JP5381182B2 - Electronic device life detection method and electronic device with life detection function - Google Patents

Description

  The present invention relates to a method for detecting the life of an electronic device having a capacitor for charging a power supply voltage inside the electronic device, and an electronic device with a life detection function.

  In a temperature controller, which is an example of various electronic devices, a program memory in which an application program (temperature control program) for temperature control is stored inside, and various temperature control is performed according to the temperature control program stored in the program memory. A CPU for executing processing, other various circuits, and the like are incorporated.

  This temperature controller has a built-in power supply for supplying an operating voltage to the internal circuit.

  In such a temperature controller, when power interruption occurs and the temperature control program operating on the CPU is suddenly terminated, the setting data may be destroyed. In such a case, the temperature control program does not operate normally when restarted. At that time, since such setting data is stored in, for example, the main memory, when the power is cut off, the stored contents are erased from the main memory. Therefore, in order to protect such data, it is necessary to perform processing for saving the data in the main memory to the nonvolatile memory at the end of the program.

  In this case, the charging voltage of the electrolytic capacitor in the power supply unit is used so that the operating voltage does not drop below the lower limit voltage required for operation immediately after the power is cut off before the data is saved in the nonvolatile memory. . Since the charging voltage of the electrolytic capacitor gradually decreases after power interruption, the power supply supplies the operating voltage to the internal circuit of the electronic device until the charging voltage of the electrolytic capacitor decreases to the reset voltage after power interruption. To be able to.

  And, after the power supply section is cut off, the data in the main memory is saved to the nonvolatile memory until the operating voltage can be supplied to the internal circuit of the electronic device, thereby protecting the data. To be able to.

  Therefore, when the life of the electrolytic capacitor comes to an end, for example, the conventional technology has already been proposed in which the life of the electrolytic capacitor is displayed as the life of the electronic device.

  In many of such prior arts, for example, in Patent Document 1, the electrolytic capacitor voltage decreases due to discharge after power interruption, but the time until the electrolytic capacitor voltage decreases to the reference voltage after power interruption (life measurement determination time) is long. This is a technique for determining the life of an electrolytic capacitor or the life of an electronic device depending on whether it is within a certain time.

  However, in the case of such a conventional technique, performance variations of peripheral electronic components other than the electrolytic capacitor are not taken into consideration. In other words, even if the time required for the electrolytic capacitor voltage to drop to the reference voltage after power interruption is within a certain time, it is saved due to variations in the performance of electronic components for saving the data in the main memory to the nonvolatile memory. Processing may not be possible. In this case, since the evacuation process cannot be performed, the life of the electronic device is inevitably determined, but the electrolytic capacitor has not reached the end of its life, so it is erroneously determined that the life is normal.

  In addition, the patent document in which the technique similar to patent document 1 is disclosed except patent document 1 is also mentioned below.

JP 2002-281735 A JP 7-163045 A JP-A-6-206262

  In the present invention, the lifetime of an electronic device can be reliably determined without depending on performance variations of peripheral electronic components including an electrolytic capacitor.

  The electronic device life detection method according to the first aspect of the present invention includes a data writing process for writing predetermined data in a nonvolatile memory within a time until the charging voltage of the capacitor decreases by a predetermined voltage at the time of power interruption, A life determination process for determining a life state of the electronic device from a data writing state to the memory at the time of the power interruption is performed.

  The power interruption and power on may be AC or DC.

  In the first aspect of the present invention, since the capacitor is discharged due to power interruption in the data writing process, the predetermined data is written in the nonvolatile memory within the time until the charging voltage is reduced by the predetermined voltage, so that the capacitor has the performance. When it is deteriorated or the performance of the peripheral electronic components is deteriorated, it is not possible to secure time for writing predetermined data to the memory, and data cannot be written. In the life determination process, the life state of the electronic device is determined from the data write state to the memory. For example, when all the predetermined data is written to the memory, it can be determined that the remaining life of the electronic device is sufficient. When only a part of the predetermined data is written, it can be determined that the remaining life of the electronic device is not sufficient, and when no predetermined data is written, it can be determined that there is no remaining life of the electronic device. become.

  In the present invention, the life of the electronic device is determined based on the state of data written to the memory. Therefore, it is possible to determine the life of the electronic device regardless of the performance variation of the capacitor and the surrounding electronic components. Thus, it is possible to eliminate the erroneous determination of the lifetime of the electronic device due to the variation in the performance of the conventional capacitor, and to accurately determine the lifetime of the electronic device.

  In the first aspect of the present invention, a preferable aspect is that the life determination process includes a step of reading data from the memory when power is turned on, a step of determining presence / absence of write data in the memory based on the read data, and the determination is a memory. And when there is no write data, a step of displaying the end of life of the electronic device is included. In this aspect, it is preferable that the user can easily recognize this by displaying the arrival of the electronic device life.

  In the first aspect of the present invention, another preferable aspect is that the life determination process reads data from the memory when power is supplied, and detects a data writing state in the memory based on the read data. Displaying the remaining life of the electronic device according to the amount of data written. This aspect is preferable because the user can easily recognize the remaining life of the electronic device from the display state of the electronic device life.

  In the first aspect of the present invention, in another preferred embodiment, the data writing process is performed in the nonvolatile memory within a time until the charging voltage of the capacitor decreases by a predetermined voltage when the power supply is stopped. It includes a step of writing data to each address by changing the address for writing data every certain period of time, and the above-mentioned life determination processing determines the remaining life of the electronic device depending on to which address in the memory the data has been written Including steps. In this aspect, it is preferable that the user can display the remaining life of the electronic device in a more specific stepwise manner as the display of the life of the electronic device, and can easily recognize the remaining life.

  In the first aspect of the present invention, in another preferred aspect, the data writing process includes a memory state determination process for clearing data stored in the memory after the lifetime determination process and determining a memory state from the cleared state. That is. In this aspect, it is preferable that the reason why data cannot be written to the memory is caused by the abnormality of the memory itself in addition to the life of the electronic device.

  An electronic device according to a second aspect of the present invention includes a voltage detection unit that detects a charging voltage of a capacitor, a CPU that executes a life detection process of the electronic device based on an output of the voltage detection unit, and a program for the life detection process And a non-volatile data write memory in which data used for life detection is written by the CPU. The CPU determines whether the power is turned off or turned on from the detection output of the voltage detection unit. When the power is cut off, a data writing process for writing predetermined data into the data writing memory is performed until the charging voltage of the capacitor decreases by a predetermined voltage. Life determination processing for determining the life state of the electronic device from the data writing state of And it is characterized in that is.

  In the second aspect of the present invention, a preferable aspect is that the CPU clears the data stored in the memory after the life determination process, and can execute the memory state determination process for determining the memory state from the cleared state. It is like that.

  According to the present invention, it is possible to reliably determine the lifetime of an electronic device without depending on performance variations of peripheral electronic components including a capacitor.

FIG. 1 is a diagram showing a schematic configuration of an electronic apparatus according to an embodiment of the present invention. FIG. 2 is a diagram showing a change characteristic of the charging voltage according to the deterioration state of the smoothing capacitor provided in the electronic apparatus of FIG. FIG. 3 is a flowchart for explaining the operation based on the detection of power interruption. FIG. 4 is a flowchart for explaining the operation when the power is turned on. FIG. 5 is a diagram showing an address of a memory to which data is written after power interruption and data to be written thereto. FIG. 6 is a diagram showing addresses of the memory from the data writing to the end of writing to the memory and data to be written to the memory.

  Hereinafter, a life detection method for an electronic device according to an embodiment of the present invention and an electronic device with a life detection function for implementing the same will be described in detail with reference to the accompanying drawings. The electronic apparatus of the embodiment is not particularly limited, and can include, for example, a temperature controller and other control devices. In the embodiment, for convenience of explanation, a switching power supply is used as a power supply. However, the present invention is not limited to this, and a DC power supply may be used.

  Referring to FIG. 1, an electronic apparatus according to an embodiment includes a power supply unit 1, a voltage detection unit 3, a CPU 5, a nonvolatile data write memory 7, a program memory 9, a work memory 11, and a display unit. 13. The power supply unit 1 is configured by a switching power supply, for example, and generates a DC voltage supplied from the commercial AC power supply 15 to each part in the electronic device. The switching power supply includes a primary side rectifier circuit 1a, a primary side smoothing circuit 1b, a switching circuit 1c, a transformer 1d, a secondary side rectifier circuit 1e, a secondary side smoothing circuit 1f, and a control circuit 1g. . The switching circuit 1c is switching-controlled by a control signal from the control circuit 1g that detects the secondary side voltage of the transformer 1d. The above switching power supply has a well-known configuration, and details thereof are omitted.

  In such a power supply unit 1, the secondary side smoothing circuit 1 f includes a large-capacity electrolytic capacitor (hereinafter simply referred to as a capacitor) 17. The capacitor 17 in the smoothing circuit 1f can supply an operating voltage to circuit means such as the CPU 5 until the charging voltage is gradually lowered to the reset voltage at the time of power interruption. .

  The voltage detector 3 detects the charging voltage of the capacitor 17. The charging voltage of the capacitor 17 will be described with reference to FIG. In FIG. 2, the horizontal axis represents time, the vertical axis represents the internal voltage of the electronic device, and the decrease of the internal voltage due to the discharge of the capacitor 17 after power interruption is caused by the capacitor 17 after performance degradation and the capacitor 17 before performance degradation This is a comparison. In the case of the capacitor 17 after the performance deterioration, the change in the internal voltage is indicated by a solid line, and the change in the internal voltage in the case of the capacitor 17 before the performance deterioration is indicated by a broken line. The internal voltage in this case corresponds to the charging voltage of the capacitor 17 of the power supply unit 1.

  In the power supply unit 1, the internal voltage after power interruption is generated by the charging voltage of the capacitor 17, but the internal voltage gradually decreases due to the discharging of the capacitor 17. The voltage detection unit 3 detects such a change in the charging voltage of the capacitor 17 in the power supply unit 1 and inputs the detection output to the CPU 5.

  The program memory 9 is a memory in which an electronic device life detection processing program is stored in addition to the electronic device system program. If the electronic device is a temperature controller, for example, the program memory 9 stores a temperature control program as an application program in addition to the system program, and also stores the electronic device life detection processing program in the present embodiment. In the case where the electronic device is a temperature controller, description of this temperature control program is omitted. The work memory 11 is a memory used by the CPU 5 for executing various operations. Then, the CPU 5 detects the lifetime of the electronic device as described with reference to FIGS. 3 to 6 in accordance with the electronic device lifetime detection processing program stored in the program memory 9.

  The CPU 5 determines from the detection output of the voltage detection unit 3 that the charging voltage of the capacitor 17 has dropped to the power interruption detection voltage, and determines that it is a power interruption, and when the charging voltage of the capacitor 17 further decreases to the reset voltage. The internal voltage of the capacitor 17 is reset, assuming that the operating voltage cannot be supplied to the internal circuit of the electronic device.

  The CPU 5 performs control to write predetermined data into the data write memory 7 within a time until the charging voltage of the capacitor 17 is lowered from the interruption detection voltage to the reset voltage due to interruption. The above time is the time for writing data to the data write memory 7. In this case, for the purpose of detecting the life of the electronic device, the data written in the data write memory 7 may be any data. Further, the data write memory 7 can be a data saving memory for writing and saving program data from the program memory 9 and various work data required from the work memory 11.

  As shown in FIG. 2, the data write time until the charging voltage of the capacitor 17 drops from the interruption detection voltage to the reset voltage due to the interruption of power is t0 for the capacitor before the performance deterioration, and t1 for the capacitor after the performance deterioration. (<T0).

  As apparent from FIG. 2, when the performance of the capacitor 17 deteriorates, the data write time becomes shorter and the data write time cannot be secured. In the present embodiment, the data written in the data write memory 7 is read, and the life of the electronic device can be detected from this written state.

  With reference to the flowchart of FIG. 3, the data write processing operation by the CPU 5 at the time of power interruption will be described. In this process, when power interruption is detected in step n31, data is written in the data write memory 7 in step n32. In step n33, it is determined whether data writing has been completed. If data writing has not been completed, the process returns to step n32 to continue data writing. If it is determined in step n33 that data writing has been completed, the flag is turned on in step n34.

  With reference to the flowchart of FIG. 4, the electronic device life determination processing operation by the CPU 5 when the power is turned on will be described. This process is a process of determining the life state of the electronic device from the data write state to the data write memory 7 at the time of power interruption. In step n41, when the CPU 5 detects that the power is turned on by the detection output of the voltage detector 3, the CPU 5 reads the write data from the data write memory 7 in step n42. In step n43, the CPU 5 determines the presence or absence of predetermined write data in the data write memory 7 as a result of reading data from the data write memory 7. If the CPU 5 determines in step n43 that all the predetermined write data has not been written and the flag is not ON, in step n44, the display unit 13 displays the lifetime of the electronic device, and the user has reached the lifetime of the electronic device. Control to let you know. When the CPU 5 determines in step n43 that the predetermined write data exists and the flag is ON, the display unit 13 performs control to notify the user that the electronic device life has not come by not performing display processing related to the electronic device life.

  The electronic device life determination process is completed by the above steps.

  On the other hand, in the embodiment, the reason why data cannot be written to the data write memory 7 is that the data write memory 7 itself is abnormal in addition to the above-mentioned electronic device life. In such a case, the life of the electronic device cannot be detected unless it is possible to identify the cause of the inability to write data to the data write memory 7.

  Therefore, in the embodiment, whether the reason why the data cannot be written to the data write memory 7 by performing the processing after step n45 is due to the above-mentioned electronic device life or that the data write memory 7 itself is abnormal. It is possible to distinguish whether or not. That is, if the CPU 5 determines in step n44 that the flag is ON, the process proceeds to step n45. In this step n45, the data written in the data write memory 7 is cleared and the flag is turned OFF.

  In step n46, the CPU 5 performs data read processing from the data write memory 7. Even if the CPU 5 clears the data in step n47 and step n45 and turns the flag OFF, if the data is read in step n46, the CPU 5 assumes that the data is not cleared and the flag is not turned OFF. Thus, it is determined that there is an abnormality in the data writing memory 7 itself. On the other hand, if there is no data read in step n46, it is assumed that the flag has been turned off by clear processing, and in step n49, normal operation is controlled assuming that there is no abnormality in the data write memory 7 itself.

  With reference to FIG. 5, predetermined data writing to the data writing memory 7 after power interruption will be described. FIG. 5 shows write data to each address of the data write memory 7. Write data A is written at address 0000, write data B is written at address 0001, and write data Z is written at address XXX. In the embodiment, the address XXXX is a predetermined data write address at the time of power interruption, and the data Z is written as the predetermined write data. In the flowchart of FIG. 3, the CPU 5 writes the data Z to the address XXXX of the data write memory 7 as the predetermined data write at step n33. When all the data Z has been written, the flag is turned ON. On the other hand, in the flowchart of FIG. 4, data is written to the address XXXX of the data write memory 7 in the data read process in step n42, the determination process that there is predetermined write data in step n43, and the processes in steps n45 to n47. Data Z is used for the processing.

  The above-mentioned predetermined data writing to the data writing memory 7 is based on the condition that all of the data has been written, but it is also possible to detect the life of the electronic device from the data writing state to the data writing memory 7. it can. FIG. 6 shows a state of writing to the data write memory 7 in that case.

  With reference to FIG. 6, a predetermined data write to the data write memory 7 after power interruption will be described. FIG. 6 shows write data to each address of the data write memory 7. Based on the detection output of the voltage detection unit 3, the CPU 5 stores the address for writing data in the data write memory 7 within a certain period of time after the charging voltage of the capacitor 17 is reduced to the reset voltage after the interruption of power. And write data to each address.

  In FIG. 6A, the address 0000 is the data write start address, and the address XXXX is the data write end address. As described above, when data is written from the address 0000 to the address XXXX of the data write memory 7, all of the predetermined data has been written, and the CPU 5 has a sufficient electronic device life on the display unit 13, for example. And In this case, it is also possible to cause the CPU 5 to perform a lifetime calculation and display a specific lifetime on the display unit 13 from the calculation result.

  In FIG. 6B, the address 0000 is the data write start address, and the address 00XX is the data write end address. Data is not written from address 00YY to address XXXX. In such a case, all the writing of the predetermined data is not completed, and the data writing is completed at the address 00XX in the middle. Therefore, the CPU 5 calculates the number of write addresses and displays it in comparison with FIG. For example, the remaining life of the electronic device is specifically displayed on the unit 13. In other words, the display of the remaining lifetime is a prediction of the lifetime of the electronic device.

  As described above, in the present embodiment, the data write processing for writing predetermined data in the data write memory 7 within the time until the charging voltage of the capacitor 17 is reduced by a predetermined voltage at the time of power interruption, and the above-mentioned when the power is turned on. Since the life determination process for determining the life state of the electronic device from the data write state to the data write memory 7 at the time of power interruption is performed, the data write process to the data write memory 7 at the time of power interruption If the capacitor 17 is not deteriorated in performing the above, it is possible to secure time for writing predetermined data to the data write memory 7 and write data. On the other hand, when the capacitor 17 is deteriorated or the peripheral electronic components are deteriorated, it is not possible to secure time for writing the predetermined data in the data write memory 7, and data cannot be written.

  In this embodiment, since the life state of the electronic device is determined from the data writing state to the data write memory 7, the life of the electronic device can be detected regardless of the performance variation of the capacitor 17 and the surrounding electronic components. This makes it possible to accurately determine the lifetime of the electronic device without the erroneous determination of the lifetime of the electronic device due to variations in the performance of the conventional capacitor.

DESCRIPTION OF SYMBOLS 1 Power supply part 1a Rectifier circuit 1b Smoothing circuit 17 Capacitor 3 Voltage detection part 5 CPU
7 Data writing memory

Claims (7)

A method of detecting the lifetime of an electronic device with respect to an electronic device provided with a capacitor that supplies the charging voltage as an operating voltage to an internal circuit of the electronic device when power is interrupted,
A data writing process for writing predetermined data in a nonvolatile memory within a time until the charging voltage of the capacitor decreases by a predetermined voltage at the time of power interruption;
Life determination processing for determining the life state of the electronic device from the data writing state to the memory at the time of power interruption when power is turned on
An electronic device lifetime detection method characterized by comprising: The above life judgment process
Reading data from the memory when the power is turned on;
Determining the presence or absence of write data in the memory based on the read data;
A step of displaying the end of life of the electronic device when the determination is no data written in the memory;
The electronic device life detection method according to claim 1, wherein The above life judgment process
Reading data from the memory when power is supplied;
Detecting a state of writing data to the memory based on the read data;
Displaying the remaining life of the electronic device according to the amount of data written;
The electronic device life detection method according to claim 1, wherein The above data writing process
In the time until the charging voltage of the capacitor decreases by a predetermined voltage at the time of power failure, the nonvolatile memory includes a step of changing the address for writing data every predetermined time and writing data to each address,
The above life judgment process
The step of determining the remaining life of the electronic device according to which address in the memory has been written,
The electronic device life detection method according to claim 1, further comprising:   5. The electronic device life detection method according to claim 1, further comprising a memory state determination process for clearing data stored in the memory after the life determination process and determining the state of the memory from the cleared state. 6. In electronic equipment with a capacitor that supplies the charging voltage as an operating voltage to the internal circuit of the electronic equipment when power is interrupted,
A voltage detection unit that detects a charging voltage of the capacitor; a CPU that executes a life detection process of the electronic device based on an output of the voltage detection unit; a program memory that stores a program for the life detection process; A nonvolatile data writing memory in which data used for life detection is written by the CPU;
The CPU determines from the detection output of the voltage detection unit whether the power is cut off or the power is turned on, and data for writing predetermined data in the data writing memory until the charging voltage of the capacitor is reduced by a predetermined voltage at the time of power interruption When the power is turned on and the power is turned on, the life determination process for determining the life state of the electronic device from the data write state to the data write memory at the time of power interruption can be performed. An electronic device characterized by that.   7. The CPU according to claim 6, wherein the CPU clears the data stored in the memory after the life determination processing and can execute the memory state determination processing for determining the state of the memory from the cleared state. Electronic equipment.

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