SU484634A1 - Thyristor magnetic pulse modulator - Google Patents

Description

one

The invention relates to a pulse technique, and in particular to a pulse modulator.

A thyristor-magnetic pulse modulator, containing a source of direct voltage, a charge LC circuit with a key thyristor and a magnetic link with auxiliary thyristor, in which the maximum permissible pulse frequency is limited by the possibility of obtaining the necessary time interval to ensure reliable shutdown of the thyristor.

The aim of the invention is to increase the maximum permissible pulse frequency of the modulator.

This goal is achieved by the fact that a pulse generator, a waiting multivibrator, a pulse separator, and a trigger pulse generator are added to the pulse modulator. The output of the start-up pulse generator is connected via a standby multivibrator to the input of a pulse separator, the first output channel of which is connected to the primary winding of the transformer, the secondary winding of which is connected to the control electrode of the key thyristor, and the second output channel to the control electrode of the auxiliary thyristor.

FIG. 1 shows a functional diagram of the proposed thyristor-magnetic pulse modulator; on fit. 2 - stress diagrams.

The thyristor-magnetic pulse modulator contains a source of constant voltage, a charging LC circuit consisting of inductance 2 and a capacitor 3, a key thyristor 4, a magnetic link 5, auxiliary thyristor 6, a generator of starting pulses 7, a standby multivibrator 8, a separator pulses 9, a starting pulse shaper 10 and a transformer I, the primary winding 12 of which is connected to the first output channel of the pulse separator 9 through the corresponding channel of the trigger pulse generator 10, and the secondary winding 13 to the controlling electrode key thyristor 4.

Powered pulse modulator as follows.

The t / mii supply voltage from a constant voltage source is simultaneously applied to the charging LC circuit, start pulse generator 7, standby multivibrator 8, pulse separator 9, and trigger driver 10. Start pulse generator 7 with pulse t / r (see Fig. 2, a) starts the waiting multivibrator 8, which gives a rectangular pulse / zhd at its output

(see Fig. 2.6), the duration of which is selected from the ratio; Gzh zar + out, where 7zar - the charging time of the capacitor 3; , - thyristor off time 4.

The impulse / 7 times from the output of the waiting multivibrator 8 is placed on the BULS separator 9, where it is differentiated (see Fig. 2, c) and is divided into two output channels. The first output channel to the shaper 10 imiuls generator passes the Lop signal (see | Fig. 2, d), corresponding to the leading edge of the pulse from the output of the standby multivibrator 8, and the second output channel to the trigger driver 10 passes the t / f signal ( see Fig. 2, d), corresponding to the falling edge of the pulse from the output of the waiting multivibrator 8.

The first channel of the pulse separator 9 n of the trigger pulse generator 10 is designed to start the thyristor 4 through the transformer 11, and the second channel - to start the thyristor 6.

After a start pulse is applied (see Fig. 2, d) to the thyristor 4, the latter opens, and the process of resonant charge of the capacitor 3 begins through the charge inductance 2 (see Fig. 2, e).

After completion of the resonant charge process of the capacitor 3, when the charge current flowing through the thyristor 4, reverses its direction, and the transition of the cathode-anode of the thyristor 4 occurs abrupt voltage equal to about Umn (see. Fig. 2, g) which lifts up the thyristor 4. The duration of this voltage applied to the transition of the cathode of the thyristor 4 is determined by the time required for its complete and reliable shutdown.

Only after the termination of the described processes, when the thyristor 4 is reliably turned off, a start impulse comes through the second channel to the control electrode of the thyristor 6. The thyristor 6 is unlocked, and the resonant discharge of the capacitor 3 to the next magnetic field occurs.

modulator compression unit.

The next impulse to start the thyristor 4 must be supplied only after the expiration of the time Gwic (Gwic - the time of action of the reverse voltage on the thyristor 6, which is determined from the condition of its complete deactivation).

Thus, the maximum pulse frequency at the output of a thyristor-magnetic pulse modulator is determined by the frequency of the trigger pulse generator 7 and is limited by the relation:

J ate vy, r-goke; Where / times

capacitor discharge time 3.

Subject invention

A thyristor-magnetic imulse modulator containing a source of direct voltage, a charge LC circuit with a key thyristor and a magnetic link with an auxiliary thyristor, characterized in that, in order to increase the maximum permissible pulse frequency of the modulator, the keto additionally entered a trigger pulse generator, a standby multivibrator, a pulse separator and a trigger pulse driver, while the output of the trigger pulse generator is connected to the pulse separator through a standby multivibrator, he first output channel coupled to a primary winding of the transformer, the secondary winding is connected to the control electrode of the thyristor key, and the second output channel - to the control

auxiliary thyristor electrode.