JPH08194021A - Monitoring method and monitor of battery voltage - Google Patents

Abstract

PURPOSE: To constantly detect the lowering of battery voltage with simple constitution and to reduce consumption of a battery. CONSTITUTION: A warning value T1 and a lower limit value T2 of battery voltage in a stand-by state of a device, a warning value F1 and a lower limit value F2 in a small load working state A and a warning value D1 and a lower limit value D2 of the battery voltage in a large load working state B are memorized in a control part 21 of a wireless card reader device. Voltage of a battery 40 is compared with a standard voltage value memorized in the control part 21 by a comparing part 24. When the battery voltage becomes lower than the warning value T1 in the stand-by state, lower than the warning value F1 in the working state A and lower than the warning value D1 in the working state B, an electric power source indicating lamp 16a flashes and indicates it. When the battery voltage becomes lower than the lower limit value T2 in the stand-by state, lower than the lower limit value F2 in the working state A and lower than the lower limit value D2 in the working state B, a normal/abnormal indicating lamp 16d is lit on and indicates it.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for monitoring battery voltage used in battery-driven equipment and the like, and more particularly to improvement thereof.

[0002]

2. Description of the Related Art Conventionally, as a battery voltage monitoring device of this type, as disclosed in, for example, Japanese Patent Application Laid-Open No. 61-181227, when a power supply voltage drops below a predetermined first voltage, This is detected by the voltage detection circuit, the first flip-flop circuit is inverted by the detection result, and the warning display circuit is operated. Further, when the power supply voltage drops below the second voltage, which is lower than the first voltage, this is detected by the voltage detection circuit, the second flip-flop circuit is inverted based on the detection result, and the operation stop circuit is operated. I was doing. As described above, by setting the voltage reference values in two stages of the first voltage and the second voltage, it is possible to notify separately when the battery is exhausted and before the battery replacement warning, which is convenient. In addition, the voltage drop of the battery differs depending on the internal resistance, etc., and the more exhausted the battery, the greater the fluctuation of the voltage drop due to the size of the load.Therefore, set the reference voltage value separately when the power is off and when it is on. By doing so, it was possible to accurately know the exhaustion state of the battery.

Further, as another battery voltage monitoring device, for example, as disclosed in Japanese Utility Model Laid-Open No. 4-2140, a radio call receiver for driving a notifying unit by receiving a radio signal to issue a call notification. There is known a battery voltage drop detecting device in. This battery voltage drop detection device is insufficient to allow the maximum current consumption to flow to the receiver due to the activation of the current consumption means at the timing when the notification unit does not perform the call notification or when the notification unit does not call for a certain period in the past. The current is supplied from the battery, and at this time, the battery voltage monitoring means determines whether the voltage of the battery has dropped below a predetermined value. As a result, the battery voltage drop is accurately detected and the battery consumption associated with the detection is suppressed.

[0004]

However, according to the former, in order to monitor the battery voltage by providing a plurality of reference values,
Since a plurality of reference voltage sources, a voltage detection circuit, a flip-flop circuit, etc. are required, the circuit configuration becomes complicated and the cost becomes high. According to the latter,
Since the battery voltage drop is detected at a constant timing, if the timing is deviated, the voltage drop may be overlooked. Further, although the detection timing is taken into consideration, there is also a problem that the maximum load is applied to the battery when the battery voltage is detected, so that the consumption of the battery capacity cannot be avoided. The present invention is intended to solve the above-mentioned problems, and provides a battery voltage monitoring method and a monitoring device that can constantly detect a decrease in battery voltage with a simple configuration and that causes almost no battery consumption. With the goal.

[0005]

In order to achieve the above object, the structural feature of the invention according to claim 1 is that the detected value of the battery voltage is stored in advance in the storage means and the use limit of the battery voltage is stored. Value at least one lower limit reference value and at least one type of warning reference value higher than the lower limit reference value, and when the detected value of the battery voltage becomes less than or equal to the warning reference value, the display means continuously displays a warning The display means continuously displays the lower limit when the detected value of the battery voltage becomes less than or equal to the lower limit reference value.

[0006] Further, the constitutional feature of the invention according to claim 2 is that in the method for monitoring the battery voltage according to claim 1, when the detected value of the battery voltage becomes less than or equal to a warning reference value, the detected value is detected. Is compared with only the lower limit reference value, and when the detected value becomes less than or equal to the lower limit reference value, the comparison between the detected value and the lower limit reference value is stopped.

In addition, the constitutional feature of the invention according to claim 3 is that in the battery voltage monitoring method according to claim 1 or 2, the detected value of the battery voltage is equal to or lower than the lower limit reference value. At this time, the operation of the device driven by the battery voltage is stopped.

In addition, the structural features of the invention according to claim 4 are the battery voltage detecting means for detecting the battery voltage, at least one lower limit reference value which is the use limit value of the battery voltage, and the lower limit reference value. A voltage reference value storage means for storing at least one higher warning reference value, a detection value of the battery voltage detected by the battery voltage detection means, and a lower limit reference value and a warning reference value stored in the voltage reference value storage means. And compare
A voltage value comparison means that outputs a warning signal when the detected value falls below the warning reference value, and outputs a lower limit signal when the detected value falls below the lower limit reference value. And a display control means for receiving a warning signal from the voltage value comparison means to cause a warning display on the display means, and for receiving a lower limit signal from the voltage value comparison means to display a battery voltage lower limit on the display means. It has been established.

Further, the constitutional feature of the invention according to claim 5 is that in the battery voltage monitoring device according to claim 4, when the detected value is below the warning reference value in the voltage value comparison means. There is provided a voltage value comparison limiting means for comparing the detected value with only the lower limit reference value and stopping the comparison by the voltage value comparison means when the detected value becomes equal to or lower than the lower limit reference value.

Further, the constitutional feature of the invention according to claim 6 is that in the battery voltage monitoring apparatus according to claim 4 or 5, the battery voltage is received in response to a lower limit signal from the voltage comparison means. The operation stop control means for controlling the operation of the device driven by the voltage is provided.

[0011]

In the invention according to claim 1 configured as described above, since the warning is displayed in at least one step before the battery voltage reaches the lower limit value which is the usage limit of the battery, Exchange can be done with a margin.
Then, it is possible to reliably know that the lower limit value has been reached by the lower limit display. As a result, it is possible to appropriately deal with the exhaustion of the battery. In addition, considering that the voltage drop of the battery differs depending on the non-operating state and operating state of the load, it is possible to set two or more types of warning reference values and lower limit reference values. The battery voltage can be monitored. In addition, since the above-mentioned display is continuously performed, the battery consumption state is not overlooked. Furthermore, since at least one kind of lower limit reference value and at least one kind of warning reference value higher than the lower limit reference value are stored in the storage means, it is possible to monitor the exhausted state of the battery in a plurality of stages. It does not require a large number of circuit devices as in the past, and therefore the structure of the device is simplified.
The device cost can be reduced. Further, according to the present invention, since the battery voltage is detected and compared and judged, the battery is not subjected to an unnecessary load, and therefore the monitoring of the battery voltage causes almost no useless battery consumption. There is no.

Further, in the invention according to claim 2 configured as described above, in consideration of the fact that the battery voltage is greatly influenced by the magnitude of the load and the consumption state of the battery itself, when the battery voltage once becomes the reference value or less, Even if there is a possibility of becoming larger than the reference value after that, this is set as the range of the variation of the voltage value so that the reference value is not made the determination target of the battery voltage. As a result, in addition to the effect of the invention according to the first aspect, the user is not confused by the slight fluctuation of the battery voltage, and it is possible to deal with the exhausted state of the battery with a margin.

Further, in the invention according to claim 3 configured as described above, since the operation of the device driven by the battery voltage is stopped, the invention according to claim 1,
In addition to the effect of the invention according to 2, the operation of the device in an unstable state is excluded, so that malfunction of the device can be reliably prevented, and the effectiveness of monitoring the battery voltage is further enhanced.

Further, in the invention according to claim 4 configured as described above, the detected value of the battery voltage detected by the battery voltage detection means is equal to or less than the warning reference value stored in the voltage reference value storage means. In this case, the voltage value comparison means outputs a warning signal, and in response to this, the display means displays a warning under the control of the display control means. As a result, it is easily determined that the battery is almost exhausted. Further, when the detected value of the battery voltage becomes equal to or lower than the lower limit reference value stored in the voltage reference value storage means, the lower limit signal is output by the voltage value comparison means, and in response thereto, under the control of the display control means. The lower limit is displayed by the display means. As a result, it is easy to recognize that the battery is exhausted. Further, considering that the voltage drop of the battery differs depending on the non-operating state and operating state of the load, the voltage reference value storage means can store two or more kinds of warning reference values and lower limit reference values. It can be used to monitor the proper battery voltage according to the operating state of the battery. Further, since the display by the display means is continuously performed, the user does not overlook the exhaustion state of the battery, so that the exhaustion state of the battery can be appropriately dealt with. Further, since at least one kind of lower limit reference value and at least one kind of warning reference value can be stored in a single storage means, it is possible to monitor the battery exhaustion state at a plurality of stages by using many conventional methods. Therefore, the configuration of the monitoring device is simplified and the cost of the monitoring device can be reduced. Further, according to the present invention, since the battery voltage is detected and compared and judged, the battery is not subjected to an unnecessary load, and therefore the monitoring of the battery voltage causes almost no useless battery consumption. There is no.

Further, in the invention according to claim 5 configured as described above, in consideration of the fact that the battery voltage is greatly influenced by the magnitude of the load and the consumption state of the battery itself, the voltage value comparison limiting means is used to set the voltage value. The action of the comparison means is limited, and when the detected value becomes equal to or less than the reference value, the reference value is not made to be compared with the detected value. As a result, in addition to the effect of the invention according to claim 4, the user is not confused by a slight fluctuation of the battery voltage around the reference value, and the battery exhaustion state can be dealt with with a margin.

In the invention according to claim 6 configured as described above, when the lower limit signal is output from the voltage value comparison means, the operation of the device driven by the battery voltage is controlled by the operation stop control means. To stop. As a result, in addition to the effects of the inventions according to claims 4 and 5, since the operation of the device in an unstable state is excluded, it is possible to reliably prevent malfunction of the device, and battery voltage. The effectiveness of surveillance will be further enhanced.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIGS. 1 and 2 show a battery-powered wireless card reader device equipped with a battery voltage monitoring device according to the embodiment and its circuit configuration. Is schematically shown. The wireless card reader device is provided in a remote place of, for example, about 100 m and performs data communication with a base station receiving device that outputs received data to a host computer. It has the advantage of being able to perform layouts without any restrictions.

The wireless card reader device 10 has a length of 134.
A card reading unit 12 having a rectangular parallelepiped plastic body 11 mm × width 84 mm × thickness 46 mm and having a slit 12a for inserting a card is provided in the body 11.
Is provided. Also, on the front of the main body 11, a power switch 1
3, a numeric keypad 14 for inputting numbers, and a function key (hereinafter referred to as f key) 15 are provided. The f key 15 is composed of four keys f1 to f4. By turning on the f1 key 15a, the card reading unit 12
Is ready to be read. By turning on the f2 key 15b, the ten keys 14 can be input. f3
By turning on the key 15c, a bar code reader (not shown) attached to the main body 11 can be input. The f4 key 15d also has the functions of the f1 to f3 keys. Then, on the upper side of the front surface of the main body, a power supply display lamp 16a that displays ON / OFF of the power switch 13, a data input enable display lamp 16b that displays whether data can be input, and a wireless communication display lamp that displays that wireless communication is in progress. 16c, reading normal / abnormality display lamp 16d that lights up when the battery voltage reading is abnormal
(Hereinafter referred to as normal / abnormal display lamp) and f key 15
There are provided four f-key display lamps 16e for displaying ON / OFF of.

Next, the electric circuit configuration of the wireless card reader device 10 will be described. Wireless card reader device 10
Is provided with a microcomputer 20. The microcomputer 20 processes various input signals and stores necessary information such as a reference voltage value, and an A / D converter for digitally converting a battery voltage input. 22, a calculator 23 for averaging the digital signals, and a comparator 24 for comparing the averaged digital signals with a reference voltage value stored in the controller 21 and outputting a comparison result. There is.

The control unit 21 includes a wireless card reader device 10
Warning value T1 and lower limit value T2 of the battery voltage in the standby state (minimum load state) such as when the power is turned on, and the warning value F1 of the battery voltage in the operating state A (the state where the load is small) in the function mode of the wireless card reader device. And a lower limit value F2, and a warning value D1 and a lower limit value D2 of the battery voltage in the operating state B (state where the load is large) such as wireless communication are stored. Here, the lower limit value indicates the voltage value at which the battery voltage has dropped until it interferes with the normal operation of the wireless card reader device, and the warning value is slightly larger than the lower limit value, and the battery voltage is close to the lower limit value. It is a value provided to notify the. Then, the standby state when the power of the wireless card reader device 10 is turned on and the operating state A with the small load described above.
And the warning value and the lower limit value are separately provided for the operation state B where the load is large, because the voltage drop of the battery is
The difference in the internal resistance of the battery, and the more exhausted the battery, the greater the variation in the voltage drop depending on the size of the load. Therefore, in the judgment of only one of the standby state, the operating state A and the operating state B, the battery is exhausted. This is because it may not be possible to know the state accurately. Then, when the power switch 13 is turned on, the microcomputer 20 continues to execute the "battery voltage monitoring control program" corresponding to the flowcharts shown in FIGS.

On the input side of the control unit 21, the power switch 13, the ten key 14 and the f key 15 (15a to 15) are provided.
d) is connected. The card reading unit 12 is connected to the input side of the control unit 21. Control unit 2
On the output side of 1, a signal corresponding to the input content from the card reading unit 12 is wirelessly transmitted to the base station receiving device, and a radio signal from the base station receiving device is received and a response is made with the control unit 21. The transmitter / receiver 30 is connected. Control unit 21
The output side of the transmitter / receiver 3 is connected to the constant voltage circuit 41 described later.
A voltage supply switch 31 for supplying and shutting off power to 0 and a voltage supply switch 32 for supplying and shutting off power to the card reading unit 12 from the constant voltage circuit 41 are connected. On the output side of the control unit 21, the power supply display lamp 16a, the data input enable display lamp 16b, the wireless communication in-progress display lamp 16c, and the normal / abnormal display lamp 16d.
Also, the f key display lamp 16e is connected.

A battery 40 having a voltage of 6v is used as a power source for driving the electric circuit. On the output side of the battery 40, a switch 13 that interlocks with the power switch 13 is provided.
a is connected. A constant voltage circuit 41 is provided via the switch 13a, and the output side of the constant voltage circuit 41 is connected to the voltage supply switches 31 and 32 and also to the microcomputer 20. The resistors r1 and r2 are grounded between the switch 13a and the constant voltage circuit 41, and the input line is connected to the A / D converter 22 from between both resistors, and the battery voltage is divided to perform A / D conversion. It is adapted to be input to the device 22.

Next, the operation of the embodiment configured as described above will be described. By turning on the power switch 13, the wireless card reader device 10 enters a standby state. Then, the microcomputer 20 starts the execution of the “battery voltage monitoring control program” at step 50 shown in FIG. 3, and outputs a power supply display signal at step 51. In response to this, the power supply display lamp 16a starts lighting display.
Next, in step 52, the warning value T1 and the lower limit value T2 of the battery voltage stored in the control unit 21 in the standby state when the power of the wireless card reader device 10 is turned on, and the warning value F1 of the battery voltage in the operating state A and The lower limit value F2, the battery voltage warning value D1 and the lower limit value D2 in the operating state B are read into the comparison unit 24. Next, in step 53,
The battery voltage detection value M, which is digitally converted by the A / D converter 22 and averaged by the calculation unit 23, is input to the comparison unit 24. Hereinafter, when the wireless card reader device 10 is in the standby state, that is, when the f key 15 is not turned on and is not in the operating state,
The monitoring control of the battery voltage in three states from the standby state to the operating state A in which the load in the function mode is small and to the operating state B in which the load is large, such as during wireless communication, will be sequentially described.

(1) Monitoring control of battery voltage in the standby state of the wireless card reader device 10 The program is moved to step 55 based on "NO" in step 54, and the battery voltage detection value M and the warning value T1 are set. The comparison starts. When the detected value M is still larger than the warning value T1, the program is moved to step 57 based on the judgment of "NO" in step 56 and it is judged whether or not the f key 15 is turned on. Since the f key 15 is not operated here, the program is returned to step 56 based on the determination of "NO", and the processes of steps 56 and 57 are repeated. Then, when the detected voltage value M becomes less than the warning value T1 due to the exhaustion of the battery, the program proceeds to step 58 based on the determination of "YES" at step 56.
Then, the control unit 21 outputs a battery voltage drop warning signal. In response to this, the power supply display lamp 16a starts blinking display indicating a warning of voltage drop. As a result, the user of the wireless card reader device can know that the replacement of the battery is approaching.

Following the blinking display of the power display lamp 16a,
In step 59, the comparison target of the battery voltage detection value M is switched from the warning value T1 to the lower limit value T2. That is, even if the detected value M becomes larger than the warning value T1 thereafter, the comparison with the warning value T1 is not performed again. As a result, when the detected value M is unstable, the display content is prevented from changing, and the user's judgment is prevented from being confused. Then, when the detected value M is still larger than the lower limit value T2, the program is moved to step 61 based on the judgment of "NO", and it is judged whether or not the f key 15 is turned on. Since the f key 15 is not operated here, the program is returned to step 60 based on the determination of "NO", and the processing of steps 60 and 61 is repeated thereafter.

After that, the battery consumption further advances and the detected value M
Is less than or equal to the lower limit value T2, in step 60, "YE
Based on the determination of "S", the program is moved to step 62, and the control unit 21 outputs the lower limit display signal. In response to this, the normal / abnormal display lamp 16d performs a lighting display indicating that the battery voltage has become equal to or lower than the lower limit value. This allows the user of the wireless card reader device to know that the battery must be replaced. Then, in step 63, the microcomputer 20 ends the execution of the program.

(2) Operation state A in which the wireless card reader device is in a standby state and the load in the function mode is small
If the battery voltage is still low and the battery voltage is higher than the warning value T1, for example, if the f1 key 15a is turned on and the card reading unit 12 is set to the card readable state,
Based on the determination of "YES" in step 54 or step 57, the program is moved to step 70 shown in FIG. 4, and the f1 key-on display signal is output. In response to this, the data input enable display lamp 16b starts lighting.
Then, in step 71, the control unit 21 outputs a switch-on signal to turn on the voltage supply switch 32. As a result, the card reading unit 12 becomes operable.

Next, at step 72, the comparison between the battery voltage detection value M and the warning value F1 in the operating state A is started. When the detected value M is still larger than the warning value F1, the program is moved to step 74 based on the judgment of "NO" in step 73 and whether the card C is read by the card reading unit 12 or not. To be judged. Here, the card C is not read, so "NO".
Then, the program is moved to step 75,
It is determined whether the f1 key 15a has been turned off. Here, the f1 key 15a is not turned off, so "NO"
The program is returned to step 73 on the basis of the determination that the above, and the processing of steps 73 to 75 is repeated.

When the detected voltage value M becomes less than the warning value F1 due to the exhaustion of the battery, "YES" is determined in the step 73.
Then, the program is moved to step 76,
A warning signal of low battery voltage is output from the control unit 21.
In response to this, the power supply display lamp 16a starts blinking display indicating a warning of voltage drop. As a result, the user of the wireless card reader device can know that the replacement of the battery is approaching.

After the blinking display of the power supply display lamp 16a is performed, the comparison target of the battery voltage detection value M is switched from the warning value F1 to the lower limit value F2 in step 77, and the detection value M is thereafter and the warning value F1. Even if it becomes larger, the warning value F
The comparison with 1 is prevented. Then, when the detected value M is still larger than the lower limit value F2, the program is moved to step 79 based on the judgment of "NO" in step 78, and the card reading section 12 causes the card C to read.
Is read or not is determined. here,
Since the card C is not read, the program moves to step 80 based on the judgment of "NO" to judge whether or not the f1 key 15a is turned off. f1 key 1
Since 5a is not turned off, the program is returned to step 78 based on the judgment of "NO".
The processing of 80 is repeated.

When the detected voltage value M becomes lower than the lower limit value F2 due to exhaustion of the battery, "YES" is determined in the step 78.
Then, the program is moved to step 81,
The lower limit display signal is output from the control unit 21. In response to this, the normal / abnormal display lamp 16d starts lighting display indicating that the battery voltage has become equal to or lower than the lower limit value. This allows the user of the wireless card reader device to know that the battery must be replaced. Then, in step 82, the control unit 21 outputs the OFF signal of the switch 32, and thereafter, even if the f key 15 is turned on, the card reading unit 12 is prevented from operating.
At 3, the execution of the program ends.

Next, in the standby state, the battery is exhausted and the battery voltage becomes smaller than the warning value T1 and the warning is displayed by the power supply display lamp 16a. The case of setting to A will be described. At this time,
Based on the determination of "YES" in step 61 shown in FIG. 5, the program is moved to step 90 shown in FIG. 5, and the f1 key-on display signal is output. In response to this, the data input enable display lamp 16b is turned on. And step 9
At 1, the control unit 21 outputs a switch-on signal,
The voltage supply switch 32 is turned on. As a result, the card reading unit 12 becomes operable.

Next, at step 92, the comparison between the battery voltage detection value M and the lower limit value F2 in the operating state A is started. If the detected value M is still larger than the lower limit F2, the program is sequentially moved to steps 94 and 95 based on the judgment of "NO" in step 93, and the card C is read by the card reading unit 12. Whether or not and f
1 It is determined whether the key 15a has been turned off. Here, the card C is not read, and the f1 key 1
5a is not turned off, so in steps 94 and 95, "N
Based on the determination of "O", the program is returned to step 93, and the processes of steps 93 to 95 are repeated.

When the detected voltage value M becomes lower than the lower limit value F2 due to exhaustion of the battery, "YES" is determined in the step 93.
If so, the program moves to step 96,
A lower limit display signal of the battery voltage is output from the control unit 21.
In response to this, the normal / abnormal display lamp 16d starts lighting display indicating that the battery voltage has become equal to or lower than the lower limit value.
This allows the user of the wireless card reader device to know that the battery must be replaced. Then, in step 97, the control unit 21 outputs the off signal of the switch 32, and thereafter, even if the f key 15 is turned on, the card reading unit 12 is not operated. Further, in step 98, the microcomputer 20 ends the execution of the program.

(3) Operation state A of the wireless card reader device
The card voltage is monitored when the card is read in the operating state B, such as during wireless communication, and the battery voltage is greater than the warning value F1 in the operating state A. C is slit 1
When the card is inserted into the card 2a and read by the card reader 12, the program is transferred to step 100 shown in FIG. 6 based on the judgment of "YES" in step 74, and f1
A key-off display signal is output. In response to this, the f key display lamp 16e is turned off. And step 101
At the control section 21, the off signal of the switch 32 is output, the voltage supply switch 32 is turned off, and step 102
The ON signal of the switch 31 is output at and the voltage supply switch 31 is turned on. As a result, the transmission / reception unit 30 becomes operable, and a transmission command is sent from the control unit 21 to the transmission / reception unit 3
By outputting 0, wireless communication is started. At the same time, in step 103, the control unit 21 outputs a wireless communication ON display signal, and in response thereto, the wireless communication display lamp 16c starts lighting.

Next, at step 104, the comparison between the battery voltage detection value M and the warning value D1 in the operating state B is started. When the detected value M is still larger than the warning value D1, the program is moved to step 106 based on the judgment of "NO" in step 105, and it is judged whether or not the operation state B, that is, the wireless communication is ended. . When the wireless communication is not completed yet, the program is returned to step 105 based on the determination of “NO”, and the following step 1
The processing of 05 and 106 is repeated. Then, when the wireless communication is completed, the program is moved to step 107 based on the determination of “YES” in step 106, and the control unit 2
The wireless communication OFF display signal is output by 1, and the wireless communication display lamp 16c is turned off in response to this. further,
In step 108, the off signal of the switch 31 is output, and the voltage supply switch 31 is turned off. Thereafter, the program is returned to step 55 shown in FIG. 3, and the battery voltage monitoring control in the standby state is performed as described above.

When the detected voltage value M becomes less than the warning value D1 due to exhaustion of the battery during wireless communication, the program proceeds to step 10 based on the judgment of "YES" at step 105.
9, the battery voltage drop warning display signal is sent to the control unit 21.
Output from In response to this, the power display lamp 16a
Starts the blinking display that shows the warning of the voltage drop. As a result, the user of the wireless card reader device can know that the replacement of the battery is approaching.

After the blinking display of the power source display lamp 16a is performed, the comparison target of the battery voltage detection value M is switched from the warning value D1 to the lower limit value D2 in step 110, and the detection value M is detected.
After that, even if it becomes larger than the warning value D1, the comparison with the warning value D1 is not performed again. Then, when the detected value M is still larger than the lower limit value D2, the program is moved to step 112 based on the judgment of "NO" in step 111, and it is judged whether or not the wireless communication is completed. If the wireless communication is not yet completed, the program proceeds to step 11 based on the judgment of "NO".
The value is returned to 1, and the processing of steps 111 and 112 is repeated. Then, when the wireless communication ends, step 1
Based on the determination of "YES" at 12, the program is moved to step 113, the control unit 21 outputs the wireless communication OFF display signal, and the wireless communication display lamp 16c is turned off accordingly. Further, in step 114, the off signal of the switch 31 is output to turn off the voltage supply switch 31. Thereafter, the program is returned to step 59, and the battery voltage monitoring control in the standby state is performed as described above.

When the voltage detection value M becomes lower than the lower limit value D2 due to exhaustion of the battery during wireless communication, in step 111, "Y"
Based on the determination of “ES”, the program is moved to step 115, and the lower limit display signal is output from the control unit 21. In response to this, the normal / abnormal display lamp 16d starts lighting display indicating that the battery voltage has become equal to or lower than the lower limit value. This allows the user of the wireless card reader device to know that the battery must be replaced. Then, in step 117, the control unit 21 causes the switch 31 to switch.
Is output, the voltage supply switch 31 is turned off in response to this, and the subsequent wireless communication is interrupted. Further, in step 118, the microcomputer 20 finishes executing the program.

Next, in the operating state A, the battery C is depleted, the battery voltage becomes smaller than the warning value F1, and the power indicator lamp 16a displays a warning message.
Is inserted into the slit 12a and read by the card reading unit 12, the program is moved to step 120 shown in FIG. 7 based on the judgment of "YES" in step 79 or 94, and the f1 key-off display signal is sent. Is output. In response to this, the data input enable display lamp 16b is turned off. Then, in step 121, the control unit 21 outputs the off signal of the switch 32 to turn off the voltage supply switch 32. Further, in step 122, the control unit 21 outputs the ON signal of the switch 31 to turn on the voltage supply switch 31. As a result, the transmission / reception unit 30 becomes operable, and a transmission command is output from the control unit 21 to the transmission / reception unit 30 to start wireless communication. At the same time, in step 123, the wireless communication ON display signal is output from the control unit 21, and the wireless communication display lamp 16c starts lighting in response thereto.

Next, at step 124, the comparison between the battery voltage detection value M and the lower limit value D2 in the operating state B is started. When the detected value M is still larger than the warning value D2, the program is moved to step 126 based on the judgment of "NO" in step 125, and it is judged whether or not the wireless communication is completed. When the wireless communication is not yet completed, the program is returned to step 125 based on the determination of "NO", and the processes of steps 125 and 126 are repeated. Then, when the wireless communication is completed, the program is moved to step 127 based on the determination of “YES” in step 126, the control unit 21 outputs the wireless communication off display signal, and accordingly the wireless communication is in progress. The display lamp 16c goes out. Further, in step 128, the OFF signal of the switch 31 is output to turn off the voltage supply switch 31. Then the program goes to step 5
Then, the monitoring control of the battery voltage in the standby state is performed as described above.

When the detected voltage value M becomes lower than the lower limit value D2 due to exhaustion of the battery during wireless communication, the program proceeds to step 12 based on the judgment of "YES" at step 125.
Then, the control unit 21 outputs the battery voltage lower limit display signal. In response to this, the normal / abnormal display lamp 16d
Starts the lighting display indicating that the battery voltage has become equal to or lower than the lower limit value. This allows the user of the wireless card reader device to know that the battery must be replaced. Then, in step 130, the wireless communication OFF display signal is output, and the wireless communication display lamp 16c is turned off in response to this. Further, in step 131, the control unit 21 outputs the off signal of the switch 31, and the operation of the transmission / reception unit 30 is stopped. Then, in step 132, the microcomputer 20 ends the execution of the program.

In the operating state A and when the battery voltage is higher than the warning value F1, when the f1 key 15a is turned off before reading the card, it is determined as "YES" in step 75 shown in FIG. Then, the program is moved to step 140, the off signal of the switch 32 is output, and the voltage supply switch 32 is turned off. Further, in step 141, the f-key off display signal is output, and in response to this, the f-key display lamp 16e is turned off.
Then, the program is returned to step 55, and the monitor control of the battery voltage in the standby state is performed as described above.

When the battery voltage is higher than the lower limit value F2 in the above operating state A, f1 is read before reading the card.
When the key 15a is turned off, the program is moved to step 142 (or 150) based on the determination of "YES" in step 80 (or 95), and the switch 3
The OFF signal of 2 is output to turn off the voltage supply switch 32. Further, in step 143 (or 151), the f key off display signal is output, and in response to this, the f key display lamp 16e is turned off. Thereafter, the program is returned to step 59, and the battery voltage monitoring control in the standby state is performed as described above.

As described above, according to the above embodiment, the warning is displayed before the battery voltage reaches the lower limit value which is the limit of use of the battery, so that the battery can be replaced with a margin. Then, it is possible to reliably know that the voltage has reached the lower limit value by the lower limit display. In addition, the warning value and the lower limit value are the standby state in which the load of the wireless card reader device with different battery voltage fluctuations is extremely small, the operation state A in which the load is small due to the function mode, and the operation state B in which the load is large such as during wireless communication. Since it is provided in three stages, it is possible to accurately grasp the consumption state of the battery voltage for each state. Since the above display is continuously performed after the power switch 13 is turned on, the battery exhausted state is not overlooked. Further, the above-mentioned 6 types of reference values can be processed by a single circuit configuration, and a circuit device is not required for each reference value. Therefore, the circuit configuration can be simplified and the device cost can be reduced. be able to.

Further, according to the above-mentioned embodiment, the battery voltage is detected, and this is digitally processed to be compared with various reference values, so that no unnecessary load is given to the battery, and therefore the battery is continuously operated. Even if the battery voltage is monitored, unnecessary battery consumption is hardly caused. Further, in the above embodiment, considering that the battery voltage is greatly affected by the magnitude of the load and the exhaustion state of the battery itself, when it becomes less than or equal to the warning value or the lower limit value, it then becomes greater than the warning value or the lower limit value. Even if there is a possibility, this is set as the range of the variation of the voltage value, and this is not set as the determination target of the battery voltage. Therefore, the user is not confused by such a slight fluctuation of the battery voltage, and it is possible to deal with the exhausted state of the battery with a sufficient margin. Further, in the present embodiment, when the battery voltage becomes lower than the lower limit value, the operation of the wireless card reader device is stopped thereafter, so that the operation of the wireless card reader device in an unstable state is eliminated. Therefore, the malfunction of the device can be surely prevented, and the effectiveness of the battery voltage monitoring can be further enhanced.

In each of the above embodiments, the wireless card reader device has three states, that is, the standby state, the operating state A and the operating state B.
Although the warning value and the lower limit value are set separately for each step, the warning value and the lower limit value may be set for two steps or four or more steps. Further, if necessary, a single warning value and a lower limit value may be set without dividing the standby state and the operating state. Further, in the above embodiment, the operation of the wireless card reader device is stopped when the voltage becomes equal to or lower than the lower limit value, but this function may be omitted if necessary. In the above embodiment, only the f1 key is used as the f key, but the f2 to f4 keys can be selected and used as needed. Further, the shape and the like of each part of the wireless card reader device shown in the above embodiment is not limited to the one having the above configuration, and can be appropriately changed as necessary.

In each of the above embodiments, the case where the battery voltage monitoring device according to the present invention is applied to a battery-driven wireless card reader device has been described, but in addition, a cordless telephone, a pager, etc. Can be used for the battery-powered wireless device. Further, the present invention can be applied to the battery voltage monitoring of portable battery-driven electric equipment such as a cassette recorder with a radio.

[Brief description of drawings]

FIG. 1 is a perspective view schematically showing a wireless card reader device according to an embodiment of the present invention.

FIG. 2 is a circuit diagram schematically showing an electric circuit configuration of the wireless card reader device.

3 is a part of a flowchart of a "battery voltage monitoring control program" executed by the microcomputer of FIG.

FIG. 4 is a part of a flowchart of the “battery voltage monitoring control program”.

FIG. 5 is a part of a flowchart of the same “battery voltage monitoring control program”.

FIG. 6 is a part of a flowchart of the “battery voltage monitoring control program”.

FIG. 7 is a part of a flowchart of the “battery voltage monitoring control program”.

[Explanation of symbols]

10 ... Wireless card reader device, 11 ... Main body, 12 ... Card reading unit, 12a ... Slit, 13 ... Power switch, 14 ... Numeric keypad, 15 ... F key, 16a ... Power supply display lamp, 16b ... Data input enable display lamp, 16c ... indicating wireless communication, 16d ... normal / abnormal display lamp,
16e ... F key display lamp, 20 ... Microcomputer, 21 ... Control part, 22 ... A / D converter, 23 ... Arithmetic part, 24 ... Comparison part, 30 ... Transceiver part, 31, 32 ... Voltage supply switch, 40 ... Battery, 41 ... Constant voltage circuit.

Claims (6)

[Claims] 1. The detected value of the battery voltage is at least one lower limit reference value which is a use limit value of the battery voltage stored in advance in the storage means, and at least one warning reference value higher than the lower limit reference value. In comparison, when the detected value of the battery voltage becomes less than or equal to the warning reference value, the display means continuously displays a warning, and when the detected value of the battery voltage becomes less than or equal to the lower limit reference value, by the display means. A battery voltage monitoring method characterized in that the lower limit is displayed continuously. 2. The battery voltage monitoring method according to claim 1, wherein when the detected value of the battery voltage becomes equal to or lower than the warning reference value, the detected value is compared with only the lower limit reference value, A method for monitoring a battery voltage, wherein when the detected value becomes equal to or lower than the lower limit reference value, the comparison between the detected value and the lower limit reference value is stopped. 3. The battery voltage monitoring method according to claim 1, wherein when the detected value of the battery voltage is equal to or lower than the lower limit reference value, the operation of the device driven by the battery voltage is performed. A method for monitoring battery voltage, which is characterized in that it is stopped. 4. A battery voltage detecting means for detecting a battery voltage, at least one lower limit reference value which is a use limit value of the battery voltage, and at least one warning reference value higher than the lower limit reference value are stored. Voltage reference value storage means to compare the detection value of the battery voltage detected by the battery voltage detection means and the lower limit reference value and the warning reference value stored in the voltage reference value storage means, the same detection value is the same. A warning signal is output when the value falls below the warning reference value, and a lower limit signal is output when the detection value falls below the lower limit reference value. And a display unit for displaying the battery voltage lower limit signal from the voltage value comparison unit, and a lower limit signal from the voltage value comparison unit to display the battery voltage lower limit. Display control hand Monitor the battery voltage, characterized in that a and. 5. The battery voltage monitoring device according to claim 4, wherein when the detected value is equal to or lower than the warning reference value, the detected value is set to the lower limit reference value only. A battery voltage monitoring device characterized in that a voltage value comparison limiting means is provided for stopping the comparison by the same voltage value comparing means when the values are compared and the detected value becomes equal to or lower than the lower limit reference value. 6. The battery voltage monitoring device according to claim 4 or 5, wherein the lower limit signal from the voltage value comparison means is received to stop the operation of the device driven by the battery voltage. An apparatus for monitoring battery voltage, which is provided with an operation stop control means for controlling.