SU936394A1 - One-shot multivibrator - Google Patents

Description

(54) ESTABLISHER

one

The invention relates to a pulse technique and can be used in automation systems as a time relay operating under conditions of increased electrical noise.

A one-shot is known, containing a dovoy and bipolar transistor, which sets the KS circuit Ul.

The disadvantage of this single-mode is low immunity. About

Closest to the invention is a single vibrator containing field and & 1Polar transistors, time specifying capacitor 2}.

A disadvantage of this device is its low noise immunity.

The purpose of the invention is to improve the noise immunity of the one-shot after the signal is generated during a certain time interval. 20

The goal is achieved by the fact that in a one-shot containing field-effect and bipolar transistors, the set time is a capacitor connected between the gate

field resistor and collector of a bipolar transistor, two resistors are introduced again, two forming diodes and a second capacitor, and the collector of the bipolar transistor is connected through the first resistor to the cathode of the first forming current and the second capacitor, which is connected to the second connected diode and the second resistor, and the anode of the first forming diode is connected to the drain of the field and bipolar transistors base.

The drawing shows a diagram of the one-shot.

Claims (2)

The single-oscillator consists of a field-effect transistor 1 and a bipolar transistor 2, the time of the driving capacitor 3, the charging resistor 4 of the load resistor 5, and also contains the first forming diode 6, the additional capacitor 7, the second forming diode 8, the coupling capacitor 9, the first resistor U , the second resistor 11. Capacitor 7, registers Yu and 11 together with oioc 8 form a circuit iie necessary to create a blocking voltage for diode 6, that it is impossible for the start-j pulse to pass through for a predetermined time after generating Ignala, Odoshno {brator works as follows. In the state before the arrival of the trigger pulse at the input, the transistors I and 2 are open. The capacitor 3 is charged before the voltage is close to the voltage supply. After the arrival of a negative triggering pulse, the input of the transistor 2 is closed and a positive voltage jump is transmitted from the collector circuit through the capacitor 3 to the transistor. Transistor 1 is closed, and capacitor 3 begins to recharge through resistor 4 before the time point, ps "and field-effect transistor I does not begin to conduct. A regenerative process occurs that opens both so-called transistors. At the moment of closing of transistor 2, the capacitor 7 through the resistor 10 and the diode 8 starts charging until the voltage is close to the power supply at equal time of the single vibrator and the peaicTopa Yu circuit of the capacitor 7. The voltage on the capacitor 7 blocks the diode 6, which makes it impossible passage triggering impulses. From the moment of termination of the regenerative process opening both transistors, the time defining capacitor 3 begins to discharge through resistor 10, transistor 2 and resistor 11 and at the moment of opening of diode 6 it becomes possible to restart the single-oscillator. The time during which the one-shot operation is not possible is determined by the constant time of the discharge circuit of the capacitor 9 and the use of isoftenes allows the use of a low-impact vibrator in automation systems, the signal of which activates the device of the system creating electrical transients in a transient mode and where it is repeated start of one-shot from them is not allowed. The use of the invention in this respect allows the rejection of special measures of noise protection, which can be difficult or require significant hardware costs. Claims. A single vibrator containing field and bipolar transistors, a time setting capacitor connected between the field gate and a bipolar transistor collector, characterized in that. that, in order to improve the noise immunity, two resistors were introduced into it, two forming diodes and a second capacitor, and the collector of the bipolar transistor is connected through the first resistor to the cathode of the first forming diode and the second capacitor, which is connected to the second diode and the second resistor connected, connected to the second resistor, The anode of the first forming diode is connected to the drain of the field and bipolar transistors. Sources: information taken into account in the examination 1. Goldeyberg L. M. Pulse and fr the devices, M., Sv z, 1973. 2.Goaling B. Application of field-effect transistors. M., Energie, 197O, p. iO4. °