SU851506A1 - Pulsed nanosecond transformer - Google Patents

Description

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The invention relates to pulsed high voltage transformers of the nanosecond range, designed to generate and transmit rectangular voltage pulses in various radio devices, in particular, to the pulse moduli.

Also known are power transformers, an operation in impulse modulators with an artificial line, designed to form and transfer rectangular impulse voltages modulating high-frequency ones. transmitter oscillations 1.

Known pulse transformer containing a toroidal magnetic conductor and wound on it primary and secondary windings. Winding made with wires. For the purpose of reducing the decay of the pulse of pulses, the secondary winding has additional turns wound in the direction of its continuation and with this the direction of winding these turns back to the direction of the secondary winding. Since the magnetic cores have a scatter of pulsed magnetic characteristics within the tolerance (reaching the order of + 20%), such a scatter also has a transformer in terms of the magnetisation current. In order to achieve the same optimal shape of the peak of the pulse for the product series, the transformers are adjusted by selecting the number of additional turns 2}.

However, due to the oncoming switching on of additional turns relative to the main turns of the secondary winding, along with a decrease in the decay of the apex, the amplitude of the output pulse decreases. Additional coils increase the geometric dimensions (length, gauge) of the windings

ts and SINGLE lead to an increase in transformer dissipation inductance. Therefore, in addition to the decrease in ashtuda, the additional rounds lead to an increase in the duration of the fronts. In addition, adjusting the transformer with changing the number of turns is inconvenient and dangerous, since the windings are non-insulated. And after applying an insulating or moisture-proof coating, access to the windings ceases and adjustment becomes impossible. For the same reason, after the modulator is assembled, no additional adjustment is possible, the need for which

The swarm is caused by the fact that the parameters of the artificial line and the load also have variations within their tolerances. This leads to the fact that the optimal form of the output pulse can be achieved only by the method of preliminary selection of transformer cores and modulator elements according to parameters, which increases the labor intensity and cost of adjustment work.

The purpose of the invention is to improve the characteristics of the pulse.

The goal is achieved by the fact that the transformer is equipped with an adjustable choke, the primary winding of the transformer is made of high-voltage coaxial cable, the choke is connected at one end to the braid of the cable, and the other is connected to the end of the cable core and is installed on the transformer.

FIG. 1 and 2 the proposed transformer, electrical circuit; in fig. 3 - the same appearance.

The choke 1, installed directly on the transformer 2 in order to achieve the minimum length of the connections, has a trimmer for adjusting the inductance.

The transformer works as follows.

In the interval between pulses, the artificial line is charged through the primary winding of the transformer. The potential of the anode of the line becomes equal to E, the potential of the anode of the charging device. The same potential is acquired by the cable sheath. The potential difference between the dwelling and the sheath during this period is 0. When a pulse is formed, the thyratron 3 opens and the line is discharged through the primary winding of the transformer. At the moment when the pulse begins, the potential A of the core U (and the potential of the end B of the braid Ugo becomes equal to O, because they are connected to the ground through the thyratron 3. The increasing magnetic flux created in the core when the line is discharged induces an electromotive force on the secondary leads windings, and at the ends of the cable braid. The core and the braid form windings with a ratio of 1: 1 turns, therefore, at a potential of 0.5E, the potential is 5E. Thus, at the moment of the beginning of the pulse between the core and the braid of the cable, a voltage is instantly applied

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As a result of this, a transient process arises in the circuit of the cable core - braid of the cable - adjustable throttle - of the cable core. The transient current during the pulse duration increases exponentially from 0 to a certain value that can be adjusted with the help of throttles. Since this current flows through the primary winding and coincides in direction with the operating current of the transformer, the increase in the magnetic flux in the core is accelerated. By twisting or unscrewing the throttle trimmer, it is possible to set a transient foKa value such that it compensates for the magnetization current lagging from the linearly increasing function, thus eliminating the decay of the vertex.

The use of the invention makes it possible to obtain a drop in the peak of the pulse to 0% with an improvement in amplitude and fronts, to ensure the possibility of adjusting the transformer at any stage of production, as well as in the modulator.

The need for prior

0 selection of elements in the parameters disappears. The labor intensity decreases and the safety of assembly and adjustment works increases.

Claims (2)

1. USSR author's certificate No. 636692, cl. H 01 F 19/08, 1978. 2. Ivanov A.5. and Sosnovkin L.N. 5 Pulse transmitters SEC. M., Soviet Radio, 1956, p. 479-490. /  4.1 l: ii X Uj