SU391712A1 - QUICKLY MULTI VIBRATOR - Google Patents

Description

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The invention relates to a pulse technique and can be used as a generator of rectangular pulses in computers and automation devices.

A high-speed multivibrator on transistors with collector-base connections is known, containing one time a driving resistor connected by one lead to the bases of transistors via two semiconductor diodes, and two additional semiconductor diodes.

The purpose of the invention is to increase the reliability and reduction of circuit elements. For this, another pinout time of the master resistor is connected via additional semiconductor diodes to the collectors of the multivibrator transistors.

The drawing shows a circuit diagram of the proposed high-speed multivibrator.

It contains transistors / and 2, the time setting resistor 3, one output of which through diodes 4 and 5 is connected to the bases of the transistors. The second terminal of the resistor 3 is connected to the collectors of the transistors through diodes 6 to 7. The diode 4 and the base of the transistor 2 are connected via a capacitor 8 to the collector of the transistor /. The diode 5 and the base of the transistor 1 are connected via a capacitor 9 to the collector of the transistor 2. The collector circuits of the transistors Y and 2 include resistors 10 and //.

In one of the quasi-stable states, the transistor (is in saturation mode, transistor 2 is in cut-off mode, capacitor 8 is discharged through diode 4, resistor 3, diode 7, resistor Jij power source, and emitter-collector junction of a saturated transistor /. During the discharge time of the capacitor 8, the diodes 5 and b are in the closed state, since their p-junctions are shifted in reverse

direction. The transistor (s) is in saturation under the action of the charge current of the capacitor 9, which flows through the resistor (V, power source, the emitter-base junction of the saturated transistor).

As the capacitor 8 is discharged, the potential of the base-emitter of transistor 2 decreases and as soon as the unlocking potential becomes equal, transistor 2 opens. By this time, the capacitor 9 is charged, the current in the base of the transistor / stops, and the transistor / closes.

Transistor 2 opens under the influence of the charge current of capacitor 8, which flows through the circuit of resistor 10, the power source, the emitter-base junction of transistor 2. Capacitor 9 discharges diode 5, resistor 3, diode 6, resistor 10, power source, emitter-collector junction of saturated transistor 2. Next, the processes are repeated.

The scheme of the proposed high-speed multivibrator makes it possible to significantly reduce the value of resistor 3 (up to 6-7 clods at resistance values of resistors 10 and 11 1 clods), with relatively large capacitances of capacitors 5 and 9 (up to 500 pf.

At the same time, a sufficiently large steepness of the leading front of the pulse is maintained and the frequency of auto-oscillations in the mode of self-excitation is high (up to 250 kHz at the MP16B transistors).

The amplitude of the output pulse of the multivibrator is close to the value of the supply voltage with the ratio of the values of resistors 3, 10 and // 3 3 ,, (, 10 and -the values of the resistances of resistors 3, 10 and //).

Subject invention

A multivibrator on transistors with a collector base, containing one time the driving resistor connected by one pin to the bases of the transistors through two semiconductor diodes and circuit elements, another output time of the resistor is connected via additional semiconductor diodes to the collectors of the multivibrator transistors.

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