SU42614A1 - Amplifier - Google Patents

Description

Presently existing amplifiers for direct currents (voltages) are usually made on resistances without transient capacitances with compensation for a large positive potential applied to the grid of the amplifier lamp by switching on individual batteries and resistances or according to the Loftine and White scheme. The execution of these circuits rests on the need for very careful selection of all resistances and at the exceptional constant voltage of the supply batteries, which practically does not allow the implementation of a constant current amplifier of more than two, a maximum of three cascades, and prevents the power supply of the entire amplifier with rectified current.

The present invention relates to a device of a direct current amplifier on resistances, which makes it possible to obtain a gain from zero frequencies to high inclusive.

In the specified amplifier, the electrical circuit of which is shown in the same line, ordinary amplifying lamps having screening grids or pentodes with direct cathode heating or heating are used as amplifying lamps, and the anode can be supplied with a rectified current in both cases. In this scheme, a screening grid is used as a control, and some small negative potential from the same high voltage source is set to the closest one to the cathode.

For the connection of individual cascades, only one resistance was applied, which is common to the anode circuit of the previous lamp and the grid circuit of the subsequent lamp.

Therefore, a positive voltage equal to that of the previous lamp is applied to the shielding grid of the subsequent lamp. And since for the normal operation of the pentode, the voltage on the shielding grid may be equal to or slightly less than the voltage of the anode, all the lamps will work in normal mode.

The work of the amplifier is as follows. A change in the potential on the control grid of the first lamp will cause a corresponding change in potential on the resistance in the anode of this lamp, and since the screening grid of the second lamp is connected to the same resistance, hence the change in its potential, which will cause a change in potential on the resistance in the anode of the second lamp and etc.

No distortion during amplification should occur here. The amplifier works very steadily from a single power supply and allows the inclusion of a larger number of stages. The proposed scheme can be successfully applied as:

1) DC amplifier and voltage amplifier;

2) a low-frequency amplifier, for example, for a sound movie;

3) a high frequency amplifier;

4) broadband television amplifier;

5) amplifying circuit in the measuring technique;

6) pulse amplifier of any shape without distorting the latter.

The subject matter of the invention.

A direct current amplifier, shielded lamps, characterized in that a shielding grid is used as a controlled grid, and a negative potential is applied to the grid closest to the cathode, and only one resistance common to the individual stages of the previous lamp and chain shielding mesh follow lamp.

. - (; I

No

--i i