JPH0348115A - Electronic water depth meter - Google Patents

Abstract

PURPOSE:To prevent an erroneous pressure from being set as a reference pressure by setting a preset specific pressure as a reference pressure when the pressure detected by a pressure sensor is not lower than a predetermined pressure. CONSTITUTION:When a mode switching switch SM of a switch part 8 is manipulated in the clock mode, 1 is set to a mode register M of a RAM 9 to switch the mode to a water depth measuring mode. The pressure detected at this time by a pressure sensor 5 is stored in a register P. Thereafter, it is judged whether a detected pressure P' is smaller than a predetermined pressure, for example, 1.136kg/cm<2> 1m below the surface of the sea at the standard atmospheric pressure. When P'<1.136kg/cm<2> is held, it is so judged that the SM is not manipulated in the water, and the pressure P' is stored in a register Po as a reference pressure. Meanwhile, when P'>=1.136kg/cm<2> is held, it is so judged that the pressure in the water is taken as a reference pressure, and the pressure of the surface of the sea under the standard atmospheric pressure stored beforehand is stored in the register Po as a reference pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an electronic depth gauge that calculates water depth from pressure detected by a pressure sensor.

[Prior art and its problems]

With a depth meter that calculates water depth from the pressure detected by a pressure sensor, the water depth calculated from the underwater pressure detected by the pressure sensor may be different from the actual water depth due to changes in the atmospheric pressure at the measurement point or the influence of the altitude of the measurement point. may have a different value. Therefore, for example, before starting measurement, the pressure at the reference point (for example, the pressure at the water surface) is set as the reference pressure, and the water depth is calculated from the pressure difference between the reference pressure and the pressure detected by the pressure sensor during diving. I have to.

For example, if the configuration is such that when switching from watch mode to depth gauge mode, the pressure detected by the pressure sensor is taken in as the reference pressure, the switch to depth gauge mode will be correctly executed before the dive begins. If this is done, the correct reference pressure can be set and the accurate depth of the diving point can be obtained.

However, sometimes the user may forget to switch the mode and switch to the depth meter mode underwater. In this case, since the pressure at the point underwater when the mode is switched is taken as the reference pressure, the water depth calculated based on the reference pressure is shallower than the actual water depth.

This results in an incorrectly displayed water depth that is shallower than the actual depth.
There was a problem in that it was a serious defect that could affect the life of the Diaper.

[Purpose of the invention]

An object of the present invention is to provide an electronic water depth gauge that can prevent incorrect pressure from being set as a reference pressure and display the correct water depth.

[Key points of the invention]

In a water depth gauge that calculates water depth from a set reference pressure and a pressure detected by a pressure sensor, when the setting of the reference pressure is instructed by a switch means, the pressure sensor detects the reference pressure as the reference pressure to be set. When the pressure measured is equal to or higher than a predetermined pressure, a preset specific pressure is set as the reference pressure, and it is possible to prevent a pressure measured underwater or the like from being erroneously set as the reference pressure.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a circuit diagram of an electronic wristwatch with a depth gauge according to an embodiment of the present invention.

The oscillation circuit 1 is a circuit that generates a clock signal with a constant period, and outputs the generated clock signal to the frequency dividing circuit 2. The frequency dividing circuit 2 divides the frequency of the clock signal, for example, I
A Hz clock signal is created and output to the counting circuit 3.

The clock counting circuit 3 counts the IHz clock signal to obtain time data consisting of the current time and date, and outputs the time data to the CPU 4. It also outputs a 1/3 Hz measurement timing signal to the CPU 4, which serves as a reference for water depth measurement.

The CPU 4 is a central processing unit that controls the entire circuit. For example, in the clock mode, the CPU 4 updates the time based on time data from the counting circuit 3, and in the depth gauge mode, updates the time based on the time data from the counting circuit 3. It runs every second to measure water depth.

The pressure sensor 5 is a sensor that detects atmospheric pressure or water pressure, and outputs an analog pressure signal corresponding to the pressure to the amplifier circuit 6. The amplifier circuit 6 is a circuit that amplifies the analog pressure signal from the pressure sensor 5 to a predetermined signal level. The analog pressure signal amplified by the amplifier circuit 6 is converted into a digital pressure signal by the A/D conversion circuit 7 and output to the CPU 4. Further, these pressure sensor 5, amplifier circuit 6, and A/D conversion circuit 7 are connected to the CPU 4 to 3.
It operates according to the drive signal given every second and measures the water depth.

Although not shown, the switch section 8 includes a mode changeover switch SHs for switching between a watch mode and a depth meter mode, a time adjustment switch that is operated when adjusting the time in the watch mode, etc., and these operation signals are sent to the CPU 4.
Output to.

The RAM 9 is a memory in which writing and reading are performed under the control of the CPU 4, and as schematically shown in FIG. 1, it corresponds to the register P for storing the measured pressure and the register PO1 for storing the reference pressure. It has a mode register M for storing the numerical value.

The display drive circuit 10 is a circuit that converts time data, water depth data, etc. output from the CPU 4 into signals for driving display elements of the display section 11, and outputs the created display signals to the display section 11.

The display unit 11 is composed of a liquid crystal display or the like, and displays the current time, the water depth of the diving point, etc.

Next, the operation of the embodiment with the above configuration will be explained as shown in FIGS. 2 to 4.
This will be explained with reference to the flowchart shown in the figure.

FIG. 2 is a flowchart illustrating the overall operation of the embodiment.

First, in step S1 of FIG. 2, it is determined whether any switch has been operated.

When the switch is operated, the next switch process of step S2 is executed.

This switch processing will be explained below with reference to the flowchart of FIG.

First, in step Sll of FIG. 3, it is determined whether the mode changeover switch SN has been operated.

If it is the switch SN that has been operated, the process advances to step S12 and it is determined whether the value of the mode register M is rQJ.

When M=1, that is, when switch S9 is operated in depth gauge mode, 1. Proceeding to step S13, the mode register M is set to "0", the mode is switched to the clock mode, and the switch processing is completed.

On the other hand, when M=O, that is, when the switch SN is operated in the watch mode, the process proceeds to step S14, where the mode register M is set to "1" and the mode is switched to the depth meter mode.

Then, in the next step S15, the pressure detected by the pressure sensor at that time is stored in the register P. after that,
In step S16, it is determined whether the detected pressure is smaller than a predetermined pressure value (for example, the pressure 1 m below the sea level under standard atmospheric pressure (1°033 kg/d), 1.136 kg/c ()). .

When P < 1.136 kg/coil, it is determined that the operation of switch S9 was not performed underwater,
Proceeding to step S17, the pressure value P measured this time is stored in the register Po as a reference pressure.

On the other hand, in the determination at step 316, P≧1.136
kg/c4, it is determined that the underwater pressure was switched to the water probe mode by mistake and the underwater pressure was taken in as the reference pressure, and the process proceeds to step 31B to memorize it in advance. A pressure of 1.033 kg/c4 at sea level (Om) under standard atmospheric pressure is stored in the register Pa as a reference pressure.

The value taken in as the reference pressure at the time of mode switching in this way is set to a predetermined pressure value (for example, 1.133 kg/cf
fl), and if the taken-in pressure is larger than the predetermined value above, the pressure at sea level under standard atmospheric pressure (1,033 kg/d) is set as the reference pressure, so it is possible to accidentally prevent diving while diving. Even if the mode is switched to , the pressure at the diving point is not set as the reference pressure.

Therefore, a water depth shallower than the actual water depth is not displayed, and it is possible to prevent the dipper from erroneously diving to a deep water depth.

In the determination of step Sll, the operated switch is switch SN.
If not, this means that another switch has been operated to adjust the time, etc., and the process advances to step S19 to execute the corresponding switch processing.

When the switch processing is completed as described above, the process proceeds to step S3 in FIG. 2, and the value of the mode register M is set to
”.

If M=0, it is the clock mode, and the process proceeds to step S4, where the time data from the counting circuit 3 is displayed on the display section 11.

If M=1, it is the depth gauge mode, and step S
Proceed to step 5 and determine whether the measurement timing is every 3 seconds.

If the measurement timing is not every 3 seconds, the process directly proceeds to the display process of step S7, and the water depth calculated from the pressure stored in the register P is displayed on the display unit 11.

On the other hand, when the measurement timing is every 3 seconds, the next measurement process of step S6 is executed.

This measurement process will be explained below with reference to the flowchart shown in FIG.

First, in step S21 of FIG. 4, the pressure sensor 5
Pressure data detected every second is stored in register P. Then, in the next step S22, the difference between the measured pressure of the register P and the reference pressure of the register P0 is divided by the pressure increase value of 0.10256 kg/cn per 1 m of seawater to calculate the water depth at that point.

Once the water depth of the diving point has been calculated by the measurement process in this way, the display process of step S7 in FIG. 2 is then executed to display the calculated water depth on the display unit 11.

As described above, according to the above embodiment, even if the pressure at the diving point during diving is taken as the reference pressure by mistake, if the pressure is equal to or higher than the predetermined pressure value, then the sea level pressure under standard atmospheric pressure is set as the reference pressure, a water depth shallower than the actual water depth will not be displayed, and it is possible to prevent a false water depth from being displayed and endangering the dipper.

In the above embodiment, the pressure detected by the pressure sensor at the time of mode switching is taken in as the reference pressure, but the present invention is not limited to this and can be applied to pressure gauges with other configurations. The present invention can also be applied to a case where a switch is provided to instruct the input of , and the pressure measured when the switch is operated is taken in as the reference pressure.

In addition, the predetermined pressure value that serves as the standard for determining whether to set the measured pressure as the reference pressure or to set a specific pressure value stored in advance as the reference pressure is the value described in the example, 1 It is not limited to .136 kg/c-, but any value can be set as long as the safety of the dial is ensured.

Furthermore, the present invention is not limited to incorporating the water depth meter described in the embodiment into an electronic wristwatch, but may also be incorporated into other equipment, and of course may be a device dedicated to the water depth meter.

(Effects of the Invention) According to the present invention, underwater pressure is not erroneously set as the reference pressure, so a water depth shallower than the actual water depth is displayed, and the diver is prevented from diving at a dangerous depth. It can be prevented.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of an electronic wristwatch with a depth gauge according to an embodiment of the present invention, and FIGS. 2, 3, and 4 are flowcharts illustrating the operation of the embodiment. 4...CPU. 5...Pressure sensor, 9...RAM.

Claims (1)

[Claims] In an electronic water depth gauge that determines water depth from a set reference pressure and a pressure detected by a pressure sensor, there is provided a switch means for instructing the setting of the reference pressure, and when the setting of the reference pressure is instructed by the switch means; When the pressure detected by the pressure sensor is lower than a predetermined pressure, the detected pressure is set as the reference pressure, and when the detected pressure is higher than the predetermined pressure, the preset specific pressure is set as the reference pressure. An electronic water depth gauge characterized by comprising: a reference pressure setting means for setting a reference pressure as a reference pressure;