JP2003051086A - Radio meter reading terminal device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To extend battery life by suppressing surplus current consumption when the voltage of the battery being an operating power supply in a sleep mode of a radio meter reading terminal device surpasses a minimum operation maintenance voltage due to a rise in temperature. SOLUTION: A first battery 11 is a power supply that periodically stops receiving standby and supplies operating power of a sleep band where the minimum necessary limit operation of a CPU 7 performs, an A/D converter 21 measures a discharge voltage of the first battery 11 in a prescribed interval, a step-down regulator 19 supplies power as a minimum operation maintenance voltage via a switch A in the case the discharge voltage surpasses the minimum operation maintenance voltage, and the voltage of the first battery 11 is subjected to direct power supply through a switch C in the case the discharge voltage is the minimum operation maintenance voltage or is less than the minimum operation maintenance voltage.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless meter reading terminal device for automatically metering the amount of electricity, gas, water, etc. used by wireless communication such as PHS. It is related to suppression and extension of battery life.

[0002]

2. Description of the Related Art FIG.
FIG. 6 is a block diagram of a configuration of a conventional wireless meter reading terminal device shown in No. 881, and FIG. 6 is a block diagram of a power supply circuit in the conventional wireless meter reading terminal device. In the figure, 1 is a wireless meter reading terminal device, 2 is an antenna, 3 is a wireless transceiver, 4 is a memory,
5 is a weighing sensor (not shown) of a weighing device, 6 is a weighing sensor 5
A buffer that converts the weighing signal from the device into a pulse, 7 is a CP
U and 8 are clocks, and 20 is a power supply circuit that supplies operating power of the wireless meter reading terminal device 1. Reference numeral 11 is a first battery for standby that continuously takes out a small current, and reference numeral 12 is a second battery for operation that can intermittently take out a large amount of electric power. 13, 14
Is a switch which is controlled to be turned on / off by the CPU 7 and which switches a power supply destination; 15 is a step-up regulator for stepping up the voltage of the second battery 12 to a voltage at which the CPU 7 and the wireless transmission / reception section 3 can be sufficiently operated; It is a diode for prevention. 18 is a step-down regulator, which is a CPU 7,
The voltage is lowered to a level required at least for the operation of the memory 4 or the like to suppress the consumption of the battery.

FIG. 7 shows an operation sequence of the wireless meter reading terminal device at the time of meter reading, where A is a sleep band, B is a standby mode, and C is a transmission mode. The sleep zone A includes a carrier detection zone for confirming the presence / absence of a signal from the outside for a regular short time, and a sleep zone for stopping the active operation of the CPU 7 and the memory 4 etc. to reduce the current consumption and maintaining only the minimum operation function. Composed of. The carrier detection zone is composed of 15 ms and the sleep zone is composed of 1.5 seconds. The carrier detection band consumes more current than the sleep band in order to perform the receiving operation of the wireless transmission / reception unit 3, but the time width is shortened to suppress the overall power consumption.

Next, the operation will be described. In the sleep band, the switch 13 is turned on so that the operating power is supplied from the first battery 11 to the CPU 7, the memory 4, the wireless transmission / reception unit 3, etc.
4 is off. When a communication message addressed to itself is confirmed from the outside in the carrier detection band, standby mode B of the reception system
Becomes In the standby mode B, the meter reading data message is organized according to the instruction of the communication message, and the process proceeds to the transmission mode C. In the transmission mode C, a large amount of electric power is required to transmit the meter-reading data telegram to the meter-reading central apparatus (not shown), so the boost regulator 15 and the switch 14 are turned on so that the second battery 12 supplies electric power. During this period, the switch 13 is turned off to prevent the consumption of the first battery 11. By the way, the current consumption in each mode is about 10μ in the sleep band.
A, about 30 mA in carrier detection band and standby mode B,
In the transmission mode C, it is about 500 mA.

[0005]

Since the conventional wireless meter reading terminal device is formed as described above, the step-down regulator 18 is provided with a large capacity capable of withstanding the current in the transmission mode. Therefore, in the sleep band and the standby mode, power is supplied from the first battery 11 to the CPU 7, the memory 4, and the like via the step-down regulator 18.
It was necessary to constantly operate the step-down regulator 18.
Therefore, for example, even in the sleep period, there is a problem that a loss occurs due to the control by the step-down regulator 18 at all times, the stored energy of the battery cannot be fully utilized, and the battery life is shortened.

Since such a wireless meter reading terminal device is installed outdoors, the temperature rise under direct sunlight and low temperatures during the cold winter. Generally, a lithium battery is used as the first battery 11 which is a power supply for operation standby operation including a sleep band, and the discharge voltage of this lithium battery changes with temperature as shown in FIG. In addition, since the discharge voltage decreases as the depth of discharge of the battery advances, it is 3.2 V at a high temperature (60 ° C.) when the battery is new, and 2.6 V at a low temperature (−10 ° C.) when the discharge is advanced. There is nothing. Therefore, the minimum operation maintaining voltage of the CPU 7 and the memory 4 in the sleep band is set to 2.6V, for example. Battery discharge voltage is 2.
When the voltage is higher than 6V, the impedance of the CPU 7 and the memory 4 does not depend on the temperature and is almost constant. Therefore, when the discharge voltage of the battery is high, an extra current flows in proportion to the voltage.

Further, the step-down regulator 18 is used to secure an output voltage of 3 V or more in order to supply the electric power necessary for the transmission operation of the wireless transmission / reception section 3, so that the first battery 1
While 1 holds the discharge voltage of 3 V or more, an extra current equivalent to 0.4 V, which is the difference from the minimum operation maintaining voltage of 2.6 of the CPU 7, the memory 4, etc., is consumed in the sleep band. Although it is 0.4V, it is 15 for the minimum operation sustaining voltage.
% Extra current consumption. In particular, such a wireless meter reading terminal device is required to be used continuously for 10 years without battery replacement from installation, and it is necessary to suppress extra battery consumption during the sleep band, which occupies most of the installation period.

The present invention has been made to solve the above problems, and an object thereof is to reduce the extra current consumption of the battery in the sleep band and prolong the battery life.

[0009]

(1) A wireless meter-reading terminal device according to claim 1 of the present invention has a function of wirelessly receiving a meter-reading command and returning a meter-reading value as a telegram, and receiving the command while waiting for reception. In a wireless meter terminal device equipped with a battery that supplies the operating power in the sleep mode in which the standby is periodically stopped and the above-mentioned functions perform the minimum necessary operations, the discharge voltage of the battery is detected, and the detected voltage is the sleep voltage. The operating power for sleep is supplied directly from the battery when the voltage does not reach or does not reach the range of the minimum operation sustaining voltage of the time operation, and when it exceeds the range of the minimum operation sustaining voltage, it is set within the range. The voltage of the battery is dropped to supply operating power during sleep.

(2) A wireless meter reading terminal device according to a second aspect of the present invention has a function of wirelessly receiving a meter reading command and returning a meter reading value as an electronic message, and periodically suspends the waiting for reception while waiting for receiving. Then, in a wireless meter reading terminal device equipped with a battery that supplies operating power during sleep in which the above-mentioned function performs a minimum required operation, the discharge voltage of the battery is detected, and the detected voltage is within the range of the minimum operation maintaining voltage. In this case, the operating power for sleep is supplied directly from the battery, and when it exceeds the range of the minimum operation sustaining voltage, the voltage is dropped to fall within that range to supply the operating power for sleep. When the range of the operation maintaining voltage is not reached, the voltage of the battery is raised so as to be within the range and the operating power during the sleep is supplied.

(3) In the wireless meter terminal device according to claim 3 of the present invention, in claim 1 or 2, when the discharge voltage of the battery does not reach the range of the minimum operation maintaining voltage, the battery life notice is given. The message is sent.

(4) The wireless meter reading terminal device according to claim 4 of the present invention is the wireless reading terminal device according to any one of claims 1 to 3, wherein the discharge voltage of the battery can follow the temperature change of the outside air.
It is detected periodically at 3-hour intervals or irregularly at any time.

(5) A wireless meter reading terminal device according to a fifth aspect of the present invention, in any one of the first to fourth aspects, detects the power supply for operating the communication function and the meter reading function, and the discharge voltage of the battery. The power supply used for this purpose uses a battery different from the above battery.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. 1 is a power supply circuit diagram of a wireless meter-reading terminal device according to Embodiment 1 of the present invention,
FIG. 2 is a flow chart of the voltage control of the present invention. The overall block configuration of the wireless meter-reading terminal device is shown in FIG.
It is the same as and is omitted.

In the figure, 7 and 11 to 17 are the same as those in the conventional device described above. 20 is a power supply circuit of the wireless meter-reading terminal device, 19 is a step-down regulator, and the input voltage is CP
2.6V which is the minimum operation maintaining voltage of U7 and memory 4
Output voltage. It is desirable that the step-down regulator 19 has a minimum control power for step-down, and a fixed output voltage type positive voltage voltage regulator IC is adopted. Reference numeral 21 is an A / D converter for measuring the discharge voltage of the first battery 11 by the CPU 7, 22 is a timer controlled by the CPU 7, and the operating power source of the A / D converter 21 is the second battery 1
Control the time obtained from 2. Reference numeral 23 is a diode for preventing current backflow, 24 is a switch C, and the first battery 11
The discharge voltage of 1 is directly applied to the CPU 7 and the memory 4 which are loads without passing through the step-down regulator 19. The switch 13 is referred to as a switch A and the switch 14 is referred to as a switch B for the sake of identification in the description. As the switches A13, B14, and C24, switches formed by switching elements of FET (field effect transistor) are used in order to reduce power consumption due to opening / closing operation.

The operation will be described with reference to the flowchart of FIG. (1) The discharge voltage of the first battery 11 changes according to its own temperature, as described above with reference to FIG. The wireless meter reading terminal device installed outdoors changes depending on the temperature of the outside air, direct sunlight, and the like. The discharge voltage of the first battery 11 is measured at a time interval (generally, 1 to 3 hours is desirable, so the timer 22 is set to 2 hours in this embodiment) that substantially follows this temperature change (step 201). . (2) The discharge voltage is converted by the A / D converter 21 into the first battery 11
The discharge voltage E is converted into a digital value and is taken into the CPU 7 for measurement. At this time, in order not to consume the current of the first battery 11 and to reduce the power consumption in the A / D converter 21,
The A / D converter 21 supplies power to the CPU 7 and the A / D converter 21 from the second battery 12 by boosting the voltage to a voltage that can operate for a short time required for voltage measurement to the CPU 7 and the A / D converter 21 (steps 202 to 204). .

(3) If the discharge voltage E of the first battery 11 is equal to or higher than the minimum operation maintaining voltage of the CPU 7 (set to 2.7 V in this embodiment) as a result of the voltage measurement, the switch C2
Turn off the switch 4 to turn on the switch A13 to prevent excessive current in the sleep band due to excessive voltage.
Voltage is reduced to 2.6V by CPU7 and memory 4
Etc. are operated (steps 205 to 207). (4) When the discharge voltage E of the first battery 11 is less than 2.7 V, the CPU 7 and the memory 4 do not need to go through the step-down regulator 19.
The switch A13 is turned off and the switch C24 is turned on so as to activate the above (steps 209 and 210). (5) And the discharge voltage E of the first battery 11 is 2.5 V
If it is less than the limit, the electronic message informs that the first battery 11 is near the end of its life (steps 208 and 211). (6) Boosting regulator 15 when the role of power supply such as measurement determination of the discharge voltage from the second battery 12 and message notification is completed.
Operation of the second battery 1
The discharge of No. 2 is prevented and the operation shifts to the sleep band operation (steps 212 and 213). (7) Since the necessity of the step-down regulator 19 is determined at intervals of 2 hours by measuring the discharge voltage E of the first battery 11, a margin of 0.1V is provided as a delay width for following the temperature change.

The temperature of the first battery 11 depends on the outside air temperature, direct sunlight, etc., and the discharge voltage E is measured at 2 hour intervals so as to follow the temperature, and switch control is performed to operate the step-down regulator 19. Whether the first battery 11 has a shallow discharge depth and the discharge voltage E is CP when the temperature is high.
When the voltage is equal to or higher than the minimum operation maintaining voltage of U7, the step-down regulator 19 lowers the voltage to the minimum operation maintaining voltage of the CPU 7 and suppresses extra current consumption, so that the battery life can be extended.

When the discharge voltage E drops near the minimum operation maintaining voltage of the CPU 7, a telegram indicating the battery life is sent to notify the administrator of the wireless meter reading terminal device in the central meter reading device. The battery life warning voltage was only temporarily reached due to the temperature decrease, and the battery life was not exhausted.The voltage recovered with the temperature change, and the battery life warning message was sent while the battery life warning voltage was repeatedly decreased. Indicates that the depth of discharge has increased when the arrival interval is shortened, and countermeasures such as replacement of the wireless meter reading terminal device can be implemented.

Embodiment 2. 3 is a power supply circuit diagram of a wireless meter-reading terminal device according to a second embodiment of the present invention, and FIG. 4 is a flow chart for voltage control according to the second embodiment. The overall block configuration of the wireless meter-reading terminal device is the same as that shown in FIG. In FIG. 3, 7, 11 to 17,
19 to 24 are the same as those described in the second embodiment. Two
Reference numeral 5 is a diode for preventing current backflow, and 26 is a step-up regulator B, which discharges the first battery 11 from a discharge voltage of 2.6V.
Boost to. A switch D 27 is on / off controlled by the CPU 7.

Embodiment 2 will be described with reference to the flowchart of FIG.
The operation will be described. Steps 201 to 21 in FIG.
3 is the same as that of FIG. 2 of the above-mentioned first embodiment, and its explanation is omitted. The discharge voltage E of the first battery 11 determined in step 401 is the minimum operation maintaining voltage of the CPU 7 (2.4 in this case).
V is adopted) to 2.7V Step-down regulator 1
The switch C is turned on and the switch A is turned off so that the discharge voltage E is directly supplied to the CPU 7 etc. without passing through 9 (steps 401 to 209). This eliminates power consumption in the step-down regulator 19. When the discharge voltage E of the first battery 11 becomes less than 2.4V, it informs by electronic message that the first battery 11 is near the end of its life (step 211). Then, the switch D is turned on to turn on the boost regulator B26.
To turn off the switch C (step 402).
~ 404).

Even if the discharge voltage E of the first battery 11 becomes less than 2.4V, the energy held in the first battery 11 is not exhausted, so that the booster regulator B26 changes the usable voltage of the CPU 7 or the like. It rises and uses the remaining energy. When the discharge voltage E is less than 2.4 V, the operating voltage of the booster regulator B26 and the voltage increase, so the first battery 1
Although the discharge of No. 1 progresses rapidly, as compared with the case of the first embodiment, even if the discharge voltage of the first battery 11 becomes equal to or lower than the minimum operation maintaining voltage of the CPU 7 or the like, the remaining energy is used to make the battery life longer. The period can be extended.

[0023]

As described above, the present invention has the following effects. (1) According to claim 1 of the present invention, when the range of the minimum operation maintaining voltage is exceeded, the voltage is reduced to supply the power for the sleeve, so that the extra current consumption of the battery is reduced and the battery life is reduced. Lengthen.

(2) According to the second aspect of the present invention, when the range of the minimum operation maintaining voltage is exceeded, the voltage is reduced to supply the power for the sleeve, and when the range of the minimum operation maintaining voltage is not reached. Since the power is boosted to supply the power for the sleeve, the extra current consumption of the battery is reduced, the battery life is extended, and the battery can be used even if the minimum operation maintaining voltage is not reached.

(3) According to the third aspect of the present invention, when the discharge voltage of the battery does not reach the minimum operation maintaining voltage, the battery life advance notice can be notified.

(4) The discharge voltage of the battery can be detected at effective predetermined intervals, and can be detected at any time.

(5) Since the battery for operating the communication function and the meter reading function is separate from the battery used during sleep, the life of the battery during sleep is extended.

[Brief description of drawings]

FIG. 1 is a power supply circuit diagram of a wireless meter-reading terminal device according to a first embodiment of the present invention.

FIG. 2 is a flowchart of voltage control according to the first embodiment of the present invention.

FIG. 3 is a power supply circuit diagram of a wireless meter-reading terminal device according to a second embodiment of the present invention.

FIG. 4 is a flowchart of voltage control according to the second embodiment of the present invention.

FIG. 5 is a configuration block diagram of a wireless meter-reading terminal device.

FIG. 6 is a block diagram of a power supply circuit in a conventional wireless meter reading terminal device.

FIG. 7 is a diagram showing an operation sequence at the time of meter reading of the wireless meter reading terminal device.

FIG. 8 is a diagram showing a relationship between a discharge depth and a discharge voltage according to temperature of a lithium battery.

[Explanation of symbols]

1 wireless meter reading terminal device, 3 wireless transceiver unit, 4
Memory, 7 CPU, 11 first battery, 12
Second battery 13, switch A, 14 switch B, 15
Step-up regulator 16, 17, 23, 25 Diode, 19 Step-down regulator 20 Power supply circuit, 21 A / D converter, 24
Switch C 26 Step-up regulator B, 27 Switch D

Claims (5)

[Claims] 1. A sleep mode having a function of wirelessly receiving a meter reading command and returning a meter reading value as a telegram, and periodically stopping the reception standby during the reception standby to perform the minimum required operation of the function. In a wireless meter terminal device equipped with a battery that supplies operating power, the discharge voltage of the battery is detected, and if the detected voltage does not reach or falls within the range of the minimum operation sustaining voltage during sleep operation, the battery is removed from the battery. A radio characterized by directly supplying operating power during sleep, and when exceeding the range of the minimum operation maintaining voltage, lowering the voltage of the battery so as to be within the range to supply operating power during sleep. Meter-reading terminal device. 2. A sleep mode having a function of wirelessly receiving a meter reading command and returning a meter reading value as a telegram and periodically stopping the reception standby during the reception standby to perform the minimum required operation of the function. In a wireless meter reading terminal device equipped with a battery that supplies operating power, the discharge voltage of the battery is detected, and when the detected voltage is within the range of the minimum operation maintaining voltage, the operating power for sleep is directly supplied from the battery. , When the range of the above-mentioned minimum operation maintaining voltage is exceeded, the voltage is dropped so as to fall within that range to supply the operating power during sleep, and when it does not reach the range of the above-mentioned minimum operation maintaining voltage, it falls within that range. As described above, the wireless meter reading terminal device is characterized in that the voltage of the battery is increased to supply operating power during sleep. 3. The wireless meter reading terminal device according to claim 1 or 2, wherein when the discharge voltage of the battery does not reach the range of the minimum operation maintaining voltage, a battery life advance notice message is transmitted. 4. The discharge voltage of the battery according to claim 1, wherein the discharge voltage of the battery can follow the temperature change of the outside air.
A wireless meter-reading terminal device, which is regularly detected at intervals of 3 hours or irregularly at any time. 5. The battery according to any one of claims 1 to 4, wherein the power supply for operating the communication function and the meter reading function and the power supply for detecting the discharge voltage of the battery are different from the battery. A wireless meter reading terminal device characterized by being used.