RU1795491C - Alarm system - Google Patents

Abstract

The invention relates to devices for signaling the proximity of a person or object to a protected area and can be used to build automatic alarm systems. The aim of the invention is to simplify the device and increase its reliability. The device contains a sensing element 1, a generator 2, a limiter 3, a pulse shaper 4, executed on a D-trigger, two NAND elements 7, 8, time-setting elements 9, 12, a decoupling element 10, a storage element 11 When it appears near the sensitive element of the detection object, the oscillation frequency of the generator 2 decreases and the pulse duration approaching the input of the AND-NOT 7 element increases, which leads to an increase in the charge time of the drive 11 and a decrease in its discharge time, since the duration of zero In this case, the output of the AND-NOT 8 element decreases, which leads to an increase in the constant voltage on the drive 11, reaching the level of operation of the signaling unit 13 and detecting the object. 2 ill. ate with

Description

The invention relates to devices for signaling the proximity of a person or object to a protected area and can be used to build automatic alarm systems.

The purpose of the invention is to simplify the device and increase its reliability.

In FIG. 1 shows a diagram of a device; Fig. 2 is a timing chart illustrating its operation.

The device for alarming comprises a sensing element 1, a generator 2, a limiter 3, a pulse shaper 4, made on the D-trigger 5, the first and second logic elements I / 1-HE 7, 8, time-setting elements 9, 12, the connecting element 10, the storage element 11.

The sensitive element 1 is connected to the input of the generator 2, the output of the generator is connected to the input of the limiter 3, the output of which is connected to the input of the pulse former 4. The output of the pulse former 4 is connected to the first input of the AND-NOT 7 logic element and to the input of the standby multivibrator 6, the output of the logic element AND-NOT 7 is connected to the first input of the AND-NOT logical element 8. The output of the standby multivibrator 6 is connected to the second inputs of the AND-NOT 7, 8 logic elements. The output of the AND-NOT 8 logic element after time connected in series adayuschy element 9 and decoupling the conductive element 10 is connected to the input of the alarm unit 13. The first terminals of the storage member 11 and the driving time

element 12 are connected to the input of the signaling unit 13, and their second terminals are connected to the zero potential bus.

The device operates as follows.

In the absence of a detection object near the sensing element 1, the generator 2 generates oscillations (see Fig. 2a), which, passing through the limiter 3 (see Fig. 26) and the pulse shaper 4 (see Fig. 2c), are converted into rectangular pulses with a pulse duration equal to the pause duration. Upon transition from the state of logical zero to the state of the logical unit of the signal at the output of the pulse former 4, pulse formation by the multivibrator 6 begins (see Fig. 2d). The duration of the formed

multivibrator 6 in the standby mode of the pulse is selected longer than the duration of the pulse coming from the shaper 4. This leads to the appearance of

zero level at the output of the AND-NOT 8 logic element at moments of non-coincidence of pulses arriving at the first input of the AND-NOT 7 logic element with pulses arriving at its second input and second

input of the logical element AND-NOT 8 (see Fig. 2d). A storage voltage 11 is set to a constant voltage lower than the response voltage of the alarm unit 13 (see the left side of the timing diagram of FIG.

2g, the operating voltage is indicated by Vcp. indicated by a dotted line).

The decoupling element 10 eliminates the influence of a small output resistance of the AND-NOT 8 logic element on the processes

charge (through time, drive element 9) and discharge (after time, drive element 12) of drive 11, since at zero the outputs of the AND-NOT 8 logic element, the decoupling element 10 is closed.

when it appears near the sensitive element of the detection object, the generation frequency of the generator 2 decreases and the duration of the pulse arriving at the first input of the logical

element AND-NOT 7, which leads to an increase in the charge time of the drive 11 and a reduction in the time of its discharge, since the duration of the zero state of the output of the logical element AND-NOT 8

decreases, which will lead to an increase in the constant voltage on the drive 11, reaching its level of operation Ucp. alarm block 13 and object detection (see the right parts of time diagrams

FIG, 2) ..

For normal operation of the device, it is necessary that the time constant of the charge circuit of the drive 11 be greater than the time constant of the discharge circuit, which is achieved by a suitable choice of the timing of the driving elements 9 and 12.

The output resistance of the signaling unit 13 should be much greater than the time resistance of the driver 12,

to exclude its influence on the processes of charge-discharge of the storage ring, or its value should be taken into account when choosing the ratio of the resistance of the time of the driving elements 9, 12.

Claims (1)

SUMMARY OF THE INVENTION An alarm device comprising a sensor, the output of which is connected to an input of a generator, the output of which is connected to an input of a limiter, a pulse shaper and an alarm unit, characterized in that, in order to simplify the device and increase the reliability of the device, it is introduced two AND-NOT elements, a waiting multivibrator, two timing elements, a decoupling element and a storage element; the output of the limiter is connected to the input of the Pulse driver, the output of which is connected to the input of the first AND-NOT element and to the input of the standby multivibrator, the output of the first AND-NOT element is connected to the first input of the second AND-NOT element, the output of which is connected in series after the first time the element that decouples the element is to the input of the signaling unit, the first conclusions of the storage element are connected to the input of the signaling unit, and the second conclusions are combined and connected to the zero potential bus, the output of the multivibrator waiting for It is connected to the second inputs of the first and second elements AND NOT. U At V and B w) L L