SU514417A1 - Standby Multivibrator - Google Patents

Description

one

The invention relates to radio engineering and can be used in radio installations with remote stepwise switching of the pulse duration.

A known waiting multivibrator on transistors with collector-base positive feedbacks, containing in one of the feedback circuits, several parallel-connected time of driving capacitors.

However, the known multivibrator does not have the ability to vary the duration of the voltage generated by them using control signals.

In order to change the duration of the generated pulses with the help of control signals in series with each time the driving capacitor, the collector-emitter junction of the additional transistor, shunted in the opposite direction by the diode, the bases of the additional transistors, are connected to the sources of control signals, and the base of the closed source state The transistor and the base of the additional transistors are connected to the source of bias through the respective resistors.

The drawing shows the electrical circuit of the multivibrator.

The waiting multivibrator contains transistors 1 and 2 connected by positive feedbacks. In about. No.1 of the Tsei Nibono feedback loop B1 is the time setting masterpieces 3 and 4. In series with the capacitors 3 and 4, collector-emitter junctions of the transistors 5 and 6 are included. back-clamped diodes 7 and 8. The bases of transistors 5 and 6 are connected to the sources of control signals (not shown) connected to terminal 9. The base of transistor 1 and the base of transistors 5 and 6 is closed through resistors 10- 12 are connected to an offset source connected to terminal 13.

There can be any number of capacitors, depending on the number of necessary frequencies generated by the waiting lm slider. The diagram shows for simplicity two times of setting the capacitor 3 and 4.

Waiting multivibrator works as follows.

In the initial state (before the arrival of the trigger at input 14), transistor 1 is closed, and transistor 2 is open and saturated. Transistor 5 is saturated, as its base voltage is applied to the base voltage, and transistor 6 is locked by the bias voltage applied to its base. Condors 3 and 4

0 charged wives.

After the arrival of the triggering pulse Horo to the input 14, transistor 1 opens and transistor 2 closes. The capacitor 3 is discharged along the circuit: collector emitter of transistor 5 - collector emitter of the transistor 1 - housing - power supply - resistor 15. Due to the fact that transistor 6 is negative, the discharge of the capacitor 4 does not occur.

After capacitor 3 is discharged, transistors 1 and 2 return to the initial state, the capacitor 3 is charged along the circuit: the right is the capacitor 3 - base-emitter junction of transistor 2 - body - power supply - resistor 16 - diode 7 - left capacitor plate 3 .

If it is necessary to switch the pulse duration of the multivibrator, the control voltage is applied to the base of the transistor 6, the capacitor 3 is turned off, and the capacitor 4 is turned on.

Formula and 3 about b) e te

Pending multivibrator on transistors with collector-base positive feedbacks, containing several parallel-connected setpoint capacitors in one feedback circuit, characterized in that, in order to change the duration of the generated pulses using control signals, in series with each setpoint capacitor included collector-emitter junction of an additional transistor, a diode-shunted in the opposite direction, the base of additional transistors connected to the source by control signals, the base of the closed in the initial state of the main transistor and the base of the additional transistors are connected via a corresponding resistor to the source smsn1.

esi3