for eflicient operation. An embodiment of this arrangement is shown in Fig. 5. The high potential at C, arises from the fact that, with respect to the basic wave of the generator, the circuit composed of L L 0,, and L C forms an inductive reactance, and the branch L 0 including the inductance of the generator forms a capacitive reactance. The same principle may be applied also to the other circuit arrangements.

Having described my invention, what I claim is:

1. A circuit arrangement for high frc quency sending stations comprising a generator, an iron core choke coil and an 111- ductance coil connected in series, a condenser connected in parallel with the gcnerator and in series with the iron core choke coil and the inductance coil so as to provide a loading branch circuit, an antenna coupled with said loading branch circuit and a tuning element separate from the condenser for promoting the development of harmonics of the desired frequency in the loading branch circuit, said condenser serving also as a protection for the generator against the harmonics.

2. A circuit arrangement for high frequency sending stations comprising a generator, an iron core choke coil and an Inductance coil connected in series, a condenser connected in parallel with the generator and in series with the iron core choke coil and the inductance coil so as to provide a loading branch circuit, an antenna. coupled with said loading branch circuit, and tuning means in the loading branch circuit for promoting the development of a harmonic of the desired frequency in such circuit, said means being composed of an inductance coil and a condenser connected in parallel with each other, the loading branch circuit being tuned as a whole substantially to the desired harmonic.

3. A circuit arrangement for high frequency sending stations comprising a generator, an iron core choke coil and an inductance coil connected in series, a condenser connected in parallel with the generator and in series with the iron core choke coil and the inductance coil so as to provide a loading branch circuit, a tuning element separate from the condenser for promoting the development of a harmonic of the desired frequency in the loading branch circuit, said element comprising an inductance coil and a condenser, and an antenna coupled with said last-mentioned coil.

A circuit arrangement for high frequency sending stat-ions comprising a gen erator, an iron core choke coil and an inductance coil connected in series, a trap connected in parallel with the generator and in series with the iron core choke coil and the inductance coil so as to provide a loading branch circuit, said trap having a capacitive reactance of suiiicient value to serve as a protection for the generator against all harmonics, and an antenna coupled with said loading branch circuit.

5. In combination, a source of alternating current, a circuit containing a frequency converter and coupled to said source, means connected in parallel to said circuit for protecting said source from the output frequency of said converter, said circuit having means for substantially resonating the output frequency of said converter, and means for utilizing said output frequency.

6. In combination, a source of alternating current, a first circuit containing a frequency converter and coupled to said source, a condenser connected in parallel to said circuit for protecting said source against the output frequency of the converter, means for causing said source to operate at substantially unity power factor, said means including a tuning circuit comprising a condenser and inductance. in parallel in said first circuit, said tuning circuit also causing the output frequency of said converter to be substantially resonated, and means for utilizing said output frequency.

MENDEL OSNOS,