SU55915A1 - Push pull amplifier low frequency - Google Patents

Description

The subject of the invention is a low-frequency push-pull amplifier, which differs from the usual one in that feedback is used to obtain a "two-cycle sequential amplification", which is carried out in such a way that the plus anode source is connected to the midpoint of the output differential transformer, but through the primary winding grid differential transformer, as well as the fact that an additional transformer, which is an input transformer, is included in the break of the common section of the grid bias circuit m transformer.

The drawing shows the cxeiyia switching amplifier. The low frequency to be amplified is supplied via Tr. Transformer}, the secondary winding of which is connected in series with the battery to the grid circuit of the push-pull stage. This low frequency inphase controls the grids of both lamps, resulting in a change in the anode current flowing through the primary winding of the grid differential transformer Tr.2, i.e., the amplifier operates in a single-stroke scheme with two lamps. This is the first amplification cycle.

Further, the amplified low frequency from the secondary winding of the transformer Tr.2 falls again on the grids of the push-pull cascade, but is already again and again amplified by the same amplifier in a push-pull pattern. This is the second amplification cycle.

The in-phase movement of workers: lamp points (occurring during the first cycle of amplification) does not interfere with the operation of the push-pull stage, if it occurs within small limits. The first cycle is a kind of pre-amplification and satisfies this requirement.

However, the first cycle of amplification occurs, as can be seen from the foregoing, in a single-ended scheme and is not possible when working on the bends of the characteristic.

The circuit works with gain mode A; it allows for a sharp increase in the gain factor while maintaining the output power of the cascade.

In the previous experiment, the gain factor, as the author claims, changed from 15 to

66, i.e., more than quadrupled. At the same time, the amplitude and partial characteristics of the amplifier removed after the alteration were quite satisfactory.

The subject matter of the invention.

Push-pull low frequency amplifier, characterized in that plus

The power source of the anodes is connected to the midpoint of the output differential transformer through the primary winding of the grid differential transformer, and the input transformer is connected to the disconnection of the common part of the grid bias circuit.

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