DE406534C - Arrangement for generating electrical vibrations with a space charge grid tube - Google Patents

Description

(GS2SI7

It is known by a discharge tube Using a grid to generate electrical oscillations by creating an oscillating circle in a suitable phase takes energy from the anode circuit and a small part of it (Feedback) emits to the grid circle. A very corresponding circuit can be made at a space charge lattice tube. Here is the one closest to the cathode

ίο grid has a high positive DC voltage, while the second grating is used for feedback.

The present invention provides another circuit for generating vibrations that tubes on space charge grids or generally on tubes with a besoaderen positive electrode in the cathode compartment.

It is to be explored on a space charge lattice tube, i.e. H. at a Tube immediately attached to the cathode is a grid of high positive voltage, followed by it a grid of small, possibly negative voltage and then an anode of has a high positive voltage (Fig. 1).

It is common in electrodynamics, of

to speak of a "negative characteristic" and, if one is present, one Vibration generation under certain conditions that have the dimensions of a capacitance and resonance circuit containing self-induction should be considered possible.

A "negative characteristic" consists in the fact that a conductor of electricity at elevated Voltage lets a decreased current through and vice versa.

It should therefore be shown here to what extent a negative characteristic is present in the present invention. This is the circle (Fig. 1), which is formed by the cathode Ιζ, the battery E _z and the grid Q ₂ , with the segment KG ₂ in the tube in particular having the negative characteristic.

This negative characteristic, which has nothing to do with secondary cathode radiation, ionization or the like, can be seen from Fig. 2, which shows a set of characteristics. For all curves, the abscissas mean the imaginary variable grid voltage ^. The likewise variable voltage E ₂ of the space charge grating is used as a parameter, so that each cam is received, each with a certain space charge grid voltage E. ₂ The anode voltage Ea is unchanged for all points of all curves the same.

In Fig. 2 three types of curves are drawn, namely with / 4, with I ₂ and with I _g . They mean the rivers after

the anode I _A , the space charge grid I ₂ and the grid _{I g} . Each curve also shows an index (20, 3O ₃ 40, etc.) on the current designation; which specifies the parameter, ie the associated space charge grid voltage E ₂ in volts.

Although each of the curves I ₂₂₀ , I ₂ ^, I ₂ ^ etc. is inclined in the reverse direction than the curves / 4, they do not represent inherently negative characteristics, since the ordinates have their own currents, whereas the abscissas the Show tension of the control grid so that there is no self-dependence.

Rather, the negative characteristic can only be recognized when the association of I ₂ and E ₂ with a certain constant grid voltage E _g and a certain constant anode voltage (which is constant everywhere in Fig. 2) is determined. This is done, for example, for the point Eg = - 6VoIt (see dotted line P) and can be drawn especially in Fig. 3. You can see the falling characteristic (or negative characteristic) between E ₂ = 20 volts and E ₂ = 100 volts. The cause of this negative characteristic is as follows:

In the case of the space charge lattice tube there is a complicated relationship between Ea, E ₂ , Ia, Iz, since the current is always distributed between the anode and the space charge lattice, so that both influences on the one | and insist on the other, but which is, j as the sum of both currents approximately constant \, thereby again affecting each other. Thus, an increase in the space charge grid voltage is initially a direct cause of an increase in the space charge grid current and thereby a decrease in the anode current. In the second row is an increase in the space charge lattice voltage. but, the cause of the increase in the mean potential in the grid surface and thereby at the same time a cause of the increase in the anode current, thus reducing the space charge grid. The second influence tends to predominate, especially when working with voltages above j saturation. This can be expressed in such a way that the space charge grid voltage also has a penetration through the grid, which is the actual cause of the negative characteristic. I The negative characteristic can initially be used in such a way that with it in series ι an oscillation circuit, z. B. in flywheel circuit, is placed (Fig. 4), which is then excited by the tube under conditions to be discussed in more detail. According to the invention, this property is now intended for circuits for generating vibrations:

supply something to be exploited more generally by one is produced the whole process of self-sustaining AC voltage _v through an organ sufficient voltage drop in the space charge grid line.

This can be expressed as follows if Ia is an anode alternating current, i _{2 is} the space charge grid alternating current, € a is the anode alternating voltage, e _{g is} the grid _{alternating voltage, e z is} the space charge grid alternating voltage, α is the penetration of the anode voltage through the grid surface, ζ the penetration of the space charge grid voltage through the grid surface:

ΰ - f (% ■ + «· e _A -f ζ e _K ), (1)

where / should mean a simple function. The resistor R (e.g. formed by an oscillating circle in the flywheel switch) is now in the anode lead

processing, so that R = - ^ n), furthermore in the

Space charge lattice line is the resistance Z. Then from (1)

(2)

Here is the dependence of the current on the voltages, i.e. the function / as linearly assumed what z. B. is fully applicable for small amplitudes, therefore is also sufficient to explain the process of the onset of the vibrations. Let it be set:

(3)

iA = Q- { ^e e ~ ^aRi A—

(4)

This results in:

Since, as said above, the anode current and space charge grid current are almost exactly opposite each other since the total current is constant (the saturation current), one can set:

, ■ —__; fei

so that

i _A = - ^ (e _g -

(6)

The idea of the invention can now be used in a number of different circuits to pressurized. In the relevant Figs. 4 to 8, which such circuits show is warped to an alternating grid voltage by attaching the grid directly to the Cathode is placed. It can also be completely

dig stay isolated. Therefore, the AC grid voltage will be omitted in equation (6) or will

In Fig. 5 an oscillating circle is used in the anode circle, for which R - - = ^

is, in the space charge grid line a pure resistance Z. The condition for that the process is self-sustaining, according to (6):

i _A - p '( -

ζΖϊ _Λ )

and from this:

■ = Q + nR

(8th)

(9)

In Fig. 6, R is a pure resistance, whereas Z =

= 7 = r-

C ₁ K ₁

Circle.

Then the condition for self-preservation is:

and from this:

L ₁

ζ> ρ = Q - \ - 0.R- (11)

C ₁ R ₁

In Fig. 7 both resistances are oscillating circles and a simple derivative shows that they should be coordinated with one another as precisely as possible, but that mutual coupling is superfluous.

Then the conditional equation results:

C ₁ R ₁

(12)

This latter circuit has the advantage that the usable energy is increased, since both circles supply energy, while in Fig. 5 and 6 a part of the energy in the pure resistance was R or Z is destroyed.

Furthermore, the resistor in the anode lead can be omitted (Fig. 4), for which purpose the condition results:

(13)

The impedance in the space charge grid line, which is the basis of the invention, on the other hand, cannot be omitted, because the result would be:

an oscillatory which cannot be realized, since Q, · a, L, C, R are all absolutely positive.

The two circles in Fig. 7 can also, without this being necessary, for the sake of simplicity be combined, as shown in Fig. 8.

One can also use the described excitation principle only partially by one does not completely fulfill the above conditional equations, but a small one Applying addition of the known grating feedback by z. B. on one in the true Coil lying on the grid line induced by one of the circles.

Claims (5)

Patent Claims: 1. Arrangement for generating electrical oscillations with a space charge lattice tube or a tube which has a strongly positive electrode near the cathode, characterized in that for Excitation the negative characteristic, which is caused by the influence of the positive electrode on the mean potential in the Area of a true grid and thereby on the anode current is used. 2. Arrangement according to claim 1, da- go characterized in that in the lead to the positive electrode a vibratory Circle is arranged. 3. Arrangement according to claim 1, characterized in that in the supply line an ohmic resistor is arranged to the positive electrode, with vibratory elements in the anode circuit are switched on and the energy is drawn from the anode circuit. 4. Arrangement according to claim 1 or the following, characterized in that the Energy extraction either from the space charge lattice circle alone or from the Anode circle or at the same time from both, either by two separate ones Organs or by a common. 5. A circuit according to claim r, characterized in that the true grid is immediately connected to the cathode. 1 sheet of drawings.