SU39844A1 - Generator - Google Patents

Description

In some issues of laboratory practice in the field of radiotelegraph measurements and acoustics, it is necessary to have a source of high-frequency oscillations with a frequency varying periodically over wide limits. Since the frequency of the local oscillator depends on its mode of operation, it is possible, periodically to make certain changes in the model of its operation, to change its frequency.

As is well known, the reverse action, which is a self-excitable oscillator, changes the frequency of this generator in the event that the phase of this action differs from the phase of the main pulse. The maximum change in frequency is obtained by shifting by 90 °. The magnitude of the phase-shifted current, or the most phase shift, is controlled by the initial CONDITIONS of operating the reverse action, the grid of which is supplied with alternating voltage from the oscillatory circuit of the generator. The initial conditions of the lamp operation are most often determined by changes in the grid bias caused by an auxiliary source of a periodic nature, for example, a relaxation generator.

The proposed device p | is a self-excited generator

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with net capacitor and leakage; the magnitude of the latter, as well as the connection between the anodic and grid circuits, is chosen so that intermittent oscillations with a predetermined relaxation period occur in the generator.

In drawing 1 - generator lamp, 2-reverse lamp, impact. In the absence of a reverse action, the oscillation period is determined by the parameters of the oscillating circuit with self-induction-3 and capacitance 4, since the alternating voltage on the grid is determined only by e. D. s, induced in the grid coil from the anode circuit. With sufficiently strong coupling and corresponding resistance, the oscillations cause the capacitor 5 to be charged with the grid current of the generator lamp. In this case, the oscillations stop and the capacitor 5 is discharged through the resistance 6. Thus, on the resistance 6, a periodically varying potential difference is created, negative for the cathode.

This potential difference is used as a grid bias for a backfire lamp, the grid of which, at a row with the specified offset, is alternately applied

the voltage dt of the coil connected to the anodic circuit.

. Due to the properly selected parameters of self-induction of the coil, the magnitude of the coupling coefficient and the initial working distance of the second variable of 1, (on the grid of the latter, the angle close to 90 is shifted relative to the voltage on the grid of the generator. In the same phase relation is and the anode voltage of the second lamp. The jaTymKa grid of the first lamp is connected to the anode of the second lamp, so the voltage on the generator grid is the sum of two terms shifted in phase by an angle close to 90 °. The relative magnitude of these Laga onpfedel -setochnym an offset sec | ex, lamp periodically varying during relaxation and, Thus, one cycle of the relaxation genbratbr npOXeflMf br fp6kyyu MShsu frequencies.

The subject matter of the invention.

A self-excited generator, characterized in that the grid circuit of the generator is directly connected to the anode of the additional reversing lamp, the grid of which is supplied from the generator variable e. D. s., shifted in phase by an angle close to 90 °, in order to change the frequency.

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