SU155827A1 - - Google Patents

Description

Known relaxers on the avalanche triode, included in the scheme with a combined emitter and base.

The proposed relaxer is characterized in that it contains in the emitter circuit a series-connected dynamic displacement chain and a short-circuited delay line. A shorted delay line is shunted by a resistance equal to the characteristic impedance of the delay line. This embodiment of the relaxer increases the stabilization of the frequency of the pulses.

FIG. 1 shows a relaxator circuit; in fig. 2-scheme of the elements for stabilizing the frequency of output pulses.

The frequency of the output pulses is stabilized using an RC dynamic displacement chain and a shorted delay line connected in series to the emitter circuit of the transistor.

In the avalanche mode, the transistor operates at an increased collector voltage; the power supply voltage must be higher than the breakdown voltage of the collector junction. In this case, when the power source is turned on, capacitance C will begin to charge Vo to close to voltage V ". The collector junction current, passage through the base circuit, increases, and the emitter junction opens. At this moment, a lava-like increase in the current through the transistor begins, resulting in a capacitance discharge on the resistance Rf, an output pulse of positive polarity appears for pnp-type triodes. After the capacitance is discharged, the transistor goes to the closed state and the whole process repeats. Since the duration t of the output pulse

No. 155827-2 -

much less than the charge time of the chain R Cg, then for a non-output pulse the following expression is true:

r Q "In--.

In order for the power dissipated in the transistor not to exceed the allowable one, the following condition must be met:

R .. ,, E

where P (od-permissible power dissipation for the type of transistor used in the generator.

From the formula for the period of the output pulses, it can be seen that the period depends on the mode of the DC relaxor.

The operation of the frequency stabilization elements (Rg C of the chain and the delay line) is as follows.

At the moment of discharge of the capacitance Cd „, the capacitance C, which enters the dynamic distribution circuit, is charged. After the end of the effect of the output pulse, the discharge of this capacitor on the resistance Rg creates a blocking shift of the emitter transition by a time dependent on the parameters of the chain.

In addition, when forming the output pulse at the input of the delay line, a pulse voltage (of negative polarity for the pnp type triode) appears. This pulse, reflected from the charged end of the delay line, changes its polarity. After a time equal to twice the delay time, an impulse (already of a positive polarity) appears at the input of the line, which triggers the circuit. If the constant time t of the chain Rg Cd is an example of the follow-up period of the output pulses, which should be equal to twice the line delay time, the transistor will not open earlier than the appearance of the next reflected pulse at the input of the delay line. Thus, the dependence of the period of the output pulses on the effect of destabilizing factors on the generator circuit is satisfied.

Subject invention

Relaxator on lavioi triode, connected according to the scheme with a combined emitter and base, characterized in that, in order to increase the stabilization of the pulse frequency, it contains in the emitter circuit series-connected dynamic displacement chain and a shorted delay line, bypassing the resistance equal to the wave resistance of the delay line .

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