JP3671255B2 - Power monitoring device - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a power supply monitoring device that is mounted on a battery-driven electronic device such as a PDA (Personal Digital Assistant) and monitors the power supply state.
[0002]
[Prior art]
Conventionally, a battery-powered electronic device such as a PDA detects the terminal voltage of the battery power supply, displays a symbol indicating whether the voltage level is operable, or displays a message prompting battery replacement or charging. Power supply monitoring function is provided.
[0003]
That is, a power supply monitoring function in a conventional electronic device generally performs the symbol display or message display when the voltage level of the battery power supply reaches a predetermined value or less.
[0004]
[Problems to be solved by the invention]
However, electronic devices represented by PDAs have various functions that require relatively large power consumption, such as communication functions with external devices and data access functions with memory cards. Even when the battery power supply voltage drop is not warned, if the battery capacity is consumed to some extent, when the communication process or data access process is actually executed, the power supply voltage will drop significantly and become inoperable. May reach up to.
[0005]
In this case, there is a problem that the processing is interrupted or an operation error is caused even though the warning symbol or message regarding the battery power source is not displayed.
The present invention has been made in view of the above problems, and an object of the present invention is to provide a power supply monitoring apparatus capable of performing highly reliable power supply monitoring in consideration of a voltage drop due to an actual operation.
[0006]
[Means for Solving the Problems]
The present invention specifies a resistance group, a switch group for controlling a combination of the resistance group, and an open / closed state of the switch group in a power supply monitoring apparatus provided in an electronic device having a plurality of types of communication functions and driven by a battery A pseudo load circuit composed of a latch circuit that latches pseudo load data, and a pseudo that designates an open / close state of a switch group of the pseudo load circuit so as to set a load corresponding to each communication operation for each of the plurality of types of communication functions. Before executing the communication function of the electronic load and the pseudo load data storage means for storing the load data, the corresponding pseudo load data is read from the pseudo load data storage means and latched in the latch circuit of the pseudo load circuit. , the load corresponding to the communication operation executed generated in the dummy load circuit, and a pseudo load setting means provided to the battery, the pseudo load setting Voltage measuring means for measuring the output voltage of the battery in a state where the load set by the stage is applied to the battery, and an abnormality notifying means for notifying the abnormality of the battery based on a measurement result by the voltage measuring means. It is characterized by having.
[0012]
【Example】
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a configuration of an electronic circuit of a PDA device equipped with a power supply monitoring device.
[0013]
This PDA apparatus includes a CPU 11.
The CPU 11 starts a system program stored in advance in the ROM 13 in accordance with a key operation signal from the key input unit 12 and executes operation control of each part of the circuit. The CPU 11 is connected to the CPU 11 via a system bus BUS. In addition to the key input unit 12 and the ROM 13, a RAM 14, an IR interface 15, an RS-232C interface 16, and a PCMCIA card interface 17 are connected, and a transmission / reception circuit 18 is connected to the IR interface 15.
[0014]
The CPU 11 is connected to a power supply monitoring unit 19 and a pseudo load level setting ROM 20 via the system bus BUS and a liquid crystal display unit 21.
[0015]
The key input unit 12 is operated to input notebook data such as address data, telephone number data, and schedule data when functioning as an electronic notebook, or a numerical value or operator when functioning as a calculator. In addition to input keys for characters, numbers, symbols, kana / kanji conversion keys, selection / execution keys, etc., which are used to input characters, IR communication mode for infrared data communication with external devices is set. The “IR” key 12a operated when performing the communication, the “232C” key 12b operated when setting the 232C communication mode for performing data communication with the external device according to the RS-232C standard, and the PCMCIA card Various function keys such as a “card” key 12c operated when setting a card access mode for performing data access are provided. That.
[0016]
The RAM 14 temporarily stores, for example, a notebook data register in which notebook data such as address data and schedule data input and displayed in response to a key operation in the key input unit 12 is registered, and input / output data accompanying the processing of the CPU 11. A work register is provided.
[0017]
In the I / R interface 15, input of infrared communication data to be transmitted / received to / from an external device via the transmission / reception circuit 18 in the state where the IR communication mode is set according to the operation of the “IR” key 12a. Output control is performed.
[0018]
In the RS-232C interface 16, input / output control of data transmitted / received to / from an external device via a cable is performed in a state where the 232C communication mode is set according to the operation of the “232C” key 12 b. .
[0019]
The PCMCIA card interface 17 performs input / output control of data accessed with the PCMCIA card in a state where the card access mode is set according to the operation of the “card” key 12c.
[0020]
The power supply monitoring unit 19 monitors whether the voltage level of the battery power supply can withstand the load associated with the subsequent processing operation when the PDA device is turned on and when various operation modes are set. Therefore, the power supply monitoring process centered on the power supply monitoring unit 19 is executed based on the pseudo load setting data corresponding to various operation modes stored in advance in the pseudo load level setting ROM 20 and the necessary minimum voltage data. .
[0021]
FIG. 2 is a circuit diagram showing an internal configuration of the power monitoring unit 19 provided in the PDA device.
The power monitoring unit 19 includes a battery power source 22, and each circuit unit of the PDA device is driven by the battery voltage from the battery power source 22.
[0022]
The output voltage of the battery power source 22 is constantly measured as 8-bit digital data by the A / D converter 23, and the battery voltage measurement data in the A / D converter 23 is measured by the measurement control signal a from the CPU 11. Accordingly, the data is taken into the CPU 11 via the system bus BUS.
[0023]
The battery power source 22 in the power source monitoring unit 19 is connected to a pseudo load circuit RA including seven resistors R1 to R7 and eight switches A1 to A8.
This pseudo load circuit RA combines resistors R1 to R4 in parallel with the battery power source 22 and resistors R4 to R7 in series, and each resistor is bypassed by selecting / ON by turning off the corresponding switches A1 to A7. The pseudo load circuit RA for the battery power source 22 is connected when the switch A8 is ON and disconnected when it is OFF.
[0024]
The switches A1 to A8 are turned on / off according to load control signals C1 to C8 corresponding to the pseudo load data latched by the 8-bit latch circuit 24. The 8-bit latch circuit 24 has a key input. The pseudo load data corresponding to the operation mode selected by the operation is selectively read from the pseudo load level setting ROM 20 and latched in synchronization with the latch clock b from the CPU 11.
[0025]
In the pseudo load level setting ROM 20, each of the pseudo load circuits RA for setting a pseudo load corresponding to each of the normal operation after power-on and the operations of the IR communication mode, the 232C communication mode, and the card access mode is provided. Corresponding 8-bit pseudo load data is stored in advance.
[0026]
The pseudo load level setting ROM 20 stores necessary minimum voltage data V1 to V4 corresponding to the normal operation after the power is turned on and the operations of the IR communication mode, the 232C communication mode, and the card access mode.
[0027]
Next, the power supply monitoring operation in the PDA device having the above configuration will be described.
FIG. 3 is a flowchart showing power supply monitoring processing in the PDA apparatus.
That is, first, when the power of the PDA device is turned on, the 8-bit pseudo load data “100001111” corresponding to the normal operation after the power is turned on, which is stored in advance in the pseudo load level setting ROM 20, is read. The 8-bit latch circuit 24 (see FIG. 2) is latched and set in synchronization with the latch clock b from the CPU 11 (step S1).
[0028]
Then, the switches A1, A5, A6, A7, and A8 in the pseudo load circuit RA are turned on in accordance with the load control signals C1 to C8 corresponding to the pseudo load data “10001111” latched in the 8-bit latch circuit, and the switch A2, A3, and A4 are turned off. As a result, the battery power supply 22 is connected to the resistors R2, R3, and R4 of the pseudo load circuit RA in parallel. The load state is set.
[0029]
Thus, the output voltage of the battery power source 22 measured by the A / D converter 23 is set in a state where a pseudo load corresponding to the normal operation after the power is turned on is set by the pseudo load circuit RA for the battery power source 22. The measurement control signal a from the CPU 11 takes the battery voltage measurement data into the CPU 11 and compares it with the necessary minimum voltage data V1 corresponding to the normal operation after the power is turned on and stored in the pseudo load level setting ROM 20 in advance. (Step S2).
[0030]
That is, “power supply OK” or “power supply NG” depending on whether or not the power supply voltage value in a state where a pseudo load corresponding to the normal operation after power ON is applied to the battery power supply 22 is equal to or higher than the necessary minimum voltage data V1. Here, when the output voltage value of the battery power source 22 falls below the necessary minimum voltage data V1 and is determined as “power source NG”, the remaining amount of the battery power source 22 stored in the ROM 13 in advance is determined. Power supply abnormality message data for prompting the user to run out is read and displayed on the liquid crystal display unit 21 (steps S2 → S3).
[0031]
On the other hand, the output voltage value of the battery power supply 22 in a state in which a pseudo load corresponding to the normal operation after the power supply is turned on is applied to the battery power supply 22 is not less than the necessary minimum voltage data V1 and judged as “power supply OK”. When the CPU 11 is set to the IR communication mode by operating the “IR” key 12a of the key input unit 12 in order to perform infrared data communication with an external device, for example, the pseudo load level setting ROM 20 stores the information in advance. The 8-bit pseudo load data “00101011” corresponding to the communication operation in the IR communication mode is read, and the 8-bit latch circuit 24 of the power supply monitoring unit 19 (see FIG. 2) is synchronized with the latch clock b from the CPU 11. The latch is set (steps S2 → S4 → S5).
[0032]
Then, the switches A3, A5, A7, A8 in the pseudo load circuit RA are turned on according to the load control signals C1 to C8 corresponding to the pseudo load data "00101011" latched in the 8-bit latch circuit, and the switches A1,. Since A2, A4, and A6 are turned off, the resistors R1, R2, and R4 of the pseudo load circuit RA are connected in parallel to the battery power source 22, and the IR in which R6 is connected in series. A pseudo load state corresponding to the communication operation in the communication mode is set.
[0033]
Thus, the output voltage of the battery power source 22 measured by the A / D converter 23 in a state where the pseudo load circuit RA sets a pseudo load corresponding to the communication operation in the IR communication mode. Is taken into the CPU 11 as battery voltage measurement data by the measurement control signal a from the CPU 11 and compared with the necessary minimum voltage data V2 corresponding to the communication operation in the IR communication mode stored in the pseudo load level setting ROM 20 in advance. (Step S6).
[0034]
That is, “power supply OK” or “power supply NG” depends on whether or not the power supply voltage value in a state where a pseudo load corresponding to the communication operation in the IR communication mode is applied to the battery power supply 22 is equal to or higher than the necessary minimum voltage data V2. Here, if the output voltage value of the battery power source 22 is equal to or higher than the necessary minimum voltage data V2 and it is determined that the power source is OK, then data communication according to the IR communication mode is performed. Processing is executed (steps S6 → S7).
[0035]
On the other hand, the output voltage value of the battery power supply 22 in a state in which a pseudo load corresponding to the communication operation in the IR communication mode is applied to the battery power supply 22 falls below the necessary minimum voltage data V2, and is determined as “power supply NG”. Then, the power failure message data for prompting the user to run out of the remaining battery power 22 stored in the ROM 13 in advance is read and displayed on the liquid crystal display unit 21 (steps S6 → S8).
[0036]
For example, when the CPU 232 is set to the 232C communication mode by operating the “232C” key 12b of the key input unit 12 in order to perform data communication with an external device in accordance with the RS-232C standard, it is stored in the pseudo load level setting ROM 20 in advance. The 8-bit pseudo load data “01000111” corresponding to the communication operation in the 232C communication mode is read out, and is synchronized with the latch clock b from the CPU 11 in the 8-bit latch circuit 24 of the power supply monitoring unit 19 (see FIG. 2). The latch is set (step S4 → S5).
[0037]
Then, the switches A2, A6, A7, A8 in the pseudo load circuit RA are turned on in accordance with the load control signals C1-C8 corresponding to the pseudo load data "01000111" latched in the 8-bit latch circuit, and the switches A1,. Since A3, A4, and A5 are OFF, the battery power supply 22 is connected to the resistors R1, R3, and R4 of the pseudo load circuit RA in parallel and 232C in which R5 is connected in series. A pseudo load state corresponding to the communication operation in the communication mode is set.
[0038]
Thus, the output voltage of the battery power supply 22 measured by the A / D converter 23 in a state where the pseudo load circuit RA sets a pseudo load corresponding to the communication operation in the 232C communication mode. Is taken into the CPU 11 as battery voltage measurement data by the measurement control signal a from the CPU 11 and is compared with the necessary minimum voltage data V3 corresponding to the communication operation in the 232C communication mode stored in the pseudo load level setting ROM 20 in advance. (Step S6).
[0039]
That is, “power supply OK” or “power supply NG” depends on whether or not the power supply voltage value in a state where a pseudo load corresponding to the communication operation in the 232C communication mode is applied to the battery power supply 22 is equal to or higher than the necessary minimum voltage data V3. Here, if the output voltage value of the battery power source 22 is equal to or higher than the necessary minimum voltage data V3 and it is determined that the power source is OK, then data communication corresponding to the 232C communication mode is performed. Processing is executed (steps S6 → S7).
[0040]
On the other hand, the output voltage value of the battery power supply 22 in a state where a pseudo load corresponding to the communication operation in the 232C communication mode is applied to the battery power supply 22 falls below the necessary minimum voltage data V3 and is determined as “power supply NG”. Then, the power failure message data for prompting the user to run out of the remaining battery power 22 stored in the ROM 13 in advance is read and displayed on the liquid crystal display unit 21 (steps S6 → S8).
[0041]
Further, for example, when the CPU 11 is set to the card access mode by operating the “card” key 12c of the key input unit 12 in order to perform data access with the PCMCIA card, the card access mode stored in the pseudo load level setting ROM 20 in advance. 8-bit pseudo-load data “01011001” corresponding to the access operation in FIG. 8 is read out and latched and set in the 8-bit latch circuit 24 of the power supply monitoring unit 19 (see FIG. 2) in synchronization with the latch clock b from the CPU 11. (Step S4 → S5).
[0042]
Then, the switches A2, A4, A5, A8 in the pseudo load circuit RA are turned on in accordance with the load control signals C1 to C8 corresponding to the pseudo load data "01010001" latched in the 8-bit latch circuit, and the switches A1,. A3, A6, and A7 are turned off. With this, the battery power source 22 is connected to the resistors R1 and R3 of the pseudo load circuit RA in parallel, and the card in which R6 and R7 are connected in series. A pseudo load state corresponding to the access operation in the access mode is set.
[0043]
Thus, the output voltage of the battery power supply 22 measured by the A / D converter 23 in a state where the pseudo load circuit RA sets a pseudo load corresponding to the access operation in the card access mode. Is taken into the CPU 11 as battery voltage measurement data by the measurement control signal a from the CPU 11 and compared with the necessary minimum voltage data V4 corresponding to the access operation in the card access mode stored in the pseudo load level setting ROM 20 in advance. (Step S6).
[0044]
That is, “power supply OK” or “power supply NG” depends on whether or not the power supply voltage value in a state where a pseudo load corresponding to the communication operation in the card access mode is applied to the battery power supply 22 is equal to or higher than the necessary minimum voltage data V4. Here, if the output voltage value of the battery power source 22 is equal to or higher than the necessary minimum voltage data V4 and “power source OK” is determined, then data communication corresponding to the card access mode is performed. Processing is executed (steps S6 → S7).
[0045]
On the other hand, the output voltage value of the battery power supply 22 in a state where a pseudo load corresponding to the communication operation in the card access mode is applied to the battery power supply 22 is lower than the necessary minimum voltage data V4, and is determined as “power supply NG”. Then, the power failure message data for prompting the user to run out of the remaining battery power 22 stored in the ROM 13 in advance is read and displayed on the liquid crystal display unit 21 (steps S6 → S8).
[0046]
Except for the monitoring process of the battery power source 22 when the power source is turned on, the switch A8 of the pseudo load circuit RA is turned off and disconnected, so that the battery power source 22 does not consume unnecessary current.
[0047]
Therefore, according to the PDA device equipped with the power supply monitoring device having the above-described configuration, the IR communication mode or the 232C communication mode is operated by operating the “IR” key 12a, “232C” key 12b, and “card” key 12c of the key input unit 12. When the card access mode is set, 8-bit pseudo load data corresponding to the operation in each mode is read from the pseudo load level setting ROM 20 and latched in the 8-bit latch circuit 24 of the power supply monitoring unit 19. The switches A1 to A8 of the pseudo load circuit RA are selectively turned on / off according to the above, and the resistors R1 to R8 are combined to give a pseudo load corresponding to the operation mode to the battery power source 22, and in the pseudo load state. Of the pseudo load level setting ROM 2 corresponding to each operation mode. The power supply OK message or the power supply NG is determined based on whether or not the necessary minimum voltage data V1 to V4 stored in the memory is greater than or equal to, and a power failure message or the like is displayed on the liquid crystal display unit 21. Whether the voltage level can withstand the load associated with subsequent processing operations can be monitored in advance, so that processing interruptions and operation errors due to voltage drop after operation can be prevented in advance. Become.
[0048]
In the embodiment, the pseudo load data for setting the pseudo load state corresponding to each operation mode in the pseudo load circuit RA of the power supply monitoring unit 19 is stored in the pseudo load level setting ROM 20 in advance. For example, in the card access mode, the pseudo load data may be set based on the operating current value written in advance as attribute information in the PCMCIA and JEIDA cards.
[0049]
【The invention's effect】
As described above, according to the power supply monitoring device of the present invention , when one of a plurality of types of communication functions of an electronic device is executed, pseudo load data corresponding to the communication is read from the pseudo load data storage unit. Whether or not the battery voltage is latched by the latch circuit of the pseudo load circuit and the load corresponding to the communication operation is generated by the pseudo load circuit by an appropriate combination of resistance groups and given to the battery, and the battery voltage can withstand the actual communication operation. Be monitored.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of an electronic circuit of a PDA device equipped with a power supply monitoring device according to an embodiment of the present invention.
FIG. 2 is a circuit diagram showing an internal configuration of a power supply monitoring unit provided in the PDA device.
FIG. 3 is a flowchart showing power supply monitoring processing in the PDA device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 ... CPU, 12 ... Key input part, 12a ... "IR" key, 12b ... "232C" key, 12c ... "Card" key, 13 ... ROM, 14 ... RAM, 15 ... IR interface, 16 ... RS-232C interface 17 ... PCMCIA card interface, 18 ... transmission / reception circuit, 19 ... power supply monitoring unit, 20 ... pseudo load level setting ROM, 21 ... liquid crystal display unit, 22 ... battery power supply, 23 ... A / D conversion unit, 24 ... 8-bit latch Circuit, RA ... pseudo load circuit, A1-A8 ... switch, R1-R7 ... resistance.

Claims (1)

In a power supply monitoring device provided in an electronic device having a plurality of types of communication functions and driven by a battery,
A pseudo load circuit comprising a resistor group, a switch group for controlling a combination of the resistance group, and a latch circuit for latching pseudo load data for designating an open / close state of the switch group;
Pseudo load data storage means for storing pseudo load data for designating an open / close state of a switch group of the pseudo load circuit so as to set a load corresponding to each communication operation for each of the plurality of types of communication functions;
Before executing the communication function of the electronic device, the corresponding pseudo load data is read from the pseudo load data storage means and latched in the latch circuit of the pseudo load circuit, and the load corresponding to the communication operation to be executed is set in the pseudo load data. A pseudo load setting means generated by a load circuit and applied to the battery;
Voltage measuring means for measuring the output voltage of the battery in a state where the load set by the pseudo load setting means is applied to the battery;
An abnormality notifying means for notifying the abnormality of the battery based on the measurement result by the voltage measuring means;
A power supply monitoring apparatus comprising:

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