RU206374U1 - IMPULSE FORMER - Google Patents

Abstract

The claimed technical solution relates to impulse technology and can be used in automation systems requiring accuracy, stability, reliability, minimum dimensions and weight, for example, in spacecraft. The technical result consists in providing the possibility of forming subsequent pulses, in increasing the utilization factor of the capacitance of the timing capacitor, in increasing the stability and accuracy of the generated pulses in conditions of temperature spread, in reducing the current consumption from the power source, in reducing the mass and dimensions of the device, in increasing reliability by simplifying electrical circuit. For this, a pulse shaper is proposed containing an RS-flip-flop, the direct output of which is connected to the input of the threshold element with the NOT function through a timing resistor and a capacitor, a NAND logic element, the first input of which is connected to the output of the threshold element with the NOT function and through an inverter NOT with setting input RS-flip-flop.

Description

The claimed technical solution relates to the field of automation, impulse technology and can be used in devices with high accuracy requirements in conditions of temperature spread, as well as increased reliability, for example, in spacecraft.

From the prior art, a pulse shaper is known from the description of the invention to copyright certificate No. 483779, N03K 5/01, 12.12.75. The device contains a bus of input signals, a trigger on integrated circuits, an inverter, two transistors, three resistors, a capacitor, and two diodes. The front of the output pulse is formed by a change in the initial state of the trigger, while the timing capacitor is charged through the duration control transistor operating in a linear mode. At the end of the charge, the trigger switches to its original state and a drop in the output pulse is formed at its inverse output. Disadvantages: the linear mode of the transistor is unstable under conditions of wide temperature spread and the pulse duration will have an error. The device draws current in its initial state from the power supply. Unlike the claimed device, the electrical circuit contains more elements and, therefore, less reliability.

The closest in technical essence is a pulse shaper known from the description of the invention to copyright certificate No. 718899, Н03К 3/335, 28.02.80, which is selected as a prototype. The known device consists of a thyristor, three capacitors (one of them is a timing one), an output transistor connected according to a common emitter circuit, an OR-NOT logic element with an RS-trigger function, a power bus, an input bus, a bias bus, and resistors. In the initial state, the transistor is open, the thyristor is off, and the timing capacitor is charged. The front of the output pulse is formed by turning on the thyristor, which connects the base of the transistor to the bias bus and turns it off. The charged timing capacitor is discharged through the open thyristor, thus forming a flat top of the output pulse. After the capacitor is discharged, the thyristor turns off, since the current through the anode resistor goes additionally to the base of the transistor and does not provide the holding current. The timing capacitor is charged through the anode resistor to the bias voltage plus the voltage at the base-emitter junction of the transistor. The transistor opens and forms the falloff of the output pulse. Disadvantages: the level of the voltage that turns on the transistor has a voltage component at the base-emitter junction of the transistor, which is unstable under conditions of wide temperature variation. The pulse duration will also depend on the temperature.

The known device in the absence of input pulses consumes current from the power source. Unlike the claimed device, the electrical circuit of the prototype has twice the number of elements and, as a result, has less reliability.

Common features of the prototype and the claimed device. Timing RC circuits (capacitor and resistor). Operation mode switches such as triggers. Resetting occurs during the decay of the output pulse. The ability to divide the frequency of the input pulses.

The task of the utility model is to increase the stability and accuracy of the generated pulses under conditions of a large temperature spread. Increasing the utilization factor of the capacity of the timing capacitor. Reduction of the consumed current. Improving reliability by simplifying electrical wiring.

To achieve the set task, a shaper is proposed that contains: an RS-trigger, a threshold element with a NOT function, an NAND gate, a NOT inverter, a timing resistor and a capacitor. The direct output of the RS-flip-flop is connected through a series circuit of the timing resistor and capacitor to the minus of the power supply, and the point of their connection to the input of the threshold element with the NOT function, the output of which is connected to the second input of the AND-NOT logic element and through the NOT inverter with the RS- setting input trigger, the inverse output of the RS flip-flop is connected to the first input of the AND-NOT element, at the output of which a pulse is generated.

In the drawing, FIG. 1 shows a schematic diagram of the proposed device.

Input S of the RS-flip-flop 1 is connected to the negative of the power supply, the information input D is connected to the positive of the power supply, the bus 7 of the input pulse is connected to the input C, the direct output to the first terminal of the resistor 2, the inverse output to the first input of the NAND logic element 6. The capacitor 3 is connected by the first terminal to the second terminal of the resistor 2 and to the input of the threshold element 4 with the NOT function, the second terminal of the capacitor 3 with a negative supply. The output of the threshold element 4 with the function NOT is connected to the second input of the logic element 6 and to the input of the inverter 5, the output of which is connected to the setting input R of the RS flip-flop 1.

The output bus of the device is connected to the inverse output of logic element 6.

The device works as follows.

Initial state:

at the direct output of the RS-flip-flop 1 - zero level (hereinafter “zero”);

at the inverse output of the RS-flip-flop 1, the supply voltage (hereinafter "unit");

capacitor 3 - discharged;

at the output of the threshold element 4 with the function NOT - "one";

at the output of the inverter 5 - "zero";

at the output of logic element 6 - "zero".

When a voltage drop from "zero" to "one" appears at input C of the RS-flip-flop 1, trigger 1 switches to "one" at the direct output.

The charge of the capacitor 3 begins. At the inverse output of the RS-flip-flop 1, “zero” appears. At the output of the logical element 6, the front and the beginning of the output pulse are formed. At the end of the charge of the capacitor 3, the threshold element 4 with the function NOT switches to "zero" at the output and then through the inverter 5 RS-flip-flop 1 is set to its original state. The discharge of the capacitor 3 begins through the direct output of the RS-flip-flop 1, while the formation of the pulse from the output of the logic element 6 continues. At the end of the discharge of the capacitor 3, the threshold element 4 with the function NOT switches to "one" at the output and "ones" are set at both inputs of the logical element 6, and the output pulse decays at the output. This completes the pulse shaping process. The shaping of the output pulse ends in the initial state and the device does not need to be ready for re-shaping. For the duration of the pulse formation, the input C of the trigger is locked, which means that the device can operate in the frequency division mode and has noise immunity. In the prototype shaper, the output pulse is generated during the discharge of the timing capacitor.

In the claimed shaper, the duration of the generated pulses is determined by the total charge and discharge time of the timing capacitor with the completion of the pulse formation cycle in the discharged state, which increases the capacity utilization factor. Since the loads of the circuit elements are high-impedance inputs of other elements, the consumption from a single power source goes only to charge the timing capacitor. This sets light modes for the elements and, taking into account the simplification of the circuit, ensures the efficiency and reliability of the device for long-term operation. In the initial state, the driver practically does not consume current (fractions of a microampere).

The technical result consists in increasing the stability and accuracy of the generated pulses in conditions of temperature spread. In increasing the utilization factor of the capacity of the timing capacitor. Reducing the current consumption from the power source. Improving reliability by simplifying electrical circuits.

Threshold element 4 with the NOT function has two switching thresholds - on the front of the input signal and on the falling edge.

When charging and discharging the capacitor 3, the thresholds cut off the sections with the greatest curvature from the exponentials, which makes it possible to significantly increase the stability and accuracy of the formation of the output pulse duration.

FIG. 2 shows the diagram of the charge and discharge of the capacitor and the diagram of the output pulse. The end of the charge and discharge of the capacitor is shown with a dotted line.

The claimed pulse shaper is implemented on microcircuits, the discrete components of which are manufactured on a single semiconductor single crystal. In this regard, the temperature and time changes in the parameters of individual components are the same. Practical application confirms the sufficiently high stability of the thresholds for switching on - switching off the threshold element 4 with the NOT function when exponential signals are applied to its input.

The shaper prototype was assembled on six elements.

Of the patent information materials known to the applicant, no features similar to the set of features of the claimed object have been found.

Claims (1)

A pulse generator containing a timing resistor and a capacitor, an RS flip-flop, characterized in that a threshold element with the NOT function, an AND-NOT logic element, a NOT inverter are introduced, while the direct output of the RS flip-flop is connected through a series circuit of the timing resistor and capacitor to the minus power supply, and the point of their connection - to the input of the threshold element with the NOT function, the output of which is connected to the second input of the AND-NOT logic element and through the NOT inverter to the setting input of the RS-flip-flop; the inverse output of the RS-flip-flop is connected to the first input of the AND-NOT element, at the output of which a pulse is generated.

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