SU531261A1 - Standby Multivibrator - Google Patents

Description

(54) WAITING MULTI VIBRATOR

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The invention relates to radio engineering and can be used in automation devices and pulse technology.

A waiting multivibrator is known, which contains a trigger on two transistors of opposite conduction types, a single junction transistor whose emitter is connected to the midpoint 1 of the C circuit, and a G1J power supply. However, the known multivibrator is characterized by insufficient stability over a wide range of delay times.

The aim of the invention is to increase stability over a wide range of delay times.

To do this, in a standby multivibrator containing a trigger on two transistors of opposite conductivity types, a single junction transistor, the emitter of which is connected to the midpoint of the PC circuit, and an OT power supply, the emitter of the first transistor of the trigger is connected to the first base of the single junction transistor and through a negative pole resistor power supply, capacitor time setting RC circuit

connected to the emitter of the second transistor of the trigger and through a resistor to the positive pole of the power source; the collector of the second transistor of the trigger is connected to the second base of the unijunction transistor.

The drawing shows the electrical circuit of the standby multivibrator.

The standby multivibrator contains a trigger on transistors 1 and 2 opposite to conduction types, a single junction transistor 3, the emitter of which is connected to the midpoint of the PC circuit consisting of a capacitor 4 and a resistor 5, and a power source 6.

The trigger transistor 1 emitter is connected to the first base of the single junction transistor 3 and through the resistor 7 to the negative pole of the power source 6. The capacitor 4 is the driving PC circuit connected to the emistor of the transistor 2 trigger and the resistor 8 to the positive pole of the power source 6. The collector of the transistor 2 connected to the second base of the unijunction transistor 3.

The waiting multivibrator works as follows ..

After switching on the power source 6, the multivibrator is automatically reset due to the charge of the capacitor 4 along the circuit: plus power source 6, resistor 8, capacitor 4, open junction emitter - base of the single junction transistor 3, resistor 7, minus power source 6,

The voltage pulses released at resistors 7 and 8 block the transistors 1 and 2, setting the trigger to the closed state. Since the collector of transistor 2 and, therefore, at the second base of the unijunction transistor 3, the voltage is zero, the emitter-first base of transistor 3 is open and the capacitor 4 is charged almost to the voltage of the power supply circuit 6. So the original (stable) standby multivibrator state.

From the moment the trigger pulse arrives at the input 9 of the multivibrator, a 4-delay delay starts. In this case, transistors 1 and 2 of the flip-flop open, capacitor 4 begins to discharge, closing the transition emitter - the first base one of the transition transistor 3.

Since the voltages of the capacitor 4 and the power source 6 are turned on counter, the voltage applied to the closed emitter-first junction of the single junction transistor 3 will be determined by their difference and increase to the voltage of the emitter-first junction as the capacitor discharges four.

After unlocking the unijunction transistor 3, the capacitor 4 is recharged through resistors 7 and 8 to Castro until the voltage of the power source 6 is selected. A separate pulse on the resistors 7 and 8 will close the pulse for the transistors 1 and 2 of the trigger and reset it.

The proposed pending multivibrator compared with the prototype provides 2-4 times higher duration and stability of the delay.

Claims (1)

1. US Patent No. 3349255, cl. ZO7V8 .5 publ. 31.1O.66. (prototype).