US1596198A - System for generating oscillations - Google Patents

Description

Aug, 17 1926.

S. LOEWE SYSTEM FOR GENERATING OSCILLATIONS Filed March 19.

Patent eale 18. 17.1926. i'

I UNITED. STATES smeuunn LOEWE, or BERLIN,

1,596,198 PATENT OFFICE.

GERMANY, ASSIGNOR T WESTERN ELECTRIC com- PANY, mooaronn'rnn, on NEW YORK, N. Y.,- A CORPORATION. or- NEW YORK.

' sYs'rnm non GENERATING OSGILLATIONS.

Application filed March 19, 1921, Serial '30. 453,841, and in Germany April 19, 1918, (GRANTED UNDER THE PROVISIONS 01 THE ACT OF MAIRCE 3, 1921, 41 STAT. 13., 1313.)

This invention relates to oscillation-generators, using electron discharge tubes hav-- ing a plurality of electrodes. An object L of the invention is to provide .an oscilla- 5 tion generator, oscillating directly into an antenna or other load circuit of variable impedance so arranged that variations of the antenna or load impedance have a very small effect on the frequency of oscillation. In other words the oscillation generator is s0 arranged that the frequency of the output current is substantially independent of said output current or variations in the impedance of the output circuit. This is accomplished by providing an anode, which constitutes the anode for an auxiliary oscil lating circuit, but also functions as a grid with respect to a principal anode connected to the main oscillation circuit.

The invention also comprises novel electrode arrangements adapted to be utilized in tubes for carrying out the invention. From one aspect, the system herein described, may be regarded as an oscillation generator connected to an amplifier which amplifies the generated oscillations, the oscillation generator and the amplifier being combined in one vacuum tube and having a common cathode. The output circuit of the oscillation generator may be treated as the input circuit of the amplifier.

The generation of undamped electrical oscillations by vacuum tubes becomes more diflicult in proportion as the antenna is more strongly damped. At'the same time the total efliciency of the oscillation generation is greatly decreased. The present invention deals with an apparatus which will avoid this condition. The cause of this condition was recognized to be the comparatively ineflicient operation of the grid of the vacuum tube in the common arrangement. The basic idea of the invention is the use of a means for increasing the grid effect beyond that caused by the feed back.

\ Fig. 1 shows a space discharge oscillator embodying the invention. Fig. 2 represents a modified arrangement of the electrodes of I the space discharge tube. Fig.3 shows an other arrangement of the space discharge tube electrodes. Fig. 4 shows a different form of oscillation generating. system embodying the invention.

In Fig. 1, a vacuum tube or space ourby the coil 9. The grid 3 is excited by the auxiliary anode or output circuit 10 which may include the resonant circuit 11 and thereby induce a potential upon the grid by means of the input circuit including'the coil 12. A part of the chief anode battery may serve with advantage as the battery of the auxiliary anode circuit, but the heating battery or a special source of voltage may also be used for'this purpose. If the anode source Is not constant, but an alternating current machine, a transformer may be used, so that the voltage of the auxiliary anode circuit can even be chosen larger than that of the chief anode circuit. 2

The method of operation is as follows:

Oscillations of the frequency determined by the resonant frequency of the tuned cir-' cult 11 are generated in the auxiliary anode circuit 10 in the usual manner by means of the anode battery 6 and the feed back 12.

Qn account of the arrangement of the osc llation generator with respect to the mam output circuit, the tuning of circuit 11 18 independent of variations in the impedance of the main output circuit. The grid variations thus produced naturally act also on the real anode circuit consisting of the anode 4, coil 9, and source of voltage 6; a high frequency current flows in this circuit 90 and has the same period as that of the auxiliary anode circuit. The antenna is now coupled with the main anode circuit and set in resonance with the frequency generated in the auxiliary anode circuit. It is vital 95 that the auxiliary anode system andv the grid coil should be made as free from damping as possible, since it is important be cause of the dissipation to generate the highest possible grid variations with the least 100 possible energy.

The auxiliary anode system can always be chosen with a view to the greatest possible grid effect, thatis with circuit 11 as free as possible from damping and transforma- 105 .tion to high grid potential- Hence great It is advisable to arrange the auxiliary anode inside the main anode as shown 1n 'Fig. 2. The auxiliary-anode can itself be constructed as a id and can act as such for the main anod d. (cf. Fig. 3).

If the present method is combined with an ordinary circuit for the generation of oscillations, pure undamped oscillations W111 be obtained when the main and auxiliary anode circuit are in resonance with each other, and a beat transmitter will be obtained when the two circuits are slightly out of resonance.

The application of this is shown in Fig. 4.

A feed back with the antenna is formed by means of coil 13. If the antenna is slightly out of resonance with respect to circuit 11, beats are obtained. I

\Vhat is claimed is:

1. Means for generating oscillations including a space current device having electrodes,.an output circuit having a direct current conductive connection to electrodes of said device, and means including said device for transmitting oscillations to said output circuit from said generating means at a frequency substantially independent of current in said output circuit.

2. Means for generating oscillations including a space current device having electrodes, an output circuit having a direct current conductive connection to electrodes of said device, and means including said device, responsive to oscillations in said enerating means, for transmitting said oscillations to said output circuit at a frequency substantially independent of current in said output circuit.

3. Means for generating oscillations in cluding a space current device having a plurality of electrodes, and output circuit associated with said device, and means including a direct current conductive connection between said circuit and one of said electrodes for transmitting oscillations to said output circuit at a frequency substantially independent of current in said output circuit.

4. Means. for generating oscillations in cluding a space current device having a plurality of electrodes, 3. variable load circuit directly connected to said device, and means including one of said electrodes for trans-,

mitting oscillations to said output circuit at a frequency substantially independent of variations in said load circuit.

5. Means for generating oscillations including a space current device having a plu rality of electrodes, a load circuit containing a variable impedance element directly connected to said device. and means including one of said electrodes for transmitting oscillations to said load circuit at a frequency substantially independent of variations in said impedance element.

6. Means for generating voscillations ineluding a space current device having a plurality of electrodes, a load circuit includingspace discharge tube including a plurality of anodes and a common cathode, means for producing continuous discharges in a pinrality of space paths between said cathode and said anodes; a control electrode adapted to control the discharges in a plurality of said paths, associated reactive networks for producing self sustained oscillations in one space ath, and a work circuit connected to the ot er space path.

8. In an oscillation generator, a space discharge tube including a cathode, control electrode and a plurality of anodes, means for causing said control electrode to vary the impedance of the space paths between said cathode and both of said anodes, and an output circuit having a direct current conductive connection to an anode, whereby variations of impedance of said circuit are prevented from affecting the frequency of oscillations.

9. In an oscillation generator, a space discharge tube including a cathode, control electrode and a plurality of anodes, an oscillatory circuit connected to said cathode and one anode, a load circuit connected to said cathode and a second anode, said control electrode being adapted to independently control the spacevdischarge between said cathode and said first mentioned anode, said first mentioned anode and said control electrode being adapted to jointly control the discharge to said second anode.

10. A space current device having an anode, cathode, and a control element, an

input circuit connected to said control element, and a tuned output circuit connecting said anode to said cathode to transmit current in response to oscillations in said input circuit, said input and output circuits being coupled together, a second anode for said cathode, and a variable output circuit connecting said cathode to said second anode to transmit current in response to oscillations in said first mentioned output circuit, the tuning of said first mentioned output cir cuit, the tuning of said first mentioned output circuit being substantially independent of variations in said second output circuit.

11. A space current device having an anode, a cathode, and a control element, an input circuit connected to said control element, and an output circuit connecting said anode to said cathode to transmit current in response to oscillations in said inputpircuit,

said input and output circuits being coupled together, a second anode for said cathode, said second anode comprising portions located on opposite sides of said first anode, and a second output circuit connecting said cathode to said second anode to transmit current in response to oscillations in said first mentioned output circuit.

12. In combination, a space current device, a load circuit including a damped antenna having direct current conductive connection to said device, and means including said device for generating oscillations unafi'ected by the damping of said antenna.

13. A circu it comprlsing a space discharge device, a cathode therein, two cold anodes therein, an external circuit connected to said cathode and one of said anodes, a load circuit coupled to said external circuit, another external circuit connected to said cathode and the other of said anodes, an

in ut circuitand a feed-back coupling from sald last named external circuit to said input circuit,,said first named external circuit being free of material external electromagnetic or electrostatic coupling to said input circuit.

14. A circuit comprising a space' discharge device having a cathode and two anodes, an input circuit, one of said anodes being included in an external circuit, means in said circuit to transfer waves to a load circuit, and the other of said anodes being included in another external circuit and means in said last named circuit functioning essentially to transfer waves to an input circuit of said device.

In witness whereof, I hereunto subscribe my name this ninth day of February, A. D., 1921. a

DR. SIEGMUND LOEWE.

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