JPH0116233Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a security device that utilizes the Doppler effect of ultrasonic waves.

2. Description of the Related Art Security devices that utilize the Doppler effect of ultrasound have been known as security devices that detect illegal intruders. This security device usually consists of a detector installed in each monitoring area and a receiver that centrally controls the operation of each detector.An example of the above detector is explained with reference to FIG. As a result, ultrasonic waves are emitted from the transmitting transducer 2 to the monitoring area, and the reflected waves thereof are received by the receiving transducer 3. When there is no intruder within the monitoring area, the ultrasonic waves are not amplitude modulated, and therefore the reflected waves received by the receiving transducer 3 are only high frequencies, so they are passed through the high frequency amplifier 4 to the detector 5. Even if the wave is detected at , its output is not detected. However, when an intruder exists within the monitoring area, the ultrasonic wave is disturbed by its operation, amplitude modulated, and received by the wave receiving transducer 3. Therefore, the output passes through a high frequency amplifier 4, and the modulated wave is detected by a wave detector 5. An abnormal component caused by the intruder, that is, a low frequency component of 200 Hz or less is detected, and it is supplied to a low frequency amplifier 6 and amplified. The signal is then converted to DC by a DC converter 7 and sent to the receiver, and the output lights up a lamp on a display 8.

The detectors configured as described above are provided for each monitoring area, so if you do not keep it in place once it is activated, you will not know in which monitoring area the detector has activated, so the display 8 The lamp remains lit.

By the way, when performing an operation test of such a detector, since the above-mentioned transmitting and receiving transducers 2 and 3 have wide directivity, it is necessary to test whether or not they operate at multiple locations within the monitoring area when a tester is present. must be tested. However, during such tests, if the display 8 is kept lit as during monitoring, the display 8 will remain lit each time a test is performed at each location in the monitoring area, and each time the receiver There is an inconvenience in that the power supply to the detector must be cut off on the side to restore the above-mentioned lighting maintenance. The ultrasonic waves radiated into the monitoring area may also be activated, for example, by wind vibrations caused by air conditioning. Therefore, in the operation test, if the test result was determined only by the lighting of the indicator 8, it would be difficult to distinguish whether it was caused by the tester's actions or the wind sway as described above. Therefore, accurate operation tests cannot be performed.

Therefore, during the above test, we installed a device that would prevent the indicator from remaining lit even if the detector was activated and the indicator would light up, and also allow connection of a measuring device that measures analog changes in low frequency components. Proposed. To explain this with reference to FIG. 2, first, the display 8 in FIG. 1 is provided with means for releasing the lighting state. That is, the light emitting diode LED connected through the collector-emitter of the transistor Q whose base is connected to the output side of the DC converter 7 is also connected through the thyristor SCR whose gate is connected to the output side of the DC converter 7. A light-emitting diode LED lighting holding circuit is configured, and a test switch that is opened during the above test is connected during this lighting holding circuit.
TS is connected. Further, on the output side of the low frequency amplifier 6, an output terminal is connected to a measuring device 9 for measuring analog changes in low frequency components during the above test.
TE is provided.

During monitoring, when an intruder is present in the monitoring area and a low frequency component is detected by the wave detector 5, it is sent to the receiver via the low frequency amplifier 6 and the DC converter 7, and is also sent to the display 8. is applied, transistor Q becomes conductive, and the light emitting diode
The LED lights up, and at the same time, the thyristor SCR is fired and conductive, and the light emitting diode LED is kept lit through the thyristor SCR and the test switch TS.

When performing an operation test, first open the test switch TS to open the lighting holding circuit of the light emitting diode LED, and then measure the analog change in the low frequency component at the terminal TE with a measuring device such as an oscilloscope or AC voltmeter. Connect.
When a tester enters the monitoring area, the detector 5 detects a low frequency component of 200 Hz or less due to the same operation as when an intruder is present as described above, and further amplifies and converts it to DC. The light is sent to the receiver and applied to the display 8, causing the transistor Q to conduct and lighting up the light emitting diode LED. However, since the thyristor SCR is not fired, the lighting of the light emitting diode LED is not maintained, and the light emitting diode LED is not kept lit. Each time the tester moves to each location within the same area, the light emitting diode LED lights up, and on the other hand, low frequency components are detected by the measuring device 9 connected to the terminal TE according to the tester's movements. Analog changes of the light emitting diode LED above are displayed
It is confirmed that the lighting is due to the action of the examiner. Moreover, this measuring device 9 allows to know the environmental changes caused by the above-mentioned wind sway in the monitoring area, and the sensitivity can be adjusted accordingly.

However, according to such a configuration, the opening of the light-emitting diode LED lighting holding circuit during testing,
The connection of the measuring instrument 9 to the low frequency amplifier 6 is not only cumbersome because it is done separately by operating the test switch TS and connecting to the output terminal TE, but also if the measuring instrument 9 is connected to the output terminal TE. If you forget to open the test switch TS after connecting it,
Since the light emitting diode LED remains lit, if the tester does not notice this, there is a risk that the test results at each location may be mistaken as normal.
Note that the test switch TS must be returned to its original state by closing the contacts after the test is completed, but if you forget to do so, you will not be able to tell in which monitoring area the detector was activated. There is a risk.

Therefore, the present invention eliminates the above-mentioned drawbacks by connecting the measuring instrument 9 using a plug P and a jack J, and replacing the normally closed contact of the jack J with a test switch TS. An example of this will be explained with reference to FIG. 3. A jack J is provided on the output side of the low frequency amplifier 6 in FIG. ing.

Since the present invention is constructed as described above, simply by inserting the plug P into the jack J, the lighting holding circuit of the light emitting diode LED is opened and the measuring instrument 9 is connected to the low frequency amplifier 6 at the same time. The above test can be performed more easily.

As described above, according to the present invention, the opening of the lighting holding circuit of the light emitting diode LED during the test,
The measuring instrument 9 can be connected to the low frequency amplifier 6 at the same time by inserting the plug P into the jack J, so operation is easy and the test switch can be easily connected.
This has excellent effects such as eliminating inconveniences that would occur if the TS was not opened, or even if the contacts were not closed and returned to their original state after the test was completed.

[Brief explanation of the drawing]

Fig. 1 is a block diagram explaining a detector of a security device using the Doppler effect, Fig. 2 is a block diagram showing a conventional security device of this type, and Fig. 3 is a block diagram showing an embodiment of the present invention. It is. 1... Transmitter, 2... Transmitting transducer, 3... Receiving transducer, 5... Detector, 8... Display, 9... Measuring device, LED... Light emitting diode, Q... Transistor , SCR...Thyristor, P...Plug,
J... Jack.

Claims (1)

[Scope of utility model registration request] A device that emits ultrasonic waves to a monitoring area, a device that receives reflected waves of the ultrasonic waves, and a low frequency component generated by the Doppler effect due to the movement of an intruder existing in the monitoring area from the reflected waves. a device for detecting the low frequency component, a display device that is turned on and held lit by the detection of the low frequency component, a means for opening a lighting holding circuit of the display device during a test, and a device that detects the low frequency component. A crime prevention device comprising a means for connecting a measuring device for measuring an analog change in a low frequency component detected by the device, wherein the means for connecting the measuring device to the device for detecting a low frequency component comprises a pair of plug and jack. A crime prevention device comprising: a normally closed contact of the jack as a means for opening a lighting holding circuit of an indicator.