SU1117672A1 - Capacitive-type alarm system - Google Patents

Abstract

A DEVICE FOR ALARM SIGNALING A CAPACITY TYPE, containing a differential transformer, the output of which is connected to the first input of the time selector through the serially connected high-frequency amplifier, detector, modulator, frequency analyzer and direct current amplifier the first output of the device, the generator / high frequency, the output of which is connected to the first input of the differential transformer and through a rectifier connected The second input of the time selector, two capacitive antennas, characterized in that, in order to improve the accuracy of the device, two current meters, a reference element and two elements And are entered, the first capacitive antenna is connected to the input of the first current meter, the output of which is connected to the second input of the differential transformer, the second output of the current meter is connected to the first input of the comparison element, the first output of which is connected to the first, input of the first element I, the output of which is the second output of the device The second capacitive antenna is connected to the input of the second current meter, the first output of which is connected to the third input of the differential transformer, the second output of the current meter is connected to the second input of the comparison element, the second output of which is connected to the first input of the second element And whose output is the third output of the device the output of the executive unit is connected to the second inputs of the first and second elements I.

Description

The invention relates to technical means of protection and can be used for alarming, and for protecting the perimeters of objects that have ftx. important: A device for capacitive-type alarm is known, comprising antennas, a generator, a signal processing and signal-generating unit Alarm 1. The closest to the invention in its technical essence is a capacitive type alarm device containing a differential transformer, the output of which is connected to the first time selector input through a series connected high frequency amplifier, detector, modulator, frequency analyzer and DC amplifier. the output of which is connected to the input of the execution unit, the output of which is the first output of the device, a high frequency generator, the output of which is connected to the first input g The differential transformer and through the expander is connected to the second input of the time selector, two capacitive antennas. However, the known devices have low accuracy. . The aim of the invention is to improve the accuracy of the device. This goal is achieved in that a capacitive-type alarm device containing a differential transformer whose output is connected via a serially connected high-frequency amplifier, detector, modulator, frequency analyzer and direct-current amplifier to the first time selector input, the output of which is connected to the input an execution unit, the top of which is the first output of the ycT relay, a high-frequency generator whose output is connected to the first input of the differential transformer ora and through a rectifier connected to the second input of the time selector, two capacitive antennas, two current meters, a reference element and two elements And, the first capacitive antenna is connected to the input of the first current meter, the output of which is connected to the second input of the differential transformer, the second output of the meter current is connected to the first input of the reference element, the first output of which is connected to the first input of the first element I, the output of which is the second output of the device, the second capacitive antenna connected to the input at the second current meter, the first output of which is connected to the third input of the differential transformer, the second output of the current meter is connected R to the second input of the comparison element whose second output is connected to the first input of the second element I, the output of which is the third output of the device, the output of the execution unit is connected to the second inputs of the first and second elements I. The drawing shows the functional diagram of the proposed device. The device contains capacitive antennas 1 and 2, current 3 and 4 meters, differential transformer 5, high frequency generator 6, rectifier 7, high frequency amplifier 8, detector 9, modulator 10, frequency analyzer 11, DC amplifier 12, time the selector 13, the executive unit 14, the element 15 of the comparison and the elements And 16 and 17 .. The device operates as follows. When an intruder approaches an antenna, for example 1, its capacity increases. The magnitude of the current flowing through the circuit consisting of half of the primary winding of the differential transformer 5, the current meter and the antenna 1, increases. At the output of the differential transformer 5, a signal appears that is amplified by amplifier 8 and detected by detector 9. Unipolar pulses from the output of detector 9 are sent to modulator 10, where an envelope is allocated, whose frequency depends on the amplitude change of unipolar pulses, depending in turn, on the nature of the change in antenna capacity. The output signal from the modulator 10 is fed to a frequency analyzer 11, which may be a band-pass filter. The frequency analyzer 11 only transmits signals whose frequency is close to the frequency of the capacitance of the antenna 1 when the person approaches it. The filtered signals are amplified by the DC amplifier 12 and fed to the first input of the time selector 13. The second input of the time selector 13 receives a constant level signal through the rectifier 7 from the high-frequency generator 6. In the absence of a signal from the analyzer 11 of the frequency, the time selector 13 transmits a constant level signal to the executive unit 14, which can be executed from a series-connected trigger and relay.

The time selector 13 may consist, for example, of a series-connected integrator and a two-adder adder, the second input of the adder being connected to the output of rectifier 7. The output signal of the adder is the difference of the signals of the miter 7 and the integrator which is connected by its input to 12 amp DC output

If the signal at the output of the amplifier 1 DC exists for a sufficiently long time, which indicates, for example, an attempt to overcome the protected perimeter in the area of any capacitive antenna 1 or 2 (in this case capacitive antenna 1), then the signal at the integrator's output increases to such a level that the output signal of the adder is reduced to a level that ensures the trigger switch of the execution unit 14 to the idle state. As a result, an alarm signal is generated that has a general character, since this signal is generated when the capacitance of any of the capacitive antennas 1 or 2 changes. This signal is generated when the generator 6 is out of service, as well as when the power supply that supplies the entire device is turned off, the alarm is generated. in the latter case it is possible because This signal arises when current passes through the normally closed contacts of the output relay, with a third-party source that belongs to the equipment that receives the Alarm signal.

Comparison element 15 may be executed from a series-connected balanced amplifier with two inputs, a trigger and an inverter.

The inputs of the balanced amplifier are connected to the meter 3 and 4 current, and the trigger output is connected to one of the AND 16 and 17 elements, for example, the AND 16 element, directly, and to the other (in this case, the And 17 element) via an inverter.

If the capacitances of both capacitive antennas 1 and 2 are equal, then the signals from the outputs of the 3 and 4 current meters are also equal. In this case, the signal at the output of the balanced amplifier of the comparison element 15 is zero and the trigger of the comparison element 15 is in the off state, i.e. there is no signal at its output. Consequently, the input element And 16 signal is missing. As the capacitance of the capacitive antenna 1 only increases, the signal from the current meter 3 increases, and the signal from the current meter 4 remains unchanged. At the output of a balanced amplifier, a signal of a defined polarity arises from element 15 of the comparison, which, when a certain level is reached, switches the trigger of element 15, a comparison. The resulting signal at the output of the trigger of the comparison element 15 is fed to the input of the element And 16. If the capacitance of the capacitive antenna 1 increases so that the execution unit 14 is triggered and generates a general alarm signal, then the element 16 also generates a signal indicating that The perimeter section where capacitive antenna 1 is located. If there is a change in the capacitance of capacitive antenna 2, then an increase in the signal from the output of the current meter 4 causes a balanced amplifier element 15 of the comparison signal to appear at the output and the opposite, in comparison with the case considered, elements AND 16 and 17 will remain in the initial state. Then, when generating a general alarm, the executive unit 14 triggers element I 17 and indicates that an attempt to violate the perimeter was recorded in the area covered by the capacitive antenna 2.

The positive effect of using the invention is due to its technical features.

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Claims (1)

A CAPACITIVE ALARM DEVICE containing a differential transformer whose output is connected through a series-connected high-frequency amplifier, a detector, a modulator, a frequency analyzer and a DC amplifier to the first input of a temporary selector, the output of which is connected to the input of the executive unit, the output of which is the first output device, high-frequency generator, the output of which is connected to the first input of the differential transformer and is connected to the second the input of the temporary selector, two capacitive antennas, which is distinguished by the fact that, in order to increase the accuracy of the device, two current meters, a comparison element and two AND elements are introduced into it. The first capacitive antenna is connected to the input of the first current meter the output of which is connected to the second input of the differential transformer, the second output of the current meter is connected to the first input of the comparison element, the first output of which is connected to the first, the input of the first element And, the output of which is the second output of the device, the second capacitor a fixed antenna is connected ^ to the input of the second current meter, the first output of which is connected to the third input of the differential transformer, the second output of the current meter is connected to the second input of the comparison element, the second output of which is connected to the first input of the second element And, the output of which is the third output of the device, the output of the Executive unit is connected to the second inputs of the first and second elements I. . SLL ·, 1117672