SU769710A1 - Driven multivibrator - Google Patents

Description

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The invention relates to a pulse technique, can be used in a pulse device exposed to a pulse noise with a pulse duration of less than 10 microseconds. The indicated, waiting multivibrator can be used both in the ground and in the onboard radio equipment.

Known waiting multivibrator containing two transistors connected by emitters, time specifying a capacitor and mode resistors. One of the resistors is located in the emitter circuit, thereby providing feedback on the emitter circuit. The negative input signal is fed through a capacitor and a diode to the collector of the first closed transistor and through time the driving capacitor to the base of the second open transistor, where the voltage of the power source 1 is also supplied through a resistor.

The disadvantage of this standby multivibrator is its low noise immunity, which leads to triggering and producing a false signal in the presence of noise at the input.

Known waiting multivibrator containing two transistors, the time setting and the separation (input) capacitors, the input diode and the mode resistors 2.

The known device has a number of disadvantages. The first is its low

5 noise immunity; it is enough to produce a noise of a certain amplitude and small duration at its input, as it will work and give a false signal. The second disadvantage of the prototype is the need to have two power sources, which significantly reduces the possibility of its use.

The purpose of the present invention is to eliminate the false signal from the waiting

15 multivibrator when exposed to impulse noise, i.e., increasing its noise immunity.

To achieve this goal, a multivibrator containing input and output transistors, the emitters of which are connected to a power source, which is connected through resistors to the bases of these transistors, whose collectors are connected to each other and another power source, capacitor, resistors, diode, resistors Two diodes are introduced, a threshold element and a transistor, the emitter of which is connected to the diode anode, one output of the threshold element and a common bus, which through a chain consisting of parallel-connected condensates A resistor and a resistor are connected to the base of the inserted transistor and to the cathode of the second diode, the anode of which is connected to the power supply bus through a resistor, and through the third diode to the cathode of the first diode, another output of the threshold element and collector resistors of the main transistors the resistor is connected to the base of the output transistor.

In the waiting multivibrator, the threshold element can be made on the basis of a chalcogenide glassy semiconductor.

The drawing shows a schematic diagram of the device.

The proposed standby multivibrator contains transistors 1-3, dividing diodes 4, 5, reference diode 6, glassy semiconductor 7, capacitor 8, resistors 9-16. The collectors of the transistors are connected through the corresponding mode resistors 11, 13 to one pole of a glassy semiconductor, the other pole of which is connected to the housing.

The glassy semiconductor is polled by current through mode resistor 12 and diode 4. The signal to the base of transistor 3, to which capacitor 8 and resistor 16 are also connected, is removed from diode 4 through diode 5. The collector of transistor 3 is connected through mode resistor 15 to the base of transistor 2 and to the resistor 14. The emitters of the transistors 1, 2 are connected to the positive power bus. The input signal is supplied to the resistor 9 connected to the base of the transistor 1 and to the resistor 10.

The proposed standby multivibrator works as follows.

Prior to the input of the negative signal, the glassy semiconductor 7 is in a low-resistance state, the transistors 1, 2 are closed with positive potentials of +5 V, and the transistor 3 is closed by an almost zero voltage at its base.

A negative input signal with a duration of about 10 microseconds places the glassy semiconductor in a high resistive state. The capacitor 8 through the resistors 12 and 16 is charged before the voltage of the unlocking of the transistor 3, and the transistors 3 and 2 are opened. After a time of approximately 20 ms, the glassy semiconductor goes back to low-resistance, respectively, the transistors 3, 2 and the capacitor 8 are closed discharged through resistor 16. The device is again ready for operation.

The input signal delay time is determined by the charge time of the capacitor 8 through resistors 12 and 16 to open voltage 1, raisistor 3 and the time to turn the glassy semiconductor into a low-wiring state.

Impulse noise with a duration of less than 10 microseconds does not trigger this device, since the glassy semiconductor does not in this case become high-resistance.

Compared with known standby multivibrator circuits, this circuit

has a significant advantage in connection with the implementation of a single transistor circuit - a threshold (in duration) element based on a chalcogenide glassy semiconductor with

control circuit. A glassy semiconductor has threshold (in duration) properties and can, when exposed to pulsed noise of less than 10 microseconds, be stored

in it information.

The proposed connection of the chalcogenide glassy semiconductor to the input of the transistor, to which the time-setting capacitor is also connected, does not allow to receive a noise-proof waiting multivibrator, which works only with sufficiently long input signals.

Therefore, compared with the well-known waiting multivibrators, this

Multivibrator has a higher noise immunity.

Claims (2)

1 .. A standby multivibrator containing input and output transistors, the emitters of which are connected to the power supply bus, which is connected through resistors to the bases of these transistors, whose collectors are connected to each other and to another power supply bus, capacitor, resistors, a diode that is different the fact that, in order to eliminate the spurious signal under the influence of impulse noise, it introduced two diodes, a threshold element and a transistor, the emitter of which is connected to the diode anode, one output of the threshold element and a common bus that, through a chain of parallel connected a capacitor and a resistor connected to the base of the inserted transistor and to the cathode of the second diode, the anode of which is connected to the power supply bus through a resistor, and through the third diode to the cathode of the first diode, another output of the threshold element and the collector resistors of the main transistors, and the collector of the injected transistor is connected through a resistor to the base of the output transistor. 2. Multivibrator according to claim 1, characterized in that the threshold element is made on the basis of a chalcogenide glassy semiconductor. Information sources, taken into account in the examination 1. Circuits with semiconductor devices under the general editorship of R. M. Malinin, Military Publishing House of the USSR Ministry of Defense, Moscow, 1960, p. 83 2. Fundamentals of pulsed and digital technology, M., “Soviet Radio, 1975, p. 197 (prototype). fff in 9 -K11 one 0 (i p / 5 /five th " one one