JPH02167436A - Seismoscope - Google Patents

Abstract

PURPOSE:To obtain the output of the seismoscope corresponding to the magnitude of an earthquake at all times by providing an acceleration sensor, a rectifier, and a comparator. CONSTITUTION:This seismoscope is provided with the acceleration sensor 14 which generates an output voltage corresponding to the vibration acceleration of an earthquake, a shock, etc., the rectifier 15 which rectifies the output of the sensor 14, and the comparator 16 which compares the output voltage of the rectifier 15 with a reference voltage. Further, an adjusting terminal 18 for adjusting the reference voltage of the comparator 16 is provided. Then the output of the sensor 14 corresponds to the level of the earthquake wave and is rectified 15 and the momentary intensity of the earthquake wave is reflected in a high-low output voltage signal obtained through the comparator 16. Therefore, a stable output signal with reproducibility is obtained from any earthquake wave and the halfway process of this signal is used as a judgement material to decide the intensity of the earthquake and discriminates between the earthquake and shock.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to a seismic sensor for sensing earthquakes, and in particular, it is an object to provide a seismic sensor that generates a stable output signal.

2. Prior Art As shown in FIG. 3, a first example of a conventional seismic sensor of this type includes a steel ball 2 placed in a central recess of a container 1, which can be moved up and down above the steel ball 2. A movable contact 4 is pressed against the top of the slide pin 3, and a lead wire 6 is connected to the movable contact 4 and the fixed contact 5, respectively.
．． 7 is connected, and when a vibration impact force of more than a certain value is applied, such as during an earthquake, the steel ball 2 pops out from the recess of the container L, pushes the slide pin 3 upward, and connects the movable contact 4 and the fixed contact 5.
The circuit was closed and the on/off signal of the contact point as an earthquake signal was taken out from the lead wire 6.7.

As shown in FIG. 4, a second example of a conventional seismic sensor of this type is that mercury 9 is sealed in the central recess of a metal container 8, and the mercury 9 is surrounded by metal container 8 and glass. An electrically insulated electrode 11 is provided at 10, and lead wires 12 and 13 are connected to the metal container 8 and the electrode 11, respectively. The mercury 9 pops out from the recess of the metal container 8 and the metal container 8
The mercury 9 itself serves as a contact point to close the circuit between the electrode 11 and the mercury 9, and the on/off signal of the contact point as an earthquake signal is taken out from the lead wire 12.13.

Problems to be Solved by the Invention In the second example of the conventional mercury type, the mercury itself serves as the contact point, so the structure is simple and can be made smaller. What is common is that in such a structure, the response of the on/off signal of the seismic sensor to seismic waves does not necessarily match the magnitude of the seismic waves, as shown in Figure 5, and as shown in (a) of (b). As a result of the delayed response, the on-signal may deviate, or as shown in (b), the on-signal may be generated due to the inertia even though the seismic waves have become smaller.

If this kind of phenomenon occurs in a seismic sensor, it will not have much effect when used in a seismic device that judges the intensity of an earthquake based on the first ON signal alone, but if it is・
When used in a seismic device that attempts to distinguish between an earthquake and a shock by looking at the progress of an OFF signal (for example, when activated when there is a certain number of pulses with an ON signal of a certain pulse width or more), This became a major issue, and in some cases there was a risk that the system would work in a small earthquake but not in a large earthquake.

The present invention is intended to solve such conventional problems, and aims to make it possible to always obtain an output from a seismic sensor that corresponds to the magnitude of seismic waves.

Means for Solving the Problems In order to solve the above problems, the seismic sensor of the present invention includes an acceleration sensor that generates an output voltage corresponding to vibration acceleration, a rectifier that rectifies the output of the acceleration sensor, and an output voltage of the rectifier. and a comparator that compares the voltage with a reference voltage and generates an output voltage signal of "H" or "L'".

Effect of the present invention With the above-described configuration, the output from the acceleration sensor can always be an output corresponding to the strength of the seismic wave, so it is rectified and the “°H°
The output voltage signal of "Par L" reflects the instantaneous strength of the seismic waves, and unlike conventional seismic sensors, there is no large delay in operation or output of signals due to inertia. Able to output stable output signals with reproducibility.

Embodiments Hereinafter, embodiments of the present invention will be described based on the accompanying drawings.

In FIG. 1, reference numeral 14 is an acceleration sensor that generates an output voltage according to vibration acceleration during an earthquake or impact, 15 is a rectifier that rectifies the output of the acceleration sensor I4, and 16 is a reference voltage that compares the output voltage of the rectifier. When the reference voltage is exceeded, “+”
It is a comparator that outputs an output voltage signal of "L" to the output terminal 17 when the voltage is HI+ or lower than the reference voltage. Note that 18 is an adjustment terminal for adjusting the reference voltage of the comparator 16.

Figure 2 shows the operation of the seismic sensor with the above configuration during an earthquake. ), and when this is input to the comparator, only the part that exceeds the reference voltage of the comparator becomes "H", and the other parts become "L", resulting in an output signal like (d). This output signal almost accurately reflects the instantaneous intensity of the seismic wave, and is not affected by inertia etc. like the output signal of a conventional seismic sensor. H"
・By counting the time width of “°L'' and the number of pulses within a specified time, it becomes possible to judge the strength of an earthquake with good reproducibility and even distinguish between a shock and an earthquake. In order to adjust the sensitivity of the earthquake sensor to the strength of an earthquake, it was necessary to change the shape of the recess in the container, the size of the steel ball, the weight of the mercury, etc., which was not easy to do. According to the vibration sensor of this embodiment, adjustment can be easily performed using the adjustment terminal 18 shown in FIG.

Although the comparator is described as having no hysteresis in FIGS. 2C and 2D, in reality, hysteresis is provided to ensure stable operation.

Effects of the Invention As described above, the sensitivity device of the present invention provides the following effects.

The output from the acceleration sensor is an output corresponding to the strength of the seismic wave, which is rectified and passed through a comparator to obtain "'H".
・Since the output voltage signal of “L” reflects the instantaneous strength of the seismic wave, it is possible to output a stable output signal that is reproducible for any seismic wave, and the progress of this signal Using this as a basis for judgment, it will be possible to judge the strength of an earthquake and to distinguish between an earthquake and a shock.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a seismic sensor according to an embodiment of the present invention, Fig. 2 is an explanatory diagram of the operation of the seismic sensor, Figs. 3 and 4 are constituent countries of a conventional seismic sensor, and Fig. 5 is an explanatory diagram of the operation of the seismic sensor. 14... Acceleration sensor, 15... Rectifier, 16... Comparator.

Claims (1)

[Claims] A seismic sensor comprising an acceleration sensor that generates an output voltage according to vibration acceleration, a rectifier that rectifies the output of the acceleration sensor, and a comparator that compares the output voltage of the rectifier with a reference voltage and generates an output voltage signal. vessel.