SU78856A1 - Arrangement of linear transient test bench units - Google Patents

Description

The invention relates to devices for linear transient test bench units that simulate the inertial, integrating and oscillating levels of an automatic control system.

The described device contains a DC amplifier with adjustable gain and a separate supply of both the input voltage and the negative feedback voltage to the grids of the first stage.

The DC amplifier circuit is shown in the drawing. The input voltage from the terminals J to 2 is applied to the left grids of the electron tubes L and L2. Negative feedback voltage from resistance RT is applied to the right grids of the same lamps, since the left half of lamps i and lg work like cascades with a cathode output, the voltages on the resistances Ri and R2 will be approximately equal lamp grids. These voltages with the opposite sign are applied to the right lamp grids. Therefore, the potential difference between the cathode and the right grid of the lamp is equal to the difference between the input voltage (i.e., the potential of the left grid relative to the ground) and the feedback voltage (relative to the ground). The resistances and re rollers, so that the right half of the lamps L and L-2 have a large gain factor. The left half of the Lg and L-2 lamps stabilize the operation of the DC amplifier, compensating for the effect of a change in the emission of electrons from the cathodes of the lamps during operation.

The resistances Rs and have a significantly smaller value than the resistances Rz and Re, resulting in an increase in emission, the voltage drop across the resistances Ri and R from the current flowing in the left halves of the lamps increases, which causes an increase in the negative bias on the grids of the right halves of the lamps than and the effect of increasing emissions is compensated.

Signals after amplification in a two-stroke cascade performed on Lz and L lamps arrive at the output stage on L and Lo lamps. The right halves of these lamps serve to generate a negative feedback voltage, which, through the resistances Rs, Ra, Rio and Rn

No. 78856

served on the grid of the lamps L and Lz. Resistance, and R form a potentiometer. By varying the resistance RT, it is possible to adjust the magnitude of the negative feedback, and hence the gain. The output voltage is removed from the terminals i, 2i.

An additional output stage on the lamps L and L, is made according to the cathode follower circuit. In addition to the output terminals 3 E 4, an external feedback potentiometer circuit (resistors Rn, Ris and R) is connected to the cathode load of the cascade in the case when it is necessary to form an oscillatory link:

Adjusting the potentiometers Ru, Ri and Rie, you can set a zero at the output of the amplifier, and adjust the value of the input voltage at the terminals i and 2, which for all units of the stand should be equal to a strictly fixed value.

Subject invention

Device-line units of the stand for the study of transients, for example, and using it with a dc amplifier, in which the method of cathode compensation is applied, adjusting the gain and, separately, feeding the grid of the first stage as the input voltage, and on the negative side of feedback.