JPH0452403B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a portable electronic water depth gauge, and more particularly to a portable electronic water depth gauge in which a water depth sensor composed of a pressure sensor that converts pressure into an electrical signal is incorporated into, for example, an underwater watch. This relates to electronic depth gauges.

[Prior Art] For example, mechanical depth gauges that measure pressure, which is one type of underwater environment, and display water depth, have conventionally been used. The principle is to balance pressure with the repulsive force of an elastic body, mechanically expand the position of balance, and display the amount as water depth.

On the other hand, recently, with the advent of semiconductor-type pressure sensors and the like, there has been remarkable progress in pressure sensors that can obtain electrical output. For this reason, such pressure sensors first came to be used in industrial pressure gauges, automobiles, etc., and significant improvements have been seen not only in accuracy and durability but also in terms of miniaturization. Therefore, attempts and developments are currently underway to apply this as a pressure sensor for portable electronic depth gauges.

[Problems to be Solved by the Invention] Among the portable electronic depth gauges and water depth gauges mentioned above, mechanical depth gauges have large errors due to aging of the elastic body and expansion mechanism, and are susceptible to impact. Errors also occur due to factors such as temperature, magnetism, etc.
Therefore, mechanical depth gauges needed to be adjusted each time they were used. As described above, it is difficult to use and has poor accuracy, so the reality is that water depth is not used much, even though water depth is vital information for those carrying it.

Next, although the new type of pressure sensor mentioned above has made great progress in terms of performance and miniaturization, if we try to apply it to portable electronic depth gauges, etc. It is necessary to take measures to prevent the atmospheric environment and conditions, such as voltage and changes over time, from affecting the underwater depth display. this is,
For example, this problem is related to where to set the initial value of the water depth display, and in other words, it is a problem that requires accuracy in the start time of measuring the water depth value. moreover,
Since portable devices are powered by batteries, it was necessary to find ways to keep the average current consumption as low as possible.

The present invention was made in order to solve the above-mentioned problems, and in addition to being highly accurate and reliable and capable of long-term use, the present invention is a highly automatic mobile device that is easy to use and does not require any trouble. The purpose of this invention is to provide an electronic depth gauge for use in water.

[Means for Solving the Problems] A portable electronic water depth gauge according to the present invention includes a structure in which two side surfaces of an insulating substrate having a sharp edge angle formed by two side surfaces are separated at the center of the edge angle. It consists of a power supply electrode and a detection electrode arranged at A water sensor that takes out the potential of the detection electrode that occurs when the entire electrode is immersed in water as an output signal, a pressure sensor that outputs a pressure signal depending on the water depth, and a pressure sensor that is connected to the pressure sensor and receives the signal from the water sensor. a detection circuit that automatically enters an operating state and performs a detection operation intermittently in synchronization with a signal from a timekeeping circuit; a decoder means that outputs a signal from the detection circuit as a water depth value signal;
and a memory circuit that stores a water depth value signal at the time of initial entry into the water as a reference value, and the decoder means has a function of outputting a value obtained by subtracting the reference value of the memory circuit from the measured water depth value as a water depth value signal for display to the display driving means. It is equipped with the following.

[Function] In the present invention, first, a water sensor is provided in which a power supply electrode and a detection electrode are formed on an insulating material base having the above-mentioned ridge angle, and are arranged separately around a sharp ridge angle formed by two sides. In order to use the water sensor, attach this water sensor to the outside of the case of the portable electronic water depth meter, and by providing a detection resistor between the detection electrode and V _SS , it will be connected to the power supply electrode and detection at the time of initial entry into the water. For example, when the electrode is connected with seawater, a current is obtained due to the electrical conductivity (resistance) of the seawater.
As this flows through the detection resistor, a voltage is generated across the detection resistor, so water entry is confirmed by the voltage rise of the detection electrode, and from this point on, the pressure sensor is automatically activated to measure the water depth. You will be able to do it. In addition, when the entire body separates from water, since the insulator base is formed at a ridge between the two electrodes, the water adhering between the two electrodes can be quickly and completely cut off, and the voltage across the detection resistor is no longer generated. At this point, water depth measurement is automatically stopped.

In addition, the decoder means can convert the signal from the storage circuit into a signal suitable for display and at the same time subtract the reference value of the storage circuit from the measured water depth, so that accurate water depth values can be used for display. [Embodiment] Fig. 1 is a block diagram showing an example of the configuration of a portable electronic depth gauge according to the present invention for detecting water depth. In the figure, 1 is a water depth sensor consisting of a pressure sensor that converts pressure into an electrical signal, 2 is a detection circuit that amplifies and detects the electrical signal output from this water depth sensor, 3 is a decoder that converts it into a signal suitable for display, and 4 1 is a memory circuit, 5 is a display drive circuit, 6 is a display device, 7 is a water sensor that determines whether the device has entered water, 8 is a control circuit, 9 is a timing circuit, 1
0 is a waveform shaping driver. The decoder 3 also has the role of subtracting the reference value in the memory circuit 4 from the measured water depth value output by the water depth sensor 1 and outputting it to the display drive circuit 5 as a display water depth value signal.

In such a configuration, when the portable electronic depth gauge reaches the water, the water sensor 7 outputs a voltage, which is shaped into a waveform by the driver 10 and operates the control circuit 8. The control circuit 8 sends out intermittent pulses in synchronization with the clock signal of the timer circuit 9, and operates the detection circuit 2, decoder 3, and display drive circuit 5 intermittently. The memory circuit 4 includes a first
The detected value of the water depth sensor for the second time, that is, the value at the water surface is stored, and the decoder 3 subtracts the stored value from the detected value for the second and subsequent times, converts it into a signal suitable for display, and sends the display drive circuit 5. The display device 6 is driven through the display device 6.

Therefore, measurements are always made based on the water surface pressure, allowing accurate water depth to be displayed, and since it operates intermittently, power consumption can be reduced.

FIG. 2 is a perspective view showing an embodiment of the structure of an electrical conductivity sensor type water sensor used in a portable electronic depth gauge according to the present invention. In the figure, 11 is a prismatic insulating substrate with an acute edge and an isosceles triangular cross section, 12 is a power supply electrode provided on one side forming the edge of the insulating substrate 11, and 13 is the other side. A detection electrode 14 provided at the detection electrode 14 is a pull-down resistor connected to the detection electrode 13 to detect a change in potential.

In the figure, normally the potential of the OUT terminal is at the voltage level on the V _SS side due to the pull-down resistor 14 used as a detection resistor, but when the sensor is submerged in water, the electrical conductivity between both electrodes increases. However, since the potential changes to the V _DD side, it can be detected that it has reached the water. The reason why the shape is convex is to prevent malfunctions due to water droplets, etc. Even if water droplets adhere, the surface tension of the water is broken by the sharp convex part formed by the ridge, so the sensor will not operate properly. It can only be activated when submerged in water.

In the above embodiment, a pressure sensor is used as the water depth sensor, and a sensor using electrical conductivity is used as the water sensor, but the invention is not limited to these. A distance sensor or the like that measures distance may be used, or a water sensor may be a temperature sensing element or the like that generates a voltage due to the difference in temperature between air and air. Furthermore, it is possible to easily configure a plurality of sensors that detect not only water depth but also water temperature and salinity.

[Effects of the Invention] As described above, according to the present invention, since a water sensor is used in which the power supply electrode and the detection electrode are formed on the side surface of the insulating substrate with a sharp edge angle between them, the electrical conductivity between them is This has the effect that information on water entry and water separation from the device can be accurately distinguished depending on the presence or absence of the current, that is, whether or not current flows between both electrodes. In this case, when the depth meter enters water as intended, it can be used as a trigger to start the operation of the depth meter.
The water depth can be accurately measured without malfunction by setting this point as the water depth value of 0. On the other hand, when taking off water, water adhering between the two electrodes can be cut off by the presence of the ridge, so even if water adhesion occurs on land after taking off water, it can be cut off immediately, preventing malfunctions when the device is turned off. This has the effect of preventing unnecessary power consumption.

Further, since the decoder means constituting the present invention has the function of converting the signal from the storage circuit into a signal suitable for the output signal for display and subtracting the reference value of the storage circuit from the measured water depth value, accurate water depth values can be obtained. It has an effect that can be displayed all the time.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of a configuration for detecting water depth using a portable electronic depth gauge according to the present invention, and FIG. 2 is a schematic structural perspective view showing an embodiment of a water sensor according to the present invention. be. In the figure, 1 is a pressure sensor, 2 is a detection circuit,
3 is a decoder, 4 is a memory circuit, 7 is a water sensor, 8
1 is a control circuit, 9 is a timing circuit, 11 is an insulating substrate, 1
2 is a power supply electrode, and 13 is a detection electrode.

Claims (1)

[Scope of Claims] 1. A power supply electrode and a detection electrode disposed on two side surfaces of an insulating substrate having a sharp edge formed by two side surfaces, separated from each other around the edge angle;
It consists of a detection resistor with one terminal connected to this detection electrode, and occurs when the entire body is immersed in water while a voltage is applied between the power supply electrode and the other terminal of the detection resistor. a water sensor that extracts the potential of the detection electrode as an output signal; a pressure sensor that outputs a pressure signal according to the water depth; and a pressure sensor that is connected to this pressure sensor and automatically becomes operational upon input of a signal from the water sensor. A detection circuit that performs a detection operation intermittently in synchronization with a signal from a clock circuit, a decoder means that converts the signal from the detection circuit into a water depth value signal and outputs it, and stores the water depth value signal at the time of initial entry into the water as a reference value. a storage circuit, and the decoder means has a function of outputting a value obtained by subtracting the reference value of the storage circuit from the measured water depth value to the display driving means as a water depth value signal for display. Electronic depth gauge.