JP5034387B2 - Battery-powered alarm - Google Patents

Description

  The present invention relates to a battery-type alarm device that notifies the occurrence of a fire, a gas leak, or incomplete combustion.

Conventionally, battery-powered alarms (hereinafter abbreviated as battery-powered alarms) that detect the occurrence of fire, gas leakage, incomplete combustion, etc. have been sold for offices and detached houses.
In recent years, this battery-type alarm device has come to employ a lithium battery that is most suitable for extending its life, and can be used for a long time without replacing the battery.

  The battery-powered alarm device has an abnormal alarm function that detects the occurrence of fire, gas leaks, incomplete combustion, etc. and notifies the abnormality with an alarm sound, etc. Is provided with a warning sound or the like (hereinafter referred to as an undervoltage warning function). This undervoltage alarm function compares the current battery voltage with the battery voltage required to notify the occurrence of a fire, gas leak, incomplete combustion, etc. with an alarm sound, etc. It functions to sound an audible alarm, etc.

Examples of the undervoltage condition alarm function include the following.
Referring to the built-in clock of the alarm device (battery-type alarm device described above), for example, a predetermined timing such as a regular time or every hour is detected every day, and an operating state is assumed in the monitoring state of the alarm device at this timing. Then, the operating voltage of the battery in this operating state is calculated. Further, it is determined whether or not the calculated operating voltage is lower than a predetermined voltage necessary for the operation of the alarm device. If the calculated operating voltage is lower than the predetermined voltage, the operating voltage is reduced as the battery has run out. Notification is made (see Patent Document 1).
JP 2005-208807 A (paragraphs “0032”-“0034”, paragraphs “0073”-“0077”, FIGS. 6 and 12)

  As described above, the battery-type alarm device has a voltage shortage state alarm function for notifying the lack of voltage of the battery in use by an alarm sound or the like. And in order to detect the voltage shortage of the battery in use, the battery voltage at that time is measured every time the above function is executed.

However, since the battery voltage is measured by applying an alarm load between both terminals of the battery, the battery consumption per measurement of the battery voltage is large.
For example, if it is performed every hour as in the example of Patent Document 1, the battery is quickly consumed by itself.

For this reason, conventionally, the battery voltage is actually measured at long intervals, such as every other day, thereby suppressing the consumption of the battery used for the measurement of the battery voltage.
As a result, the battery consumption for battery voltage measurement has been kept low, but in exchange for this, when an occurrence of fire, gas leakage, incomplete combustion, etc. is detected, an alarm sound is generated due to insufficient battery voltage. Some problems such as not sounding.

  This is particularly likely to occur after an abnormal alarm function (specifically, after an alarm output such as an alarm sound output) in which the battery is exhausted severely. If the last alarm output that causes the battery to run out of voltage is performed during a period when the battery voltage is not regularly detected, the alarm cannot be output until the next detection timing of the battery voltage detection that is periodically performed. Will continue to use the vessel. That is, even if a fire, gas leak, incomplete combustion, etc. occur during this period, the battery type alarm cannot output an alarm, and the battery type alarm does not function as an alarm.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a battery type alarm device that can detect battery voltage shortage at an early stage.

In order to solve the above problems, the present invention is configured as follows.
One aspect of the battery type alarm device of the present invention is based on the premise that a warning is output when the battery is driven. At least immediately after the alarm is released, a voltage shortage state detecting means for detecting whether or not the battery is in a low voltage state is provided. It is comprised so that it may have.

In addition, it is desirable that the voltage shortage state detecting means further detects whether or not the battery is in a voltage shortage state at regular intervals.
The other one of the battery-type alarm devices according to the present invention is based on the assumption that the output voltage of the battery outputs an alarm by the control of the control circuit applied through the constant voltage circuit.
At least immediately after the alarm is released, a battery voltage acquisition unit that applies a pseudo maximum load to the output side of the constant voltage circuit and acquires a voltage generated on the input side of the constant voltage circuit, and the acquired voltage is determined by the control circuit Comparison determination means for comparing and determining whether or not the voltage is necessary for a future alarm output, and a signal indicating an insufficient voltage state of the battery when the acquired voltage is lower than a voltage necessary for the future alarm output. And an undervoltage state notification means for outputting.

  In addition, it is desirable that the battery voltage acquisition means applies a maximum load on the output side of the constant voltage circuit and acquires a voltage generated on the input side of the constant voltage circuit at regular intervals.

  In the present invention, the battery voltage is detected immediately after the alarm is released. For this reason, even when the periodic detection of the battery voltage is not performed for a while after the alarm is released, the detection can be performed immediately after the alarm is released.

  According to the present invention, the battery voltage can be detected immediately after the alarm is released. Then, when the battery is in an insufficient voltage state, the alarm can be output to the surroundings. Since detection is performed even after an alarm with a heavy alarm load, early detection of an insufficient voltage state is possible even if a fixed period of detection time does not come. In particular, if there is an alarm output that causes a battery voltage shortage, the battery shortage state can be detected immediately after the alarm output is released, so the period of time during which the battery is left in a low voltage state is greatly increased. The battery can be shortened and the battery can be replaced at an optimal timing to keep the battery-powered alarm device operating normally.

  In addition, since the battery voltage is detected immediately after the alarm is released, it is not necessary to set the battery voltage detection cycle at a constant cycle to a short cycle design in consideration of the alarm that operates irregularly. Therefore, it becomes possible to design a longer period for detecting the battery voltage at a constant period, and as a result, the battery life is increased.

Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.
FIG. 1 is a conceptual diagram of a battery-powered alarm device (hereinafter referred to as a battery-powered alarm device) according to the present invention.

  The battery-type alarm device 1 is an alarm device that detects and notifies the occurrence of fire, gas leakage, incomplete combustion, and the like. The battery type alarm device 1 includes a battery 10 and outputs a warning by, for example, sounding an alarm sound by driving the battery.

  The battery type alarm device 1 includes an abnormality detection means 12 for detecting the occurrence of fire, gas leakage, incomplete combustion, and the like, and when such an abnormality is detected, for example, an alarm sound is sounded as described above, or Alarm means 14 that outputs an alarm to the surroundings by displaying an alarm on the screen or the like, or notifying the state to the outside, and further, the voltage of the battery 10 used is insufficient by measuring the voltage of the battery 10 used. Insufficient voltage state detection means 16 for detecting whether or not the state is present is provided.

  This voltage shortage detection means 16 measures the voltage of the battery 10 used at least immediately after the alarm output of the warning means 14 is canceled, and detects whether or not the battery 10 is in a voltage shortage state. Note that the detection by the undervoltage condition detection means 16 is more preferably performed at a constant period in addition to the above detection timing.

  The “voltage shortage state” represents a state in which the battery voltage is lower than the voltage necessary for alarm output in the future. Furthermore, “voltage necessary for alarm output in the future” refers to a voltage that enables alarm output at least once within a predetermined period from the time of measurement of the battery voltage.

Further, the alarm means 14 provided in the battery-type alarm device 1 does not output an alarm only when an abnormality is detected as described above. In addition, the battery shortage state detection means 16 detects that the battery voltage is insufficient. An alarm is output even if it is detected.
(Example)
Examples of the battery type alarm device of the present invention will be described below.

FIG. 2 is an example of a circuit configuration of a battery-type alarm device including the above-described means.
The electromotive force symbol shown in the circuit of the present embodiment indicates the battery 10 that can be replaced or charged.

  Control of the entire battery type alarm device of this example is controlled by the control circuit 20 and operates with the power supplied from the battery 10. In this example, the output voltage V (+) of the battery 10 is applied to the control circuit 20 via the constant voltage circuit 22.

A pseudo load 24 and an ON / OFF switch 26 are connected in parallel with the control circuit 20 as viewed from the constant voltage circuit 22.
The control circuit 20 includes a storage unit 30 for storing various data and programs loaded in the control circuit 20, an abnormality detection unit (a fire detection unit for detecting the occurrence of a fire in this example) 32, and Alarm output unit 34 (in this example, an alarm sound output unit 34-1 for generating an alarm sound, an alarm display output unit 34-2 for displaying an alarm, and an alarm external output unit 34-3 for notifying the occurrence of an abnormality to the outside ) Is connected.

The battery 10 is a consumable battery such as a dry battery or a rechargeable battery.
The constant voltage circuit 22 is a circuit that stably supplies a voltage lower than the battery voltage to the control circuit 20, and is composed of a Zener diode or the like.

The pseudo load 24 is used to apply a pseudo maximum load to the output of the constant voltage circuit 22 and is constituted by a resistor having a resistance value corresponding to the maximum load.
The ON / OFF switch 26 is a change-over switch for causing a current to flow through or disconnecting the pseudo resistor 24, and is constituted by a transistor. When a HIGH level voltage is applied to the base of the transistor, a current flows between the collector and the emitter (switch is turned on), and a current flows through the pseudo resistor 24. Further, by switching the applied voltage to the LOW level, the switch is turned off so that no current flows to the pseudo resistor 24.

  The fire detection unit 30 includes a thermistor and the like, and is driven by the control circuit 20 at regular intervals. By this driving, ambient heat is sensed, and a signal is output to the control circuit 20 when the heat level exceeds a predetermined level due to the occurrence of a fire.

  Further, the fire detection unit 30 may be configured to detect photoelectrically. In this case, the light emitting element and the light receiving element are combined, and the light emitting element is caused to emit light at regular intervals from the control circuit 20 and the scattered light of the light is detected by the light receiving element. Normally, when smoke is generated by a fire, light emitted from the light emitting element is scattered and reflected by the smoke particles. The photoelectric fire detection uses the light scattering phenomenon at the time of the fire, and the intensity of the received light fluctuates due to the scattering of the light from the smoke particles, so the fire is detected when the intensity exceeds the specified value. A signal is output to the control circuit 20 by determining that it has occurred.

Needless to say, it may be configured to detect heat and smoke by combining them.
The storage unit 32 is a ROM, a RAM, or the like.

  The alarm output unit 34 performs various types of alarm processing based on the data output from the control circuit 20 (for example, sounds an alarm sound, displays an alarm on a display screen, or transmits an alarm notification externally). In this example, when the alarm is released, an alarm release signal is output to the control circuit 20. Although the alarm release signal output to the control circuit 20 will be described later, its output time is adjusted so that it is output until the signal is detected by the control circuit 20.

  The control circuit 20 is a circuit that controls the entire battery-powered alarm as described above. In this example, the control circuit 20 includes a CPU (central processing unit). Furthermore, an internal counter and a drive unit that drives the fire detection unit 30 at regular intervals after power-on are provided.

  In the present control circuit 20, various functions are realized by executing instructions (software programs) in a predetermined order in the CPU and controlling the above-described units (including the drive unit). The software program is a program or data for realizing various functions, and is stored in the storage unit 32. When the function is realized, the program and data are loaded from the storage unit 32 into the internal storage unit included in the control circuit 20, and instructions are executed by the CPU in order of steps.

  The battery-type alarm device of this example instructs the fire detection unit 30 to measure the occurrence of a fire as one of the various functions described above, and outputs from the fire detection unit 30 when a fire occurrence is detected. A function (first function) for executing an alarm output process using a detected signal as a trigger is provided. In this alarm output process, a command signal for outputting an alarm is output to the alarm output unit 34.

  Moreover, as another one, it has a function (second function) for monitoring the voltage value of the battery being used and executing the alarm output process when the battery is in an insufficient voltage state. .

  In the monitoring method described above, a HIGH level signal is output to the base of the transistor 26 (switch ON) to cause a current to flow through the resistor 24, and a pseudo maximum load is generated on the output side of the constant voltage circuit 22. At the same time, the output voltage of the battery 10 at this time (this output voltage is an analog value) is taken in as a digital value via the A / D converter 200 configured in the control circuit 20 (monitoring process).

These functions can be realized, for example, by allowing the CPU to always execute the main routine process after turning on the power.
The first function is, for example, set so that the internal counter is initialized (count value is set to 0) in the first step of the main routine, and this is performed only once at the start of the main routine. It can be realized by making it execute. In this case, when the battery-type alarm device is powered on and the main routine program is started, the first step is executed by the CPU only at the time of the start-up, and the value of the internal counter is initialized to zero. After that, the internal counter starts counting up, and when the value reaches a predetermined count number, the value is reset. Further, a signal is output to the drive unit together with the reset of the value in the internal counter, and the fire detection unit 30 is driven by the drive unit for a predetermined time. Thereby, the fire detection part 30 performs the process which outputs a signal to the control circuit 20, for example, when the sensed heat is more than a predetermined level during the drive. In the main routine, after the power is turned on, the signal output from the fire detection unit 30 is monitored, and when the signal output is detected, an alarm output command signal is output to the alarm output unit 34.

  The second function can be realized, for example, by always measuring the timing for detecting the battery voltage in the main routine. This second function will be described in detail below.

FIG. 3 is a processing flow (control processing flow for detecting a battery voltage shortage state) of the portion realizing the second function.
In this example, steps S1 and S2 are included in the main routine process, and steps after step S3 are executed as a subroutine process.

  After the main routine processing program is executed, in the first processing for realizing the second function, first, it is determined whether or not it is the timing for regularly detecting the battery voltage (first battery voltage detection timing). Perform (S1). In this determination processing, for example, the counter value of the internal counter is read, and when the counter value is a predetermined value, it is determined that it is a periodic detection timing, and the other is determined not to be a periodic detection timing.

  As a specific example, an area for setting a second count value for determining the regular timing is provided in the internal counter. This second counter value is first initialized to zero. Then, when the count value of the internal counter is reset to 0, the second counter value is incremented by one, and when the later-described periodic detection is performed, the second counter value is reset to 0. Under such a configuration, in the determination process, when the second counter value of the internal counter is read and the counter value is a predetermined value (or includes a case where the counter value is exceeded), the periodic detection timing It is determined that the other is not the periodic detection timing.

  If it is determined in step S1 that it is not the periodic detection timing, then it is determined whether or not it is a voltage detection timing after alarm output (second battery voltage detection timing) (S2). This determination process is performed by detecting an alarm release signal from the alarm output unit 34. For example, when an alarm release signal is detected from the alarm output unit 34, it is determined that it is the second battery voltage detection timing, and it is determined that the other is not the detection timing. In this example, when the alarm release signal is detected, the output of the alarm release signal is stopped by sending a signal to the alarm output unit.

If it is determined in this process that it is not the second battery voltage detection timing, a main routine process (not shown) following step S2 is performed without performing a subroutine process described later.
On the other hand, if it is determined in step S1 that the first battery voltage detection timing is reached, or if it is determined in step S2 that the second battery voltage detection timing is reached, then the sensor drive is continued. Timing determination processing is performed (S3). This determination process is a process for determining whether or not the fire detection unit 30 is in a driving state. This determination process is performed, for example, by checking the value of the internal counter. The count value in the drive state of the fire detection unit 30 can be acquired by checking in advance the count value counted up by the internal counter between the start and end of the drive of the fire detection unit 30. For this reason, it is possible to determine whether or not the fire detection unit 30 is in a driving state by checking the count value.

Here, when the fire detection unit 30 is in a drive state, that is, when a fire detection process is being performed, the fire detection unit 30 is kept in a loop until the drive state is released.
Then, when the fire detection unit 30 is not in the driving state or when the driving state is released, the battery voltage monitoring process is performed. However, at this time, the alarm output unit 34 does not output an alarm.

  In this battery voltage monitoring process, first, the pseudo load 24 is turned on (S4). Specifically, a HIGH level voltage is applied to the base of the transistor 26 to switch on the transistor 26.

  As a result, a current flows through the pseudo load 24 and a maximum load is applied to the constant voltage circuit 22 in a pseudo manner. At this time, if the battery is new, a sufficient voltage is generated between both terminals. On the other hand, when the battery is exhausted, a sufficient voltage cannot be generated between the two terminals, resulting in a voltage drop.

In this example, after the pseudo load 24 is turned on, it waits for 100 ms (S5).
This is because the response curve of the battery voltage becomes unstable due to the ambient temperature or the like immediately after the pseudo load 24 is turned on, and an accurate value of the battery voltage can be read by waiting for about 100 ms.

  Then, the battery voltage of the battery 10 is read via the A / D converter 200 (S6), and the HIGH level voltage applied to the base of the transistor 26 is immediately switched to the LOW level voltage to turn off the transistor 26. (S7).

Then, the battery voltage value read in step S6 is compared with a predetermined threshold value to determine whether or not the battery voltage is insufficient (S8).
In this determination process, for example, the battery voltage is determined to be sufficient when the value of the read battery voltage is greater than a predetermined threshold, and the battery voltage is determined to be insufficient when the value is equal to or less than the threshold.

  The predetermined threshold value can be obtained in advance by simulation or the like. For example, by measuring the relationship between the elapsed time when battery-operated alarms are normally used and the rate of decrease in battery voltage, the relationship between the amount of decrease in battery voltage when alarm output is performed in the future, etc. Determine the optimal value based on. This value may be a fixed value or a value that varies depending on the use situation.

If it is determined that the battery voltage is sufficient, the battery voltage monitoring process is terminated, that is, the subroutine process is exited, and a main routine process (not shown) subsequent to step S2 is performed.
On the other hand, if it is determined that the battery voltage is insufficient, a battery voltage insufficient condition alarm is set (S9). For example, an area indicating whether or not the battery voltage is insufficient is created, and a flag is set in the area.

Then, the battery voltage monitoring process is terminated, that is, the subroutine process is exited, and a main routine process (not shown) following step S2 is performed.
In the main routine process (not shown), the process of determining whether or not the flag is set is repeatedly performed by looking at the area of whether or not the battery voltage is insufficient. If it is determined that the flag is set in this determination process, a routine process (alarm routine process) is performed to output an alarm output command signal to the alarm output unit 34 and remove the flag set in the area. become.

  The main routine process (not shown) is repeatedly executed immediately after the battery-type alarm device is turned on, and the process from the above-described step S1 and the determination process of the battery voltage insufficient state flag are repeated.

FIG. 4 is an example of a relationship diagram between various processing timings and battery consumption.
FIG. 5A is a graph showing the relationship between various processing timings and current consumption.
FIG. 4B is a graph of the time change of the battery voltage when the maximum load is applied.

In addition, the timing of the time axis of each figure shall be in agreement.
FIG. 2A shows a time-varying drive state of the fire detection unit 30 as a graph of changes in current consumed at that time. The small convex part shown by the rectangular wave shape in the figure is a consumption current change consumed by one driving of the fire detection unit 30 from the reference horizontal line (the level of current consumption normally consumed) of the convex part. Represents. Moreover, the large convex part with a narrow width | variety represents the consumption current change consumed in the battery voltage measurement process which applies maximum load artificially. And the wide convex part with a wide width | variety represents the consumption current change consumed by an alarm output process.

  In the case of this configuration, it can be seen that the current consumption when the fire detection unit 30 is driven once is small. On the other hand, it can be seen that the battery voltage measurement process and the alarm output process are subjected to a maximum load on the circuit and consume a large amount of current. In particular, in the alarm output process, an alarm continues to be output for a while, so that a maximum load is applied to the circuit during that time, and a large amount of current is consumed.

  In the figure, each detection timing is indicated by an upward arrow. The detection timing (sensing timing) of the fire detection unit 30 is indicated by a broken line arrow, and the first battery voltage detection timing is indicated by a one-dot chain line arrow. The second battery voltage detection timing is indicated by a solid arrow.

FIG. 4B shows the change in battery voltage at this time.
In the figure, it can be seen that the battery voltage is greatly reduced by the alarm output process.
In the same figure, the threshold value (expected value) of the battery voltage indicating the battery shortage state and the voltage at which the alarm output cannot actually be operated are shown superimposed. In the case of this example (in the case of A), the battery voltage does not fall below the expected value after the alarm output process until the next first battery voltage detection timing. Although not clearly shown in the figure, the battery voltage is sufficient to continue alarm output to some extent during that time. That is, the battery voltage value at that time is equal to or higher than the battery voltage value necessary for future alarm output. This can be predicted in advance by simulation or the like. For this reason, in this example, the alarm output is not performed after the battery voltage detection process at the second battery voltage detection timing.

  As shown in FIG. 6A, the sensing timing has a short cycle, and the fire detection process is repeatedly performed in that cycle. On the other hand, the first battery voltage detection timing has a longer cycle (for example, 26 hours), and the battery voltage detection process is repeatedly performed in that cycle. Further, the second battery voltage detection timing is set after the alarm output is performed (it is desirable to be set immediately after the alarm output is performed as much as possible). Detection processing is performed. During the driving of the fire detection unit 30, the battery voltage detection process is not performed until the driving is completed, so that the first and second battery voltage detection timings in FIG. It is a little later in time than that.

  In this example, after a fire occurrence is detected at a certain sensing timing, a warning is output at a sensing timing (time t) after a predetermined period. The shorter the delay time from the occurrence of this fire to the warning output, the better.

  Further, in this example, as described above, the case where the battery voltage shortage state is not detected in the battery voltage detection process at the second battery voltage detection timing is shown. However, for example, in the case of the battery voltage change graph shown as another example (in the case of B) in FIG. 5B, when the value is lower than the expected value after the alarm is output, the next first battery voltage detection timing Even if the battery voltage can be detected, the battery voltage is not sufficient to output an alarm, so an alarm cannot be output even if a fire or the like is detected. For this reason, the case B is detected as a battery voltage shortage state, and a warning is output at the earliest possible timing after the second battery voltage detection timing.

Also, when a fire is detected by the fire detection process, an alarm is output with priority over other processes.
Further, in the present embodiment, a configuration for detecting the occurrence of fire from smoke or heat (fire detection unit 30) is taken as an example as an abnormality detection means. However, it goes without saying that the abnormality detecting means is configured to detect, for example, gas leakage or incomplete combustion (that is, generation of carbon monoxide), a composite type thereof, and other abnormalities. The operation and effect described above may occur in all battery-powered alarm devices.

  As described above, in this battery type alarm device, the battery voltage is detected after the alarm is released (preferably immediately after that). For this reason, even when the periodic detection of the battery voltage is not performed for a while after the alarm is released, the detection can be performed immediately after the alarm is released.

  Therefore, the battery voltage is detected immediately after the alarm is released, and when the battery is insufficient, the state can be output as an alarm. When there is an alarm output that causes a battery voltage shortage, the voltage shortage can be detected immediately after the alarm is released. Therefore, the period during which the voltage shortage state is neglected can be greatly shortened, and the battery replacement of the battery type alarm device can be performed at an optimal timing.

It is a conceptual diagram of the battery-type alarm device which concerns on this invention. It is an example of the circuit structure of a battery-type alarm device. It is a control processing flow for detecting a battery voltage shortage state. It is an example of the relationship figure of the timing of various processes, and battery consumption.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Battery type alarm device 10 Battery 12 Abnormality detection means 14 Alarm means 16 Undervoltage state detection means

Claims (8)

A battery-type alarm device that periodically drives a detection unit having a function of detecting an abnormal state and outputs an alarm by battery driving when an abnormal state is detected ,
An insufficient voltage state detection means for detecting whether or not the battery is in an insufficient voltage state at least immediately after the alarm is released and the detection unit is not in a driving state ;
Battery-powered alarm device, characterized in that it comprises a.   In addition, the voltage shortage state detection means is immediately after the alarm is released, and when the detection unit is in a drive state, the battery is in a low voltage state immediately after the drive state of the detection unit is released. The battery-operated alarm device according to claim 1, wherein it is detected whether or not. The under-voltage state detecting means, battery-powered alarm device according to claim 1 or 2 further said battery when the periodic intervals in addition characterized by the Turkey detect whether the voltage insufficiency. The battery type alarm device according to claim 3, wherein the constant cycle is a timing when the detection unit is not in a driving state. Battery type that outputs a warning when an abnormal state is detected by periodically driving a detector with a function to detect an abnormal state under the control of a control circuit to which the output voltage of the battery is applied via a constant voltage circuit An alarm device,
The control circuit includes:
A battery that applies a maximum load on the output side of the constant voltage circuit and obtains a voltage generated on the input side of the constant voltage circuit at least immediately after the alarm is released and the detection unit is not in a driving state Voltage acquisition means;
Comparison determination means for determining whether or not the acquired voltage is equal to or higher than a voltage necessary for a future alarm output by the control circuit;
An insufficient voltage state notification means for outputting a signal indicating an insufficient voltage state of the battery when the acquired voltage is lower than a voltage required for the future alarm output;
Battery-powered alarm device, characterized in Rukoto equipped with.   In addition, the battery voltage acquisition means is immediately after the alarm is released, and when the detection unit is in the drive state, immediately after the drive state of the detection unit is released, the output side of the constant voltage circuit The battery-type alarm device according to claim 5, wherein a pseudo load is applied to the battery and a voltage generated on an input side of the constant voltage circuit is acquired. The battery voltage acquisition means includes
In addition, at a certain period, a pseudo load is applied to the output side of the constant voltage circuit and the voltage generated on the input side of the constant voltage circuit is acquired.
The battery-type alarm device according to claim 5 or 6 , wherein The battery type alarm device according to claim 7, wherein the constant cycle is a timing that does not overlap a timing at which the detection unit is in a driving state.