SU1228223A1 - Symmetric multivibrator - Google Patents

Abstract

The invention relates to a pulse technique and can be used to generate rectangular pulses. The purpose of the invention is to increase the stability of the pulse frequency and to simplify the device. The multivibrator contains thyristors 1 and 2, locked on a control electrode, a common bus 3, resistors 4, 5, 13 and 14, a power bus 6, transistors 7 and 8, diodes 15 and 16, and zener diodes 17 and 18. The RC-connection shown in the diagram The circuits formed by capacitors 9, 10 and resistors 11 and 12 reduce the response threshold versus temperature, eliminate the extra power source and reduce the number of resistors. 1 il. 6 I th - 6 S (L with IND ND 00 IS

Description

The invention relates to a pulsed technique and can be used to generate rectangular pulses.

The aim of the invention is to increase the stability of the pulse frequency by reducing the response threshold versus temperature, as well as simplifying the device} by eliminating the additional power source and reducing the number of resistors.

The drawing shows the principles. An electrical circuit of the device.

The multivibrator contains the first and the second thyristors 1 and 2 locked by the control electrode, the cathodes of which are connected to the common bus 3, and the anodes through the first and second resistors 4 and 5 with the power bus 6. The first and second transistors 7 and 8 are connected by collectors to the control electrodes of thyristors 1 and 2, and by emitters to the middle points of the first and second consecutive EC circuits of capacitors 9, 10 and resistors 11, 12. The terminals of resistors 11, 12 are connected bus 6, and terminals of capacitors 9 and 10 with control electrodes of thyristors 2 and 1, respectively. Between the control electrodes of the thyristors 1 2 and bus 3, the third and fourth resistors 13 and 14 are connected. The bases of transistors 7 and 8 are connected to the anodes of thyristors 1 and 2 through the directly connected first and second diodes 15 and 16, respectively, and to bus 3 through the first and second back-included zener 17 and 18.

Symmetric multivibrator works as follows.

When the power is turned on, due to the inadequate asymmetry of the charging circuits of capacitors 9 and 10 and the variation of the parameters of thyristors 1 and 2, one of the thyristors opens, and the second remains closed.

Suppose that the multivibrator is set to the position in which the thyristor 1 is closed and the thyristor 2 is open.

Capacitor 10 will not be able to charge, as it is shunted by the first emitter — base of transistor 8, diode 16 and open thyristor 2. Capacitor 9 is charged through resistor 11 from the power supply. Current

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charge of the capacitor 9 confirms the open state of the thyristor 2 and cannot change the state of the multivibrator.

5 When the voltage on the capacitor 9 exceeds the stabilization voltage of the Zener diode 17, the transistor 7 opens. The collector current of the transistor 7 turns on the thyristor 1, and the voltage O on its anode becomes equal to 1 1, 5. V. The diode 15 opens, the voltage on the base, and consequently, on the emitter of transistor 7, decreases in a jump. Voltage drop, approximately

15 equal to the stabilization voltage of the Zener diode 17, through the capacitor 9 the thyristor a 2 is supplied to the control electrode and switches off the latter. Capacitor 9 is discharged through up 20 equating the transition of thyristor 2, opening thyristor 1, diode 15 and transition of the base emitter of transistor 1, the multivibrator is in which the thyristor 1 is open and thyristor 2 is closed.

The capacitor 10 is charged through a resistor 12. When the voltage on the condenser. Tore 10 exceeds the stabilization voltage of the zener diode 18,

similarly, the transistor 8 is opened, the thyristor 2 is turned on and the thyristor 1 is turned off. The multivibrator returns to its original state,. the Capacitor 10 is discharged and capacitor 9 starts a new charge cycle.

Claims (1)

Invention Formula Symmetric multivibrator, containing the first and second thyristors, the cathodes of which are connected to the common busbar, and the anodes are connected to the power bus through the first and second resistors, respectively, the first and second serial KS circuits, the collectors of which are connected to the control electrodes of the first and second thyristors and with the first terminals of the third and fourth resistors, the first and second zener diodes, the first and second diodes, characterized in that, in order to increase the stability of the pulse frequency and simplify the device, the first and second serial RC-tsepiprisoedineny capacitor terminals to the control  1228223 the electrodes of the second and first thyristors through directly connected tori, respectively, resistor first and second diodes and to the common shivvyvodami - to the power bus, and the middle - through the back connected first mi points - to the emitters of the first and second zener diodes, the second the second transistors, the bases of which 5 the conclusions of the third and fourth re-connected to the anode of the first and second. tori connected to a common bus.