SU58643A1 - Tube oscillator - Google Patents

Description

A copyright certificate No. 50900 on the same inventor describes a method for obtaining electrical oscillations of a frequency that uses free-damping oscillations of a weakly damped resonator (for example, a piezo-quartz block, a tuning fork, etc.) excited by short pulses from an outsider. energy source.

In a number of cases, damped oscillations cannot be unconditionally replaced, in particular for measurement purposes (frequency standards), since such oscillations have a number of disadvantages. However, under certain conditions, damped oscillations can sometimes be used along with undamped oscillations. These terms are as follows:

1, The generator should give a continuous series of oscillations. The frequency of the impulses that excite damped oscillations should be such that, by the time c, the amplitude of the oscillations has time to decrease by a small amount.

2. Every new fading oscillation that arises should be about

phase continuation of the previous oscillation.

Under these conditions, it is possible to obtain a continuous series of oscillations of the type of continuous, modulated by the frequency of the oscillating pulses. The modulation depth will obviously be the smaller, the more often the pulses are applied and the smaller the decrement of oscillations of the excited resonator. So, for example, taking the decrement of quartz oscillations equal to 10, we obtain, at a frequency of 100 kHz and 100 pulses per second, a decrease in amplitude before the new pulse by 10%. At 20 pulses, this decrease will be equal to 50%.

The conditions can be implemented using a device whose schematic diagram is shown in FIG. one.

The oscillating system here is a piezoquartz rod 5, but other weakly damped resonators can be used. Short excitation pulses are generated by the pathogen 15 and excite the piezoquartz rod by means of electrodes 1 and 2; rod 5 thus oscillates in series of damped oscillations. The frequency of the series is equal to the frequency of the pulse of excitation.

The alternating potentials, but the surfaces of the piezoquartz rod, are removed by means of electrodes 3 and 4 and are fed to the input of an amplifier 6, operating in a generator mode with independent excitation.

In order for the iB of such a system to meet the conditions mentioned above, it is necessary for the phase of the excitation pulses to be controlled by the oscillations resulting from the output of amplifier 6. For this, the output of amplifier 6 is connected (see the dotted line in Fig. 1) with the help of an appropriate device with the generator of impulses 15. For such a control, the system as a whole will work as a fading generator, their oscillations of a constant frequency.

Various schemes of such generators are possible.

Consider the circuit shown on the fit. 2

Here, the exciter lamp 15, quartz 5 and lamp 6 constitute in the aggregate a piezoquartz oscillator, which, in the presence of feedback 9, is capable of producing continuous chauffeurs (a modified Kedy scheme). When the driver lamp 15 of the exciter is locked with a negative grid bias, there are no oscillations. To excite oscillations, the grid of this lamp is periodically and for a very short time & m positive potential, during which oscillations will have time to arise and increase to the required amplitude. The drawing shows a method for applying a positive potential by periodically discharging a capacitor 8 through a glow lamp 7. Other methods can be used, for example, discharge through a thyratron, mechanical switches, etc. The oscillation of individual pulses is synchronized by the individual quartz via feedback (capacitive or inductive). The oscillatory circuit 10 in the circuit of the anode of the lamp 6 is configured

on the required oscillation frequency of the quartz rod.

On flash 3 shows a modified self-excited oscillator circuit. A glow lamp 7 is connected to the anode of the lamp circuit 15, as a result of which the anode supply, and hence the generation of oscillations, occurs only at those moments when the capacitor 8, having charged through a large resistance 12, acquires the potential of ignition of the lamp 7; then its discharge will begin through the last and through the anode circuit of the lamp 15. The resulting short oscillatory pulse is transmitted, as in the previous scheme, through the electrodes 1 and 2 to the quartz rod 5.

In the circuit depicted in FIG. 4, the pathogen is assembled according to the scheme of a conventional tamm generator operating in a discontinuous mode. The frequency of the oscillations generated is determined by setting the circuit 10 of this generator. The oscillation of the generator with the oscillations of quartz is synchronized either by feedback between the lamps 15 and 6 or by tightening the resulting oscillations by the oscillations of the potential at the anode of the lamp 15 created by the charges on the electrodes 1 and 2.

FIG. 5 shows one of the possible pulsed tuning-fork circuits, based on the principle of intermittent generation of the lamp 15. It is advisable to make the biasing of 1-magnet 13 necessary for the correct operation of the entire generator by the anode current of the lamp 15. Then during the time when the lamp 5 is locked with negative grid offset, there will be no magnetic field. At this time, the tuning fork will oscillate freely. For the same purpose, the magpit 14 do. Must be so far from the tuning fork that its field may have the least effect on the frequency of the latter. The small amount of energy delivered by the tuning fork to the lamp 6 can be increased by additional amplifying stages.

The subject matter of the invention.

The lamp generator of damped oscillations with self-excitation, in which