SU458941A1 - Blocking generator - Google Patents

Description

one

The invention relates to the field of radio engineering and can be used in automation, television technology, measurement technology, in particular in personnel and horizontal scanning TVs.

In the known blocking generator, which contains a common emitter transistor, a pulse transformer, one winding of which is connected to the collector circuit, and the other to the base circuit of the transistor, the bias source and two thyristors, limits the synchronization frequency.

The aim of the invention is to expand the limits of the synchronization frequency.

This is achieved by the fact that in the proposed blocking generator, the thyristors are connected in anti-parallel between the offset source and the winding of the pulse transformer connected to the base of the transistor, while the control electrodes of both thyristors are connected to the source of synchronizing pulses.

The drawing shows a functional diagram of the proposed block-generator.

The blocking generator contains a transistor 1 with a common emitter, a pulse transformer 2, one winding 3 of which is connected to a collector circuit, and another winding 4 to the base circuit of transistor 1, a bias source 5, two thyristors 6 and 7 connected in anti-parallel between the bias source 5 and the winding 4 of the pulse transformer 2, the control electrodes of which are connected to the source 8 of clock pulses. In addition, a C-circuit is included in the blocking generator circuit, consisting of a resistor 9 and a capacitor 10.

The proposed blocking generator works as follows.

In the initial state, the block generator is in a known self-oscillatory mode. After the blocking process, the capacitor 10 is discharged exponentially. The occurrence of a synchronizing pulse opens the thyristor: either b or 7, depending on the voltage left on the capacitor 10. At the same time, the capacitor 10 is recharged or discharged to a voltage determined by the bias source 5,

specified on the basis of the required size of the synchronization zone to the larger or smaller side, and the time of the natural discharge of the capacitor 10 varies depending on the frequency of the synchronizing signal. Together

With this, the generation frequency of the block generator also changes, which exactly follows the frequency of the source of 8 clock pulses. Moreover, the pulses of the synchronized blocking generator always lag behind in time

clock pulses. This is a time of

3

varies with the frequency of the synchronization signal.

Subject invention

A blocking generator containing a transistor with a common emitter, a pulse transformer, one winding of which is connected to the collector circuit, and the other to the base of the transistor, a bias source and two thyristors, o t and that, in order to expand the limits of the synchronization frequency, the thyristors included are anti-parallel between the bias source and the winding of a pulse transformer connected to the base circuit of the transistor, with the control electrodes of both thyristors connected to the source of synchronizing pulses.