JPH11249767A - Power source controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smoothly return a microcomputer to its ordinary operation mode at the time of power recovery. SOLUTION: A power source controller incorporating a microcomputer 1 and having an ordinary mode and a low power consumption mode is provided with a power supply state detecting function 3 for detecting the output state of a power source 2, a power failure discriminating function 5 for discriminating whether it is a power failure or not based on a signal of the power supply state detecting function 3, and a power failure recovery processing function 6 for performing a prescribed processing based on the discrimination result of the power failure discriminating function 5. When a power failure is discriminated by the power failure discriminating function 5 during a prescribed power failure recovery standby time, the mode is switched to the lower power consumption mode by the power failure recovery processing function 6, and after the lapse of the power failure recovery standby time, the mode is switched to the ordinary mode, or only when the power failure recovery is discriminated by discriminating the power failure again after the lapse of the power failure recovery standby time, the mode is switched to the ordinary mode so that the change to the ordinary mode at the time of power failure recovery can be smoothly performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply control device for controlling a power supply state.

[0002]

2. Description of the Related Art A drive mechanism in a microcomputer (hereinafter, referred to as "microcomputer" in this specification) is usually driven by a stable power supply such as a commercial power supply, and is switched to a standby power supply such as a battery in the event of a power failure. Then, the mode is switched to a low frequency mode (for example, a mode of 32.76 kHz, a low power consumption mode) for a predetermined time, and the minimum processing by the microcomputer is performed to prepare for the recovery from power failure. ) To perform normal processing by the microcomputer.

[0003]

By the way, the microcomputer processing control method from the power failure to the recovery from the power failure does not pose a special problem in the case of a microcomputer built-in device having a stable power supply such as a commercial power supply. In the case of a device with a built-in microcomputer that is driven by a power supply that does not have a sufficient margin, such as a solar cell-driven solar lighting device, the following problem occurs.

[0004] For example, as shown in FIGS. 6 (A) and 6 (B), a solar cell driving type solar lighting device 10 has a lighting prism (not shown) in a dome-shaped cover 11 which is convex upward. A solar driving device (not shown) that controls the light-receiving prism by receiving a command from a control device 12 having a microcomputer 12M so that the light-receiving prism has an appropriate rotation angle in accordance with the position of the sun. 13 to be driven using electric power. 14 is a solar cell 13
Is a power supply line.

In this case, since the drive power supply of the microcomputer built-in device is a solar cell, it is normally used in the daytime. However, the power depends on, for example, unstable factors such as the weather, and the squall and Due to sudden changes in weather conditions such as showers, snow and clouds (including the case where fallen leaves etc. are on the solar cell), the supply voltage suddenly drops below a predetermined voltage level. However, if the control process from the power failure state to the recovery from the power failure is the control method of immediately switching to the normal mode as described above, the following problem occurs.

That is, during the power failure period, the processing of the microcomputer 12M is switched to the standby power supply, and the processing of the low power consumption mode (sub clock mode) in which only the basic processing such as the storage of the data and the like built in the microcomputer 12M is performed. To prepare for power recovery, if the power of the solar cell recovers due to the recovery of the weather, etc., and the processing of the microcomputer 12M is switched to the normal mode (main clock mode) immediately after the power recovery, the power is still restored immediately after recovery. Since it is necessary to supply power to all loads from a solar cell with no margin, it is easy to return to a power outage state again. If such an unstable power supply state is repeated, this may cause a decrease in the performance of the IC elements constituting the microcomputer 12M, and may cause a state in which the processing of the microcomputer 12M cannot keep up with the command, that is, a runaway state of the microcomputer. there were. In such a situation, in a commercial power supply-driven solar lighting device, when the device is initially installed in a building and the power is directly supplied from a commercial power supply using a temporary bare wire terminal, the power is supplied due to poor contact or the like. Stops, and the microcomputer of the same device goes into a power outage or power outage recovery state.In such a case, if there is no protection for the microcomputer processing, the microcomputer may run out of control as described above. there were.

An object of the present invention is to provide a power supply control device applied to such a microcomputer built-in device driven by a power supply having a sufficient margin.

[0008]

In order to solve the above-mentioned problems, a power supply control device according to the present invention has a built-in microcomputer and includes a normal mode and a low power consumption mode that operates with less power than the normal mode. A power supply control device provided with a power supply state detection function for detecting an output state of a power supply in the form of an electric signal; a power failure determination function for determining whether or not a power failure has occurred based on the electric signal of the power supply state detection function; and a power failure determination function. Power failure recovery processing function to perform predetermined processing based on the determination result of, based on the electric signal of the power state detection function,
When the power failure is determined by the power failure determination function, the microcomputer is switched to the low power consumption mode during the predetermined power failure recovery standby time by the power failure recovery processing function, and when the power failure recovery standby time has elapsed, the power failure recovery is performed. The system was configured to switch to the normal mode in consideration of this.

Alternatively, when a primary power failure is determined by the power failure determination function based on the electric signal of the power supply state detection function, a predetermined power failure recovery standby is performed by the power failure recovery processing function. During the time period, the mode is switched to the low power consumption mode, and when the standby time for recovery from power failure has elapsed, the power state detection function and the power failure determination function are operated again,
When the next power failure is determined and the power failure is not determined based on the former electric signal, that is, when the power failure recovery is determined by the latter, the power failure recovery processing function may be used to switch to the normal mode.

In this case, the primary or secondary power failure determination or the power failure recovery determination by the power failure determination function is performed based on one or more detection signals from the power supply state detection function. do it. Further, based on a plurality of detection signals from the power supply state detection function, when the power outage determination function performs a primary or secondary power outage or power outage recovery determination, during a plurality of detection signals, The detection may be performed based on the presence of a large number of detection signals for determining that the power failure has been recovered, or alternatively, the detection signal for determining that the power failure or the recovery from the power failure has been continuously performed during the detection time during a plurality of detection signals. Alternatively, the determination may be made based on occurrence of a predetermined number of times (predetermined time). Further, when the power outage judging function judges a primary or secondary power outage or power outage recovery based on an electric signal from the power state detecting function, the detecting operation and the judging operation are continued for a predetermined time. Alternatively, the determination may be performed. In addition, each of these control methods is driven by various power supplies, various types of solar lighting devices using a reflecting mirror or the like in addition to a lighting lens in a lighting unit, or a solar cell driven solar device in which a lighting lens is disposed in a lighting unit. It is extremely effective to apply it to a light lighting device.

According to the control by the power supply control device, the microcomputer is forcibly switched to the low power consumption mode for a predetermined standby time after the power failure is determined. Even if the return is repeated, an undesired operation such as runaway of the microcomputer does not occur due to the standby time during that period, and the mode can smoothly shift to the normal mode after the recovery from the power failure. Further, if the recovery from the power failure is determined again after the elapse of the standby time, the transition to the normal mode after the recovery from the power failure can be performed more smoothly.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to one embodiment shown in FIGS. FIG. 1 is a block diagram illustrating an example of a power supply control device according to the present invention. A case where the device is applied to a solar lighting device will be described. In the figure, reference numeral 1 denotes a microcomputer (microcomputer) constituting, for example, a control device of a sunlight collecting device. Reference numeral 2 denotes a power supply device, which is composed of a solar cell. 3 is a power state detection function,
For example, it has an electric signal detection function such as a voltage detection circuit, detects an electric signal such as an output voltage of the power supply device 2, and transmits the detection signal E to the microcomputer 1. Reference numeral 4 denotes a load, for example, in the case of a sunlight lighting device, a rotary driving device including a motor and a gear mechanism for driving a lighting prism (not shown) constituting the device, and a power supply electric circuit. Reference numeral 5 denotes a power failure judging function, which comprises, for example, a comparison circuit with a reference electric signal, compares an electric signal E provided from the power supply state detecting function 3 with a predetermined reference electric signal to judge whether or not there is a power failure, and outputs a judgment signal F put out. Note that the electric signal E output from the power state detection function 3
It is preferable to use a voltage signal. For example, when a reference voltage of 5 V, which is a reference voltage of a motor operated by a microcomputer, is set as a reference voltage, the output voltage of the power supply device 2 becomes 5 V or less by the power supply state detection function 3. When a power failure is detected, the power failure determination function 5 may be set to determine a power failure. Note that, depending on the load on the microcomputer 1, the electric signal E
Can be used as the current. Also, in FIG. 1, for the sake of convenience, the power failure determination function 5 and the power failure recovery processing function 6 described below are described as being performed by hardware, but these functions are stored in the microcomputer 1 by a program that executes these functions. Of course, it is a function that can be processed by software by incorporating it. Reference numeral 6 denotes a power failure recovery processing function, which comprises, for example, a counter, a timer, and the like, which determines a predetermined processing procedure by the microcomputer after the recovery from the power failure, and issues a predetermined processing command G. Next, embodiments of the present invention will be described with reference to FIG. 1 in addition to the flowcharts of FIGS. 2 to 4 and the time charts shown in FIG.

First Embodiment: FIG. 2 shows a flow chart of this embodiment. As shown in FIG. 5 (A), the control of the present embodiment is based on the determination of the power failure at the time point t ₁ (based on the determination signal F of the power failure determination function 5 in FIG. (The same applies hereinafter) when (ST
1. After that, the microcomputer 1 is switched to the sub-clock mode (low power consumption mode) to wait in a state where normal processing is not performed until the predetermined power failure recovery standby time T _H elapses. in time t ₂ to time T _H has elapsed (YES in ST6) is regarded as a "power failure recovery" without performing the determination again power failure or power failure recovery (referred to as second-order determination), as shown by a broken line power failure recovery processing function at t ₂ 6 issues an switching instruction G to the normal mode, switches the microcomputer 1 to the main clock mode is a control method which is adapted to shift to the normal mode (ST7). The power recovery wait time T _H in this case, for example, 1 minute to 3 minutes of time is suitable. Step S
T2 of NO → each step of the step ST3 → Step ST4 is a step for performing pre-set of the power failure recovery wait time T _H which is performed before the power failure condition. In addition, every time the power failure is determined even after the transition to the normal mode, FIG.
The same control is performed based on the steps in the flowchart of FIG.

Second Embodiment: FIG. 3 shows a flowchart of this embodiment. Control of the present embodiment, after the determination of the primary power failure at time t ₁ as shown in the flow diagram and illustration of FIG. 3 5 (B), control up power recovery waiting time T _H has elapsed (ST11 → ST12 YES → ST16)
Is completely equivalent to the first embodiment. That control of this embodiment is different from the control of the first embodiment, at the time t ₂ when the power failure recovery time T _H has elapsed, not immediately switched to the main clock mode microcomputer, second-order determination In other words, in the second determination, the power failure determination function 5 determines that “no power failure”, that is, “power failure recovery” in the second determination, in that the determination is made again based on the output of the power supply state detection function 3 in FIG. only when the determination (YES in ST17), for example, at time t _3, the switching command G is issued from the power failure recovery processing function 6, switching the microcomputer 1 to the main clock mode shifts to the normal mode (ST1
8). If the power recovery is not determined (ST1)
7), control is performed to temporarily clear the operation during standby for recovery from power failure (ST19). Other operations are the same as in the first embodiment, and will not be described again.

Third Embodiment: FIG. 4 shows a flowchart of this embodiment. To summarize the characteristics of the control of the present embodiment, when determining the recovery from power failure, the counter and the timer in the power failure determination processing function shown in FIG. This is a method in which a sampling check is performed by using the method described above to determine the restoration from a power failure. To describe this procedure a little more specifically, the number of sampling checks is, for example, an odd number of 15 times. For example, when 15 times of sampling checks are performed, a large number (8 times) or more of them is used. If the result of the sampling check indicates that the power failure has been recovered, the determination based on the majority principle is performed, such as determining that the power failure has been recovered. As a sampling check speed, it is appropriate to perform, for example, one sampling check per second. The algorithm of this control will be described below with reference to FIG. 1 in addition to FIG. In the microcomputer 1, when an electric signal in a power failure state is detected by the power supply state detection function 3 and the power failure recovery determination processing starts (ST21), the power failure determination function 5 and the power failure recovery processing function 6 perform a power failure recovery determination. Is performed (ST
22), every time the power failure determination function 5 determines whether or not there is a power failure recovery, the number of times of the determination is reduced from the number of determinations (for example, 15) to 0 (ST2).
6) The determined number of times, which is determined as the power failure recovery during the number of times of determination, exceeds the reference number of times (eight times) (YES in ST27),
Further, when the number of times of power supply becomes equal to or more than the specified number (eight times) (YES in ST28), the clock mode of the microcomputer is switched to the main mode, and the mode is shifted to the normal mode (ST29). In ST27, if the number of times of restoration from power failure is less than the reference number (8) (ST27)
NO), when the presence of power is confirmed by the power failure determination function (YES in ST30), the number of times of presence of power is added (ST31). When the presence of power is not confirmed in ST30 (NO in ST30), It does not shift to the normal mode as it is. When the number of times of power supply is less than the specified number of times (eight times) in ST28 (NO in ST28), the power failure recovery determination is initialized (ST32). In addition, NO, ST23, and ST24 of step ST22 in FIG. 4 are steps for setting the number of times of determination of the number of samplings and the number of times of power supply before power failure recovery determination before the power failure. FIG. 5C shows a time chart when this control method is applied to the primary determination.

Fourth Embodiment: In the third embodiment, the judgment of the power failure or the recovery from the power failure is not made by one check as in the first and second embodiments, but is performed by a plurality of sampling checks. Was performed to make the determination. In the present embodiment, as shown in the time chart of FIG.
The control is such that, from the time point t ₁ when the power failure state is detected, the determination of the power failure recovery is continuously performed for a predetermined section (T _K ), and the determination of the power failure recovery is made. It should be noted that the algorithm of the present embodiment is similar to that of the third embodiment, so that the flow chart is omitted from the drawing.

Other Embodiments: The above-described first to fourth embodiments show basic embodiments of the present invention, and the present invention combines these embodiments with various modifications. Can be considered. For example, although in the second embodiment shows the case of performing the power failure detection performed at the time t ₁ by one sampling check, based on multiple sampling checks shown the determination in the third embodiment Do
Furthermore a method of performing, based on the sampling check of the power failure recovery determination even multiple of the waiting time T _H after the end time t ₄ of conceivable (Fig. 5 (E)). Alternatively, the power failure determination at time t ₁ is determined by one sampling check, and the recovery from power failure at time t ₂ is determined based on a plurality of sampling checks (FIG. 5).
(F)) Further, a method of judging a power failure performed at the time t ₁ by a plurality of sampling checks and determining recovery from the power failure at the time t ₂ by a single sampling check (FIG. 5 (G)) may be used. good. Further, the predetermined section T _K in which the check is performed in the fourth embodiment may be equal to or different from the standby period T _H in the first embodiment.

According to the power supply control device of the present invention, in each of the above-described embodiments, the microcomputer shifts to the normal processing mode after a predetermined standby time has elapsed after the detection of the power failure state. The probability of shifting to the processing state of the microcomputer in a stable power supply state is greatly reduced, and runaway of the microcomputer can be prevented. Furthermore, if the recovery from the power failure is determined again after the elapse of the standby time, the transition to the main clock mode after the recovery from the power failure can be performed more smoothly.

In the above embodiment, the normal mode has been described as the mode using the main clock, and the low power consumption mode has been described as the mode using the sub clock (lower frequency than the main clock). Alternatively, the present invention may be applied to a case where a plurality of clocks are not provided. For example, in the low power consumption mode, the present invention can be applied to a case where a plurality of modes having different power consumptions are provided by operating at low power by reducing the number of processes and the like as compared with the normal mode. It is possible. Further, as the solar lighting device of the above-described embodiment, a solar cell driven solar lighting device in which a lighting prism is disposed in a lighting unit as illustrated in FIG. 6 has been described, but the present invention is applied. The solar lighting device is not limited to the one having this structure. That is,
The power source is driven not only by the solar cell but also by a power source including a commercial power source (AC, DC), a lighting unit having a lighting lens or a reflecting mirror, a driving device for driving the lens or the mirror, and a physical position of an installation location. The present invention can be applied to various types of solar lighting devices including a control device that controls the driving device based on the orientation and date and time of the installation state. Again,
When the output of the power supply of the solar lighting device becomes insufficient power to drive a required mechanism of the solar lighting device, it is determined that this is a power outage, and is sufficient to drive the required mechanism. In such a case, the control may be performed so as to determine the recovery from the power failure.

[0020]

Since the power supply control device of the present invention performs control as described above, it has the following excellent effects. (1) As described in claim 1, after a power failure is determined, a predetermined power failure recovery standby time is temporarily switched to a low power consumption mode, which is a low frequency mode of the microcomputer, and after a lapse of the time, the microcomputer is switched to a high frequency mode. If the power supply is switched to the normal mode, the processing of the microcomputer during the time when the power supply is most likely to be unstable immediately after the power failure will be performed in the low power consumption mode with low power consumption. Also, the processing of the microcomputer from the power failure to the recovery from the power failure can be smoothly shifted to the normal mode without causing the microcomputer to run away. (2) As described in claim 2, after the primary power failure determination is performed and the power failure recovery standby time has elapsed, the secondary power failure determination is performed, and only when the recovery from the power failure is confirmed. If the microcomputer is switched to the high-frequency normal mode, the microcomputer is shifted to the normal mode after confirming that the output state of the power supply is stabilized. Can be done. (3) As described in claim 3, the first power outage determination is made by 1
In the case of performing a single or multiple sampling check signal, the determination can be performed quickly in the case of a single sampling check, while in the case of a multiple sampling check, the determination is performed with a single sampling check signal. Rather, the accuracy of the power outage determination can be improved. (4) As described in claim 4, the second power outage judgment is made by 1
In the case of performing a single or multiple sampling check signal, the determination can be made quickly in the case of a single sampling check, while in the case of a multiple sampling check, the determination is performed with a single sampling check signal. Rather, the accuracy of the power outage determination can be improved. (5) As described in claim 5, when the primary or secondary power outage or power outage recovery is determined by a plurality of sampling checks using the majority rule, simple arithmetic processing can be performed. The above determination can be made. (6) As described in claim 6, when the power failure or power failure recovery detection signal continuously reaches a predetermined number of times (predetermined time) during the predetermined check time, the power failure or power failure recovery is determined. A highly accurate determination can be made in a short time. (7) As described in claim 7, when the determination of the power failure or the recovery from the power failure is continuously performed, the claims 1 or 2 are provided.
The power failure recovery standby time is forcibly provided as described in, and the probability of quickly knowing the power failure recovery state of the power supply is increased as compared with the case where the determination operation is not performed, and the setting of the power failure recovery standby time is short. In the case of the power supply state where the recovery from the power failure cannot be confirmed even in the second power failure determination,
Since the determination operation of the power failure after the first power failure is continuously performed, the timing of recovery from the power failure can be detected with the best timing, and the microcomputer can be smoothly shifted to the normal mode. (8) As described in claim 8, when the power supply control device of the present invention is applied to processing of a microcomputer built in a control device of various types of sunlight collecting devices including those using a reflection mirror, a power supply control device is provided. When the output status becomes equivalent to a power failure,
The switching of the processing of the microcomputer from the state corresponding to the power failure to the recovery from the power failure can be performed quickly, accurately, and smoothly without causing the microcomputer to run away. (9) As described in claim 9, when the power supply control device of the present invention is applied to processing of a microcomputer built in a control device of a solar cell driving type solar lighting device, a solar cell serving as a power supply is provided. When the output state changes drastically due to weather conditions and becomes a state equivalent to a power failure, switching of the processing of the microcomputer from the state corresponding to the power failure to the recovery from the power failure can be performed quickly and accurately without causing the microcomputer to run away. And smoothly.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an example of a circuit configuration of a power supply control device according to the present invention.

FIG. 2 is a flowchart showing an operation of the first exemplary embodiment of the present invention.

FIG. 3 is a flowchart showing an operation of the second exemplary embodiment of the present invention.

FIG. 4 is a flowchart showing an operation of the third exemplary embodiment of the present invention.

FIG. 5 shows an example of power failure and power failure recovery timing in each embodiment of the present invention.
(B) shows the case of the second embodiment, FIG. (C) shows the case of the third embodiment, and FIG. (D) shows the case of the fourth embodiment. In the case of the form of FIG.
(G) shows the cases of the other embodiments.

FIGS. 6A and 6B show an example of the configuration of a solar cell-driven solar lighting device which is considered to be most suitable for applying the present invention. FIG. 6A is a front view, and FIG. 6B is a side view. .

[Explanation of symbols]

 1: microcomputer (microcomputer) 2: power supply device 3: power supply state detection function 4: load 5: power failure judgment function 6: power failure recovery processing function 10: sunlight lighting device 12: control device 12M: microcomputer (microcomputer) 13: Solar cell

Claims (9)

[Claims] 1. A power supply device incorporating a microcomputer and having a normal mode and a low power consumption mode operating with less power consumption than the normal mode, wherein a power supply for detecting an output state of the power supply in the form of an electric signal. A power failure determination function that determines whether or not a power failure has occurred based on an electric signal of the power supply state detection function; and a power failure recovery processing function that performs predetermined processing based on a determination result of the power failure determination function. When a power failure is determined by the power failure determination function based on the electric signal of the state detection function, the power failure recovery processing function switches to a low power consumption mode during a predetermined power failure recovery standby time, and the power failure recovery standby time elapses. The power control device is characterized in that when the power failure is restored, it is considered that the power failure has been restored, and the mode is switched to the normal mode. 2. A power supply device incorporating a microcomputer and having a normal mode and a low power consumption mode operating with less power consumption than the normal mode, wherein a power supply for detecting an output state of the power supply in the form of an electric signal. A state detection function, based on an electric signal of the power supply state detection function, a power failure determination function of determining whether or not a power failure, and a power failure recovery processing function of performing a predetermined process based on a determination result by the power failure determination function, When a primary power failure is determined by the power failure determination function based on the electric signal of the power supply state detection function, the power failure recovery processing function switches to a low power consumption mode during a predetermined power failure recovery standby time. When the standby time for recovery from power failure has elapsed, the power state detection function and the power failure determination function are activated again to determine a second power failure and to perform a power failure based on the former electric signal. Determining that there is no, namely power failure recovery and when the latter is determined, the power supply control device which is characterized in that the switched to the normal mode by power failure recovery processing function. 3. The power failure determination function according to claim 1, wherein the primary power failure determination is performed based on one or more detection signals from the power supply state detection function. 3. The power supply control device according to 2. 4. A secondary power outage or power outage recovery determination by the power outage determination function performed after the elapse of the power outage recovery standby time is performed based on one or more detection signals from the power state detection function. The power supply control device according to claim 2, wherein: 5. When the power failure determination function determines a primary or secondary power failure or recovery from a power failure based on a plurality of detection signals from the power supply state detection function, a plurality of detection signals are provided. 5. The power supply control device according to claim 3, wherein the determination is made based on the fact that there are a large number of detection signals for determining power failure or recovery from power failure. 6. 6. The method according to claim 6, wherein the power failure determination function determines a primary or secondary power failure or recovery from the power failure based on a plurality of detection signals from the power supply state detection function. 5. The method according to claim 3, wherein a detection signal for determining a power failure or recovery from the power failure occurs a predetermined number of times (a predetermined time) continuously during the detection time.
The power supply control device according to claim 1. 7. When the power outage determination function determines a primary or secondary power outage or power outage recovery based on an electric signal from the power supply state detection function, the detection operation and the determination operation are performed. The power supply control device according to any one of claims 1 to 5, wherein the determination is performed by continuously performing the determination for a predetermined time. 8. A lighting unit having a lighting lens or a reflection mirror, a driving device for driving the lens or the mirror, and a control for controlling the driving device based on the physical position of the installation location, the orientation of the installation state, and the date and time. In a solar lighting device equipped with a device, when the output of the power supply of the solar lighting device is insufficient power to drive the required mechanism of the solar lighting device, it is determined that this is a power outage The power supply control device according to any one of claims 1 to 7, wherein it is determined that a power failure has been restored when the power is sufficient to drive the required mechanism. 9. At least one daylighting prism disposed in a daylighting unit, a rotary driving device for driving the daylighting prism, and a sunshade based on the geographical position of the installation location, the orientation of the installation state, and the date and time. A control device mainly including a microcomputer that controls the rotation driving device so as to have an appropriate rotation angle according to the position of the device, and a solar cell including a solar cell that supplies power to the rotation driving device, the control device, and the like In a microcomputer built-in device composed of a driving-type solar lighting device, the output of the solar cell is changed according to a change in weather conditions (such as a cloud state or a state where falling leaves are placed on the lighting unit). When the power becomes insufficient to drive, it is determined to be a power failure, and when it becomes sufficient to drive the required mechanism, it is determined to be a power failure recovery. Power control apparatus according to any one of claims 1 to 7 that.