SU67364A1 - Tube generator - Google Patents

Description

The subject matter of the invention is a tube generator with external excitation, operating in the mode of amplifying modulated oscillations.

In the proposed generator, a known method for increasing the efficiency is used. and power by including in the grid circuit a tuned to the third harmonic circuit that serves to change the shape of the anode current pulse. A distinctive feature of the proposed generator is that, in order to increase the efficiency. and the power of the generator operating in the modulation mode of modulated oscillations by changing the amplitude and phase of the third harmonic voltage taken between the mean point and one of the ends of the specified circuit, between the other end of this circuit and the cathode of the lamp, a triode is connected to the grid from the divider connected to the grid voltage of the generator lamp.

The circuit of the proposed generator is shown in FIG. 1 of the attached drawing, FIG. 2 and 3 which illustrate the operation of the generator.

As shown in FIG. 1, in the grid circuit of the lamp L generator

An additional L, C, Ca, Cz circuit is tuned, tuned to the third harmonic (the LCi Cz circuit is tuned to resonance at the fundamental frequency). On this circuit, due to the passage through it of the anode current of lamp L1, a triple frequency voltage is created in the positive phase. The jli lamp, due to the presence of the grid, operates with a cut-off of 30-40 °, which allows the third harmonic to have a large value in its anode tsk. With modulation, the third harmonic of this lamp will first grow approximately in proportion to the excitation; later, due to the change in the shape of them: the pulse of la.mpa L (which should work with saturation, which is achieved by adjusting its heat), the growth of the third harmonic can be stopped and even made it negative. In addition, at the same time, the grid currents of the main lamp L, which create a voltage of opposite sign on the circuit, begin to increase strongly. Thus, fitting the lamp mode L and the equivalent resistance of the additional circuit can be achieved in such a way that the additional triple frequency voltage changes

with modulations, its amplitude according to the desired law, as shown in FIG. 2 by curve 2 (curve 1 in this figure represents the change in the amplitude of the fundamental frequency during modulation). With the indicated law of variation in the amplitude of the triple frequency, the shape of the pulses of the anode current changes with increasing modulation depth. The approximate nature of the change can be seen from the comparison of FIG. For and 36. In FIG. Behind. shows the shape of the anode current pulse for the case of the generator at the telephone point. Such a pulse shape is more advantageous in the sense of. K. E., Since for such a pulse the ratio of the first harmonic to the constant component can be obtained on the order of 1.8 (versus 1.57 in the case of a common cosine pulse with 0 90 °). .Thus, the increase in the coefficient - by 15% and the coefficient. ..

the use of anodic voltage for 10-15% allows you to have

. 2 Co

increase efficiency dn) at the telephone point by 25-30%.

Approximately the same increase in efficiency will also occur with modulation, since the circumstance that in the telegraph point the efficiency does not rise as much as sushi, naturally (for

a, saddle pulse -

 1.4 - 1.5), will not cause any significant reduction in the average efficiency, because the transmitter is in the maximum mode for a very insignificant part of the time with normal modulation.

For the case of the generator in the telegraph point, the shape of the anode current pulse is represented by figure 36.

An analysis of the generator mode with such a pulse shape shows that in this case it is possible to increase the oscillatory voltage at the anode (Ia by 10-15% compared to a conventional Generator, i.e., to bring the maximum value of the anodic voltage utilization ratio to 0.95 and more, without danger of causing sush; a natural decrease in the first harmonic of the pulse due to the onset of the overvoltage regime.

In addition, with such a pulse, it becomes possible to fully use the lamp by emission and, as a result, to increase the first harmonic of the anode current by 15–20% compared to a conventional circuit.

As is well known, in a conventional pattern, the lamp emission is used by no more than 70-75%, since obtaining a larger maximum pulse is associated with the need to have a very high value of the residual voltage at the anode.

fat

 -i-6), i.e. to have a coefficient of g max

The use of anodic voltage is of the order of 0.5-0.6, which is extremely disadvantageous.

Thus, the maximum power delivered by the lamp in the described mode can be increased by 30-35% against the usual mode with a cosine pulse.

An analysis of an anodic current pulse of a complex shape, formed as a result of the joint action of the exciting voltages of the main and triple frequency, shows that at the cut-off angle O-90 °, the amplitude of the first harmonic of the anode current is determined only by the exciting voltage of the fundamental frequency magnitudes (and phases) of additional voltage.

This circumstance is of paramount importance when the generator operates according to this principle, since, due to it, the law of variation of the additional voltage can be arbitrary with modulations, and this will not affect the linearity of the modulation characteristic.

Only from the point of view of the maximum increase in efficiency. and generator power needs to be done like this.

The 4to6bi etyt law possibly corresponded to curve 2 in FIG. 2

Subject invention

A lamp generator in which a circuit tuned to the third harmonic is switched on in the grid circuit to change the shape of the anode current pulse, characterized in that, in order to increase the efficiency and power generator operating in

the amplification mode of the modulated oscillations, by changing the amplitude and phase of the third-harmonic voltage taken between the midpoint and one of the ends of the specified circuit, between others: the end of this circuit and the cathode of the lamp include a triode, the grid of which is supplied with voltage from the divider connected to the grid generator voltage lamp.

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