SU1113885A1 - One-shot multivibrator - Google Patents

Abstract

THE WAITING MULTI-VIBRATOR contains a trigger on two 2I-NOT elements, the S input of which is connected to the startup bus, and the R input with the first pin is the time of the setting resistor and through time the time capacitor is connected to the common bus, characterized in that the duration of the generated pulses, the third element 2I-NOT is entered into it, the output of which is connected to the second pin is the time of the setting resistor, and the first input is connected to the forward output of the trigger, and the control bus connected to the second input of the third element 2I-NOT.

Description

eleven

The invention relates to devices for pulsed technology and is intended for operation in electronic devices.

Known waiting multivibrator containing a key stage on the first Transistor, an element OR NOT, the first input of which is connected to the startup bus, the second - with the collector of the first transistor, and the output through the capacitor - with the base of the first transistor, the element IS-NOT, the first input of which is connected with the control bus, the second input of which is connected to the collector of the first transistor, and the output directly to the emitter and through the inverter to the base of the second transistor, the collector of which is connected to the base of the first transistor ij through the resistor.

A disadvantage of the known device is the structural complexity and a relatively small range of durations of the generated pulses.

Closest to the present invention is a standby multivibrator containing a trigger on two 2I-NOT elements, the S input of which is connected to the trigger bus, and the R input with the first pin of the master resistor and chesez the master of the common bus. the output through the inverter is connected to the second pin of the time of the setting resistor 2j

A disadvantage of the known device is the narrow range of the duration of the generated pulses.

The aim of the invention is to extend the range of the duration of the generated pulses.

The goal is achieved by the fact that a standby multivibrator containing a trigger on two 2I-NOT elements, whose S input is connected to the start bus, and the R input to the first pin of the master resistor time and through the master capacitor to the common bus, are entered the third element 2I-NOT, the output of which is connected to the second pin of the time of the setting resistor, and the first input to the direct output of the trigger, and a control bus connected to the second input of the third element 2I-NOT.

FIG. 1 shows the electrical circuit of the proposed device; in fig. 2 - diagrams explaining his work.

138852

The standby multivibrator contains a trigger on elements 2И-НЕ 1 and 2, a third element 2И-НЕ 3, a time setting RC circuit on a resistor 4 and a condenser 5 connected to between the output of element 3 and the common bus, control bus 6, start 7 and output eight.

th breathing multivibrator works as follows.

Yu In the initial state, bus 7 contains a logical one, the output of element 1 is a logical zero, and the outputs of elements 2 and 3 are logical ones. Condenser 5

fs fully charged n The mode of operation depends on the signal on the control bus 6.

Let logical unit be present on bus 6.

20 Then the device works like a prototype. With the arrival of impulses. Sa trigger on bus 7 trigger flips. On the output bus 8 of the device and on the output of the element 3, logical zeros are inserted. The discharge of the capacitor 5 through the resistor 4 and the element 3 begins. When the voltage on the capacitor is reached below the threshold voltage of the element 2

0, the trigger is reset to the initial state and the formation of the pulse ends. In this case, the pulse duration is determined by the time constant of an RC circuit with R, Cc.

, Let control bus pulses with a duty cycle be applied to bus 6. In this case, as can be seen from FIG. 2, the discharge process of the capacitor 5 is constantly interrupted and the charge

the capacitor is partially restored. As a result, the pulse duration increases and, with a corresponding pulse duty ratio on bus 6, can practically reach

j infinity.

If there is a logical zero on bus 6, the device becomes insensitive to trigger signals.

. Compared with the base object for which the waiting multivibrator is adopted, the invention allows, with greater structural simplicity, to expand the range of durations of the generated pulses by partially recovering the charge by the time of the driving capacitor at the time of interruption of the discharge process.

t /

FIG. 2

Claims (1)

A WAITING MULTIVIBRATOR containing a trigger on two 2I-NOT elements, the S-input of which is connected to the start bus, and the R-input with the first output of the time-setting resistor and through the time-setting capacitor - with a common bus, which is triggered by the fact that, in order to expand the duration range formed pulses, the third element 2I-NOT is introduced into it, the output of which is connected to the second output of the time-setting resistor, and the first input is connected to the direct output of the trigger, and the control bus connected to the second input of the third FIG. 1 1 Π13885