SU55494A1 - The method of measuring the cut-off angle of the anode current of lamp generators using a logometer - Google Patents

Description

From the theory of the cascade, which amplifies the modulated high frequency and operates with oscillations of the 2nd kind, it is known that the cut-off angle of the anode current b should be equal to --EO; otherwise, if there are changes in the depth of modulation and inevitably associated undue distortion.

Observation of the cut-off angle I, with which the cascade operates, is usually made by taking readings from several instruments and then counting. The proposed method makes it possible to directly read along the slit of angle iii, which, in turn, makes it possible to continuously monitor the value and immediately take appropriate measures to ensure that it remains unchanged. The method is based on the fact that each value of the angle φ of a pointed cosine-like impulse corresponds to a certain ratio between the amplitudes of the currents of the first / CTI and the second / ω of harmonics.

Really:

mi 1 tg 2

w2 |

I

t,

 - / (t) in

and attitude

mz

is a function of the angle f. Graphically () is shown in

The attached diagram of FIG. 1. As can be seen from this chart,

ratio - when changing f from

30 to 140 °, varies from 1 to 15. Thus, measuring the ratio of the amplitudes or the effective values of the currents of the first and second harmonics, you can measure the angle j).

One possible embodiment of the device is shown in FIG. 2. One or more turns 1 are included. successively into the anode circuit of the lamp generator, the cut-off angle L of the anode current of which is measured. Circuit 7 is inductively connected to circuits 2 to 3. Circuit 2 is tuned to the first harmonic, and circuit 5 to the second. The connection between coil / and circuits 2 and 3, as well as the connection between circuits 2 w. 3 should be as weak as possible, in order to avoid possible reactions. The high-frequency current of the first harmonic is rectified by one of the anodes of the kenotron — and supplied to one of the windings of the meter 5. The capacitance.5 and high-frequency jet coils 7, 7 are used so that only the constant component of the rectified current gets into the winding of the meter 5 first harmonic. The high-frequency current of the second harmonic is rectified by the second anode of the kenohourd 4 and is supplied to the second winding of the meter 5. The assignment of the capacitor 8 and the reactive coils P, 9 is identical with the assignment of the capacitor 6 and the reactive coils 7, 7.

The described device is placed in a metal shield 10, which is grounded. Logometer 5 can be installed anywhere conveniently.

for observation, for example, on the console. The scale of the gauge 5 is graduated directly in degrees of the angle f. Thanks to the use of a logometer, the instrument readings do not depend on the degree of heating of the kenotron, nor on its service life, nor on the force that an anodic current impulse flows through the coil; therefore, it is possible to achieve a high accuracy in measuring the angle f.

The subject matter of the invention.

A method of measuring the cut-off angle of the anode current of lamp generators using a logometer, characterized in that the rectified voltage of the fundamental frequency of the generator and the rectified voltage of the second harmonic are applied to one coil of the gas meter.

. fig.1

SGP

J5 14/3

/ g and

9 8 7 6 5 4 3

.2

-g-Wnr L i L TSTiP J-J