SU1564712A1 - Multivibrator - Google Patents

Abstract

The invention relates to a pulse technique and can be used to generate rectangular pulses. The purpose — simplification of the multivibrator — is achieved by the fact that the capacitive element of the integrating RS circuit is designed as a divider on capacitors 4, 5, the midpoint of which is connected to the inverting input of the operational amplifier 1, and the terminals to the power supply 2 busbars The circuits are made in the form of a divider on resistors 8, 9, the midpoint of which is connected to the non-inverting input of the operational amplifier 1, and the terminals to the buses of the power supply 2. 2 Il.

Description

FIG. one

The invention relates to a pulse technique and can be used to generate rectangular pulses. The purpose of the invention is to simplify the multivibrator.

FIG. 1 is a schematic diagram of a multivibrator; in fig. 2 - Stress diagrams.

The multivibrator contains an operational amplifier 1, a power supply 2, an integrating RC circuit, a resistor 3 containing one connected to the output of the operating amplifier — Tel 1, and the other to its inverting input — and a divider on the capacitors h, $, which is midpoint to the inverting input of opamp 1, and its leads to the power supply buses, and a differentiating circuit containing a capacitor 6 connected by a single terminal through a limiting resistor 7 with an output operating voltage (gel 1 and the other with A non-inverting input, and a divider on resistors 8, 9, a midpoint connected to the non-inverting input of operational amplifier 1, and its leads to power supply buses, output bus 10 connected to the output of operational amplifier.

Multivibrator works as follows.

Let the power source 2 be turned on at the initial time t0 (Fig. 2a). The voltage at the midpoints of the dividers will be equal to half the supply voltage (Fig. 26, c). Let, as a result of fluctuations at the output of the operational amplifier 1, the voltage U of negative polarity begins to increase. Due to positive feedback, an increase in output voltage occurs as an avalanche. As a result, U -E,. U –E, U 0 “Capacitors, 5, during the formation of the front do not have time to noticeably recharge. After the end of the pulse front, the capacitors C, 5 begin to recharge.

about

50

five

0

through the resistor 3, and the capacitor 6 is recharged through the resistors 7, 8, 9. The resistor 7 serves to reduce the voltage on the non-inverting input of the operational amplifier 1. The voltage at the midpoint of the divider on the resistors 8, 9 (on the non-inverting input of the operational amplifier 1) increases over time exponentially (Fig. 26), and at the midpoint of the divider on capacitors k, 5 (at the inverting input of opamp 1) decreases according to the same law (Fig. 2c). At the moment of time t., When the value of these voltages becomes equal, the output voltage of the operational amplifier 1 changes abruptly and reaches the value U + Е. Further processes proceeding in the circuit are similar to those considered.

At time t2, the cycle of forming the oscillation period of the multivibrator is completed.

Thus, the replacement of a resistive element by a divider on resistors, and a capacitive one by a divider on capacitors, made it possible to exclude one power source.

Claims (1)

Multivibrator containing an operational amplifier whose output is connected via an integrating RC circuit to an inverting input and through a differentiating RC circuit to a non-inverting input, characterized in that, in order to simplify the multivibrator, the capacitive element of the integrating RC is the circuit is made in the form of a divider on capacitors, the midpoint of which is connected to the inverting input of the operational amplifier, and its conclusions to the corresponding buses of the power source, the resistive element of the differentiating RC circuit more completely in the form of a divider on resistors, - the midpoint of the operational amplifier connected to the non-inverting input, and its conclusions - with the corresponding power supply buses.