SU552673A2 - Standby Multivibrator - Google Patents

Description

The invention relates to a pulse technique and can be used to form rectangular pulses, dividing the pulse repetition rate.

According to the main author. St. No. 323852 is known for the oncoming multivibrator, made on three transistors, eight resistors and one capacitor. The third transistor and two resistors in the circuit of its base and collector serve to reduce the capacitance during the generation of long duration pulses.

The purpose of the invention is to reduce the recovery time of the suspender, its multivibrator, which is important when using the standby multivibrator as a divider of the pulse repetition frequency received at its input. The maximum division factor "max is determined by the formula

res

1 +

and

/ g „

2 where / all - recovery time of the waiting multivibrator;

ta - the duration of the pulse generated by the waiting multivibrator.

From this expression it can be seen that reducing tjioc allows to obtain a larger maximum value of the division factor.

To achieve the goal, in the proposed multivibrator, a diode is inserted, the anode of which is connected to the collector of the input transistor, and the cathode is connected to the collector of the transistor of the opposite conductivity type.

The drawing shows a diagram of the waiting multivibrator.

The standby multivibrator contains transistors 1, 2 with pp conductivity and transistor 3 with pp conductivity, capacitor 4, resistors 5-12 and an additionally inserted diode 13 connected by the anode to the collector of transistor 1 and the cathode to the collector of the transistor 3. The introduction of diode 13 causes the capacitor 4 to be charged to the open time of transistor 2 and, accordingly, transistor 3 to source voltage, respectively, through the open transistor 3, diode 13, base-emitter junction resistance of transistor 2 and resistor 8. constant recovery time becomes significantly shorter than the recovery time constant in the known waiting multivibrator:

  (7 f. G AS) -4 BOC (K, s + D, s + be. + RS) C4,

where is yours - constant time restored30 nor known waiting multivibrator:

3

Yours is the constant of the recovery time of the proposed standby multivibrator;

Rf - resistor 7; RS - resistor 8;

Kbeg - direct resistance of the base-emitter transition of the transistor 2.

Lekaz - resistance of the open transistor 3;

Kl1z - pr my resistance diode 13. Since

. +. C + BE., +) “,

then TwosS air force.

The technical and economic effect of the introduction of a diode is to reduce the recovery time of the multivibrator, which allows for a given duration of the output pulse to obtain a large division ratio of the repetition frequency of the input pulses.

Claims (1)

Invention Formula Waiting multivibrator auth. St. No. 323852, characterized in that, in order to reduce the recovery time, a diode is inserted, the anode of which is connected to the collector of the input transistor, and the cathode is connected to the collector of the transistor of the opposite conductivity type.