JPH0562876U - Battery replacement time notification device - Google Patents

Abstract

(57) [Abstract] [Purpose] It is to realize a battery replacement timing notifying device that can notify the battery replacement timing. [Configuration] Measuring resistor 11 for measuring load current
An AD converter 13 for converting a voltage value generated across the measuring resistor 11 into a digital signal, a clock generator 14 for generating a clock serving as a time reference, and an AD converter 1
A CPU for calculating the current consumption from the voltage value of the output of 3 and the time measured by the clock of the output of the clock generator 14.
15, a non-volatile memory 16 for storing the current consumption calculated by the CPU 15, and a display 6 for displaying the remaining usable time of the battery 1 or the battery replacement time.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a battery replacement timing notifying device that displays the remaining usable time of a battery.

[0002]

[Prior Art]

 Dry batteries or secondary batteries such as NiCd are often used as the main power source for handheld analyzers. When carrying out an analysis externally with this analyzer, if the life of the used battery, that is, the replacement time of the dry battery and the charging time of the secondary battery are not known, the power will be cut off at the site and analysis will not be possible. Occurrence occurs.

For this reason, conventionally, the advance notice of replacement or charging (hereinafter simply referred to as "replacement") is performed by monitoring the voltage of the main power supply and issuing a warning for replacement of the main power supply when the voltage drops below a certain voltage. It was out.

FIG. 2 shows a conventional battery replacement timing notifying device. In the figure, 1 is a battery that is a dry battery or a secondary battery that supplies power to the load 2, and 3 is a resistance for measuring the current battery voltage. Since the voltage is input from the connection point of the resistor 3 to the "-" terminal of the comparator 4, the input voltage to the "-" terminal of the comparator 4 is 1/2 of the voltage V _r across the load.

Reference numeral 5 is a reference voltage power supply input to the “+” terminal of the comparator 4, and a reference voltage for comparison with the input voltage from the resistor 3 input to the “−” terminal of the comparator 4. Output. This reference voltage is set to a voltage value indicating that the voltage of the battery 1 proportional to the output voltage V _r / 2 of the resistor 3 approaches the time when the battery 1 needs to be replaced.

The output of the comparator 4 is displayed on the display 6, and a warning is displayed when the output voltage of the resistor 3 is lower than the output voltage of the reference voltage power supply 5.

[0007]

[Problems to be solved by the device]

 This conventional battery replacement timing warning device only gives a warning when the voltage of the power supply 1 drops, and cannot determine the remaining usable time. In particular, since the discharge characteristics of the manganese dry battery and the discharge characteristics of the alkaline dry battery and the NiCd battery are different, it was not possible to determine the usable time by measuring the voltage of the battery.

Also, if the battery 1 is replaced after it becomes unusable, the analyzer will become unusable, so it is necessary to issue a warning for replacement early, and the battery 1 of the main power supply can be used. I could not use it to the limit.

The present invention has been made in view of the above points, and an object thereof is to realize a battery replacement timing notifying device capable of notifying the battery replacement timing in time.

[0010]

[Means for Solving the Problems]

 The present invention which solves the above-mentioned problems is provided with a resistance for measurement which is connected in series to a circuit in which a battery is connected to a load and outputs a dropped voltage based on a load current, and an AD converter which converts an input voltage into a digital signal. And a clock generator that generates a clock as a reference for measuring the circuit operating time, and a load current flowing in the circuit is calculated based on the measured voltage value from the AD converter, and the load current is input from the clock generator. A CPU for calculating an operating time based on a clock to obtain a current consumption, a non-volatile memory for storing the current consumption calculated by the CPU and accumulating the current consumption each time the circuit is operating, Remaining available time of the battery obtained from the current capacity of the battery previously input by the CPU, the cumulative current amount of use stored in the nonvolatile memory, and the load current expected thereafter It is characterized in being constituted by a display or replacement time and display for displaying time.

[0011]

[Action]

 When the circuit operates and a current flows from the battery to the load, the voltage generated in the measuring resistor connected in series to the circuit is converted into a digital signal by the AD converter and input to the CPU. The CPU calculates the current flowing from the battery from the resistance for measurement and the voltage value, accumulates the value of the current consumption amount obtained based on the clock from the clock generator, and stores it in the nonvolatile memory. From the current consumption stored in the non-volatile memory, the CPU calculates the remaining current of the battery and displays the remaining usage time on the display.

[0012]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram of an apparatus according to an embodiment of the present invention. In the figure, the same parts as those in FIG. 2 are designated by the same reference numerals. In the figure, 11 is a measuring resistor having a resistance value R for measuring a load current, and 13 is an AD converter which receives the voltage across the measuring resistor 11 and converts it into a digital signal.

Reference numeral 14 denotes a clock generator that generates a clock when the circuit is powered on and inputs the clock to the CPU 15 as a time measurement reference. Reference numeral 16 is a non-volatile memory that stores data of current consumption calculated from the operating time calculated by the CPU 15 and the input voltage.

Next, the operation of the apparatus configured as described above will be described. First, the principle of operation of this apparatus will be described. Cell 1, the circuit comprising a measuring resistor 11 of the load 2 and the resistance R, when the current flowing through the circuit I _R, the voltage across the measuring resistor 3 and _{V R, I R = V R} / R ...... ……………… (1) If the operating time of the circuit is T, the current flowing through the load in Eq. (1) and the current consumption up to that point can be calculated.

Generally, if the capacity QmAh of the battery 1 is known and the predicted current value i of the load to be used thereafter is known, the remaining time t during which the battery 1 can be supplied with current can be obtained by the following equation.

T = (Q−T × I _R ) / i (2) Next, the operation of the apparatus of the embodiment will be described. When the circuit is powered on and operated (switches such as a power switch are not shown), the CPU 15 starts counting time by counting clocks input from the clock generator 14. At the same time, the current consumption at each time is calculated from the voltage V _R across the measuring resistor 11 input from the AD converter 13, and the current consumption during operation of the circuit is stored in the non-volatile memory 16.

During circuit operation, the current consumption amount calculated at regular intervals or irregularly is stored in the nonvolatile memory 16 while being accumulated, and the total current consumption amount and the remaining current amount are calculated and predicted thereafter. By dividing the remaining current amount by the consumed current i, the remaining time of the battery 1 or the replacement time can be displayed.

When the battery 1 is a dry battery, the capacities are known, so the current capacities of various batteries are stored, and when the battery 1 is replaced, a suitable battery capacity is selected. In addition, a NiCd battery or the like whose current capacity changes can be dealt with by updating the actual current capacity each time.

As described above, according to the present invention, the remaining usable time of the battery can be known.

[0020]

[Effect of the device]

 As described in detail above, according to the present invention, it becomes possible to give an advance notice of the time to replace the battery, and it is possible to prevent the power-off state of the portable device from occurring in the field, so that there is no practical effect. large.

[Brief description of drawings]

FIG. 1 is a block diagram of an apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram of a conventional battery replacement timing notification device.

[Explanation of symbols]

 1 Battery 2 Load 6 Display 11 Measurement Resistance 13 AD Converter 14 Clock 15 CPU 16 Nonvolatile Memory

Claims (1)

[Scope of utility model registration request] 1. A measuring resistor (11) which is connected in series to a circuit in which a battery (1) is connected to a load (2) and outputs a dropped voltage based on a load current, and an input voltage is converted into a digital signal. AD converter (13), a clock generator (14) that generates a clock as a reference for measuring the circuit operating time, and a load current flowing in the circuit based on the measured voltage value from the AD converter (13). And the clock generator (1
4) CPU (15) for calculating the operating time based on the clock input from the clock to obtain the current consumption, and the current consumption calculated by the CPU (15) are stored to store the current consumption during the circuit operation. Non-volatile memory that accumulates
From the current capacity of the battery (1) pre-input by the CPU (15), the cumulative current amount of use stored in the non-volatile memory (16), and the load current expected thereafter. A battery replacement time advance notice device comprising a display (6) for displaying the obtained remaining usable time of the battery (1) or for displaying the replacement time.