JPH11201794A - Gas shut-off method when the voltage drops in a gas meter using a water treatment device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To enable a shut-off valve to be closed safely and securely even when a battery voltage is reduced and an alarm state is set. SOLUTION: A gas meter using a processing device that monitors a flow rate, a pressure, an earthquake, and the like (Steps S2 to S4) and executes a display / notification process (Step S5), a clock integration process (Step S6), and the like. When the battery voltage drop is detected and displayed and notified (see Y in step S9), a certain period (for example, 48 hours) for replacing the gas meter is operated as an alarm state. If not replaced (see Y in step S10), 1
At a time when the temperature is relatively high during the day, a shutoff output is issued (see steps S11 and S12), and the shutoff valve is closed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas meter using a processing unit such as a battery-powered microcomputer for monitoring the use state of gas and improving security, and more particularly to a gas meter after detecting a decrease in the battery capacity. The present invention relates to a gas shutoff system for improving security.

[0002]

2. Description of the Related Art Conventionally, a gas meter using a processing apparatus uses a battery as a power source, and there is a high demand for avoiding abnormalities of the gas meter using the processing apparatus from the viewpoint of gas use security. Therefore, the battery is periodically monitored for the ability to drive the battery shut-off valve, and if the battery voltage is low, an alarm state is displayed to notify the gas user or maintenance person by a display / notification function. . Also, when the battery voltage drops, shutting off the shut-off valve so that the gas cannot be used immediately can be troublesome for gas users.
In general, the gas is shut off so that the gas cannot be used after a certain grace period has elapsed from the low battery warning state in preparation for replacing the gas meter. Since a replacement gas meter can usually be prepared in one to two days, software for a gas meter using a processing device is prepared so as to secure more time for an alarm. The reason why the alarm state is finally cut off is to stop using gas before the battery is completely exhausted due to failure of the display / notification function.

[0003] As a method of detecting a decrease in battery capacity, there is a method for driving a maximum load in a gas meter using a processing apparatus or a pseudo load equivalent to the load for a time required to drive the maximum load. During the load current,
The voltage detection circuit detects that the terminal voltage of the load has dropped below a predetermined value, sends a signal to the processing device as a control device, and displays a low battery capacity or issues a notification. General.

In a gas meter using a processing device, when it is determined that gas is abnormally used, a shut-off valve is driven to stop the gas supply. Battery is the maximum load. Therefore, a decrease in the battery capacity is determined for a case where the load is the shutoff valve. It is a coil that drives the shut-off valve, and when the coil is energized for 50 ms (ms: millisecond) or more, the valve closes and the gas can be stopped. Further, this shut-off valve is of a self-holding type that mechanically holds the valve closed even when the energization is stopped in order to reduce battery consumption of the gas meter using the processing device (the energizing direction is opposite to the reverse direction). Then, some valves can be opened.) The equivalent impedance of the valve is, for example, 10Ω.

FIG. 7 shows a conventional example of a gas meter using such a processing apparatus, and FIG. 8 shows the relationship between a command to supply current to a dummy load and the terminal voltage of a battery. The circuit configuration of FIG.
, And is driven by the lithium battery 2. This system monitors signals from a gas flow sensor 9, a pressure sensor 10, and a seismic sensor 11, and when an abnormality in gas usage, an abnormality in pressure, or occurrence of an earthquake is detected, the processing device 1 is shut off. A command is issued to the valve driving transistor 8, the shutoff valve 5 is closed, and the supply of gas is stopped. The dummy load 3 is for detecting a decrease in the battery capacity, has the same impedance as the shut-off valve 5, and has its terminal voltage input to the voltage detection circuit 4. Voltage detection circuit 4
Outputs a logical output to the processing device 1 when the terminal voltage at the time of energization falls below a predetermined value. A signal is output from the processing device 1 by this output, and the display / notification means 12 displays / notifies a decrease in battery capacity.

A method for detecting a decrease in battery capacity will be described below. First, when a command from the processing device 1 is sent to the battery capacity test transistor 7 (see time 0 in FIG. 8),
The transistor 7 is turned on (ON), the pseudo load energizing transistor 6 is immediately turned on, and a current flows through the pseudo load 3. As a transistor for energizing the dummy load 3, if it is equivalent to the shut-off valve driving transistor 8, a single transistor can be directly used as the dummy load 3.
However, in order to reduce costs, the configuration uses two inexpensive transistors (6, 7).

[0007] The terminal voltage of the dummy load 3 is
Has been entered. The voltage detection circuit 4 is a circuit or an element that outputs a logical output when an applied voltage becomes equal to or lower than a predetermined voltage, as represented by, for example, a voltage detection IC. In this case, the predetermined voltage of the voltage detection circuit 4 is set to the minimum operating voltage of the shutoff valve 5. One example of the minimum operating voltage of the shut-off valve 5 in the case of a lithium battery is 1.8V. When the terminal voltage of the dummy load 3 in the energized state becomes equal to or lower than the predetermined voltage, the voltage detection circuit 4 outputs a logical output to the processing device 1, and upon receiving this output, the processing device 1 displays and outputs the logical output.
A signal is output to the notifying unit 12, and the display / notifying unit 12 issues a display of the battery capacity reduction by the light emitting diode (LED) and a notification of the battery capacity reduction by communication. It should be noted that the processing device 1 does not accept the output signal of the voltage detection circuit 4 when the power supply command to the pseudo load 3 is not issued from the processing device 1.

Next, the relationship between the energizing command and the terminal voltage of the battery when the dummy load 3 is actually energized will be described with reference to FIG. When an energization command is issued at time 0 and a current flows through the dummy load 3, the terminal voltage of the battery decreases. The energization command is sent for 100 ms longer than 50 ms, which is the time required for driving the shut-off valve 5. During this 100 ms, the processing device 1 monitors the output signal of the voltage detection circuit 4. Therefore, if the terminal voltage of the dummy load 3 does not drop below the predetermined value during this 100 ms, the logic output is not output from the voltage detection circuit 4 and the battery capacity is determined to have no problem. Since there is a difference between the terminal voltage of the dummy load 3 and the terminal voltage of the battery by the voltage drop of the dummy load energizing transistor 6, the terminal voltage of the dummy load 3 is also substantially the same as the terminal voltage of the battery in FIG. It can be treated as decreasing with the tendency.

Conventionally, such detection of a decrease in battery capacity is performed, for example, every 25 hours. The reason is to minimize battery consumption due to the above operation. The reason why the period is set to be one hour longer than 24 hours a day is to monitor the battery during the day and at night over about 24 days. As described above, the gas meter using the processing device determines a decrease in the ability to drive the shut-off valve with the battery and detects a decrease in the battery voltage. When a battery voltage drop is detected, the gas meter using the processing device displays a warning after a display / report, and then shuts off the gas for a certain period of time, for example, 72 hours (3 days later) in a state where the gas cannot be used again. Close the valve.

[0010]

As described above, the gas meter using the processing apparatus goes through a warning state in which gas can be used for a certain period of time after detecting a decrease in battery voltage, and then enters a cut-off state in which gas cannot be used. Since the gas meter using the processing device is replaced at the same time as the replacement cycle of the gas meter for 10 years, the design value of the battery capacity is designed to be usable for 10 years, but the voltage drop is detected within less than 10 years In fact, there are many cases where the temperature falls in winter, especially during winter. This is considered to be one of the causes of the decrease in the shut-off valve driving capability at low temperatures. If the gas meter is not replaced before the battery voltage drop warning state is switched to the cutoff state, it is required that the shutoff valve be securely closed even when the battery capacity in winter is reduced due to, for example, display or notification failure. Is done. FIG. 6 shows the temperature characteristics of the battery usage and the terminal voltage of the battery when the shutoff valve is driven. From the figure, it can be seen that the terminal voltage of the battery is higher when the ambient temperature is higher when the shut-off valve is driven, and the ability to drive the shut-off valve is higher.

However, in the above-described method in which the battery voltage is reduced to be in the alarm state and the power is cut off after a certain period of time, there is a high possibility that the power is turned off when the winter night is the lowest. That is, since voltage monitoring is conventionally performed for 25 hours, voltage monitoring during the day and night is performed over about 24 days. If a voltage drop is detected, the voltage is shut off and output 72 hours later. If a voltage drop is detected in step (1), the output is cut off at night. what if,
Even if the time is increased or decreased from 72 hours to 12 hours, if the time is constant, there is no guarantee that the timing of shut-off output from the low alarm state may be in the daytime when the temperature rises relatively even in winter. Accordingly, an object of the present invention is to make it possible to more reliably close the shut-off valve even in a battery voltage drop warning state, in consideration of the battery temperature characteristics.

[0012]

In order to solve such a problem, according to the first aspect of the present invention, when the battery voltage of a gas meter using a processing device is in a low alarm state, gas can be used for, for example, 48 hours. Try to stay state, that is,
When a low alarm condition is detected, the elapse of time is monitored by a built-in clock, and when 48 hours have elapsed, shutoff output is performed at 12:00 noon to stop use of gas.
According to the second aspect of the present invention, an A / D converter capable of taking in the battery voltage with an analog value is provided, and the battery voltage is continuously monitored with the analog value even in the low alarm state.
When the battery voltage becomes maximum within 72 hours from the time, the cutoff output is performed. According to the third aspect of the present invention, a temperature sensor capable of monitoring the temperature with an analog value is provided, and when the ambient temperature of the gas meter becomes maximum within 48 hours to 72 hours of the lowering warning state as in the second aspect, The output is cut off.

Further, according to the present invention, an optical sensor capable of detecting the surrounding brightness, for example, a phototransistor, an amplifier and an A / D converter capable of taking in an analog value are provided. From 7
When the surrounding brightness becomes maximum within two hours, the cut-off output is performed. According to a fifth aspect of the present invention, a sound collector such as a condenser microphone, an amplifier, and an A / D converter capable of capturing an analog value are provided for the audio signal around the gas meter.
If the signal of the voice band around the gas meter exceeds a certain fixed value within two hours, it is determined that it is during the day, and cutoff output is performed.

[0014]

FIG. 1 is a flow chart showing a first embodiment of the present invention. This shows a processing operation by the processing apparatus 1 as shown in FIG. 7, and operates, for example, every 100 ms (see step S1). That is, the gas meter using the processing device monitors the flow sensor, the pressure sensor, and the seismic sensor every 100 ms (see steps S2 to S4), displays and reports (see step S5), and monitors the clock every 100 ms as in the conventional example. Integration processing (step S6
And the like, and if the battery voltage monitoring timing is 25 hours (see step S7), the battery voltage is checked (see step S8).

When the battery voltage is checked and a voltage drop is detected (yes (Y) in step S9), 48 hours are counted from the detection point, and after the elapse of 48 hours (see Y in step S10), the processing device The current time is determined with reference to the clock in the gas meter using the command. For example, if it is 12:00 noon (see Y in step S11), a cutoff output is issued (see step S12). In this way, when the gas meter using the processing device detects a decrease in the battery voltage and displays / notifies the battery voltage, the gas meter is operated in an alarm state for at least 48 hours as a grace period for replacing the gas meter. If the gas meter is not replaced yet, the cut-off output can be performed at a time when the temperature is relatively high in one day and the condition is good for the battery.

FIG. 2 is a block diagram showing a second embodiment of the present invention. That is, the feature is that an A / D converter 13 for taking in the battery voltage into the processing device 1 in an analog amount is provided in place of the voltage detection circuit 4 for detecting one point of 1.8 V in FIG. This is because it is known that the battery has a temperature characteristic as shown in FIG. 4 even when the battery is open. For example, when a 10 Ω shutoff valve is driven, it is advantageous when the open voltage of the battery is high. It depends.

The operation in the flowchart of FIG. 1 in the case of the configuration as shown in FIG. 2 is changed as follows. That is, in steps S1 to S10, the analog amount is converted into a digital amount by the A / D converter instead of the voltage detection circuit and is taken into the microcomputer, and the threshold value of the battery drop 1.8V
Has not changed at all except for the determination by the processing device. However, in step S11, the open-circuit voltage of the battery is monitored, and it is confirmed that this is the maximum.
To output the cutoff output. The reason why the open state of the battery is monitored is that a drop in the battery voltage has already been detected, and starting the pseudo load in a state where the open voltage of the battery is low will place an excessive burden on the weak battery. .

FIG. 3 is a configuration diagram showing a third embodiment of the present invention. That is, the present embodiment is characterized in that a temperature sensor 14 is provided in the conventional device shown in FIG. It is desirable to use a low-power-consumption type temperature sensor that oscillates an analog value as a digital pulse, for example. The operation in the flowchart of FIG. 1 in the case of the configuration as shown in FIG. 3 is the same as the conventional case in steps S1 to S10. When the temperature sensor 14 is driven in step S11 and the temperature becomes maximum, The difference is that a cutoff output is output in step S12.

FIGS. 4 and 5 show the fourth and fourth embodiments of the present invention, respectively.
It is a lineblock diagram showing a fifth embodiment. When the configuration is as shown in FIGS. 4 and 5, the operation of the flowchart in FIG.
Steps S1 to S10 are the same as those described above. In step S11, the optical sensor circuit is driven. When the brightness of the surroundings is maximized, the circuit is shut off in step S12, or the sound collecting unit circuit is driven in step S11. When the voice signal exceeds a certain threshold value, cut-off output is performed in step S12.

[0020]

According to the present invention, the shutoff for stopping the use of gas after detecting the voltage drop of the gas meter using the processing apparatus is performed in consideration of the temperature characteristics of the battery.
There is an advantage that it is possible to avoid the possibility that the interruption is not possible, and it is possible to improve security.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a first embodiment of the present invention.

FIG. 2 is a configuration diagram showing a second embodiment of the present invention.

FIG. 3 is a configuration diagram showing a third embodiment of the present invention.

FIG. 4 is a configuration diagram showing a fourth embodiment of the present invention.

FIG. 5 is a configuration diagram showing a fifth embodiment of the present invention.

FIG. 6 is an explanatory diagram of a temperature characteristic example of a battery.

FIG. 7 is a configuration diagram showing a conventional example of a gas meter using a processing apparatus.

FIG. 8 is an explanatory diagram of an example of a battery capacity detection method in FIG. 7;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Processing apparatus (microcomputer), 2 ... Lithium battery, 3 ... Simulated load, 4 ... Voltage detection circuit, 5 ... Shut-off valve,
6, 7, 8, 14, 15 ... transistor, 9 ... flow rate sensor, 10 ... pressure sensor, 11 ... seismic sensor, 12 ... display / notification means, 13 ... A / D converter, 14 ... temperature sensor, 15
... phototransistor, 16 ... amplifier, 17 ... condenser microphone.

Claims (5)

[Claims] 1. A processing device, a shut-off valve, a pseudo load equivalent to a shut-off valve, a voltage detection means, a display / notification means, a clock, and a battery as a power supply, and a current is supplied to the pseudo load. By determining the voltage drop of the battery, and after detecting the battery voltage drop, the gas meter using the processing device that can use gas only for a certain period in consideration of the replacement period of the gas meter using the processing device In the above, a period monitoring means for monitoring the certain period is provided, and after the certain period elapses, a time period during which the daytime temperature is high is selected with reference to the current time, and the shutoff valve is set in this time period. A gas shut-off method when the voltage of a gas meter drops using a processing device characterized by closing. 2. A voltage monitoring means capable of monitoring the open voltage of the battery by an analog amount in place of the period monitoring means, and considering a replacement period of a gas meter using a processing device from detection of a battery voltage drop. After a certain period, a time zone in which the open-circuit voltage of the battery is maximized is selected, and the shut-off valve is closed during this time zone, when the voltage of the gas meter using the processing apparatus according to claim 1 drops. Gas shut-off method. 3. A temperature sensor capable of monitoring an ambient temperature of a gas meter using the processing device by an analog quantity in place of the period monitoring means, and a replacement period of the gas meter using the processing device from a battery voltage drop detection. 2. The voltage drop of the gas meter using the processing apparatus according to claim 1, wherein a time zone in which the ambient temperature is highest after a certain period of time has been considered is selected, and the shutoff valve is closed during this time zone. Gas shut-off method at the time. 4. An optical sensor and an amplifying circuit capable of monitoring the brightness around a gas meter using the processing device with an analog quantity in place of the period monitoring means, and using the processing device based on detection of a decrease in battery voltage. 2. The processing apparatus according to claim 1, wherein a time zone in which the surrounding brightness is highest after a certain period has elapsed in consideration of a gas meter replacement period, and the shut-off valve is closed during this time zone. Gas shut-off method when gas meter voltage drops using 5. A gas meter using a processing device based on detection of a battery voltage drop by providing a microphone and an amplification circuit capable of monitoring an audio signal around a gas meter using the processing device in an analog amount instead of the period monitoring means. 2. The processing device according to claim 1, wherein after a certain period of time has elapsed in consideration of the replacement period, a time zone in which the surrounding audio signal is highest is selected, and the shutoff valve is closed during this time zone. Gas shut-off method when the voltage of the gas meter used drops.