JP2011086217A - Alarm - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an alarm which can suppress the malfunction of a control circuit due to occurrence of dew condensation in a casing. <P>SOLUTION: A fire alarm 100 includes a control part 10, a dew condensation detection circuit 70 and the like. When a dew condensation detection signal received from the dew condensation detection circuit 70 is in a dew condensation decision level, the control part 10 suspends a fire or abnormality determination operation based on detection outputs of a smoke sensor 20, a heat sensor 30, and a battery voltage monitoring circuit 60. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an alarm device, and more particularly to an alarm device capable of preventing malfunction of a control circuit when dew condensation occurs in a housing.

  As a conventional technique, for example, “When an elapsed time since the start of use is updated and stored in a non-volatile memory and a use period that is an operation guarantee period of, for example, 5 years is monitored, a battery is detected and an alarm is issued. When the user replaces the battery, the elapsed time from the start of use is stored in the non-volatile memory and does not disappear even if the battery is replaced. When the operation is completed, the same alarm as when the low battery level is detected is issued, and a long-term use can prevent dust from adhering and accumulating and preventing the use of fire detection from being guaranteed. (For example, refer to Patent Document 1).

JP 2007-011829 A (page 4)

  The alarm device disclosed in Patent Document 1 has a problem in that when dew condensation occurs on a printed circuit board, the operation of the CPU becomes unstable and normal fire monitoring operation cannot be guaranteed.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide an alarm device capable of suppressing malfunction due to condensation.

  An alarm device according to the present invention includes a state detection unit, a state determination unit that determines a state based on an output signal of the state detection unit, a control unit that outputs an alarm based on a determination result of the state determination unit, A dew condensation detection unit that detects the occurrence of dew condensation and transmits a dew condensation detection signal to the control unit; and when the dew condensation detection signal received from the dew condensation detection unit is out of a predetermined range, The determination operation of the state determination unit is suspended.

In the alarm device according to the present invention, the dew condensation detection unit has a resistance unit in which a plurality of resistors having high resistance values are connected in series, and the resistance unit is supplied with a stable voltage via a constant voltage circuit. The intermediate potential is transmitted to the control unit as the dew condensation detection signal.
Moreover, the alarm device which concerns on this invention WHEREIN: The said resistance part is provided with the switch connected in series between these resistors, and the said control part turns on the said switch intermittently.
Further, in the alarm device according to the present invention, the control unit stores the number of times the determination operation of the state determination unit is suspended or the determination content thereof in a storage unit.

  In the present invention, when the dew condensation occurs inside the housing of the alarm device, the determination operation of the state determination unit is suspended, so that a malfunction such as a fire alarm can be suppressed.

In the present invention, the dew condensation detection unit has a resistance unit in which a plurality of resistors having a high resistance value are connected in series. The resistance unit is supplied with a stable voltage via a constant voltage circuit, and an intermediate potential thereof is obtained. The dew condensation detection signal is sent to the control unit as a dew condensation detection signal, and the dew condensation detection unit is realized with a simple configuration and is supplied with a stable voltage, so that the dew condensation detection signal is not affected by fluctuations in battery voltage. .
Further, in the present invention, the resistance unit includes a switch connected in series between a plurality of resistors, and the switch is intermittently turned on. Therefore, the operation of the dew condensation detection unit is intermittently performed. Power saving is achieved.
Further, in the present invention, the number of times the determination operation of the state determination unit is suspended or the determination content is stored in the storage unit, so that the occurrence state of condensation can be grasped.

It is a functional block diagram which shows the circuit structure of the fire alarm device 100 which concerns on Embodiment 1 of this invention. It is a block diagram which shows the internal structure of the control part 10 which concerns on Embodiment 1 of this invention. 1 is a circuit schematic diagram of a dew condensation detection circuit 70 according to Embodiment 1 of the present invention. It is a flowchart regarding operation | movement of the dew condensation detection circuit 70 which concerns on Embodiment 1 of this invention.

Embodiment 1 FIG.
Hereinafter, in the first embodiment, a case where the present invention is applied to a fire alarm device driven by a battery will be described as an example.
FIG. 1 is a functional block diagram showing a circuit configuration of a fire alarm 100 according to Embodiment 1 of the present invention.
In FIG. 1, the fire alarm 100 includes a control unit 10, a battery 1, a constant voltage circuit 2, an inspection switch 3, an EEP-ROM 4, a smoke detection unit 20 and a heat detection unit 30 that function as a state detection unit. An alarm sound control circuit 40, an indicator lamp circuit 50, a battery voltage monitoring circuit 60 that functions as a voltage monitoring unit, and a dew condensation detection circuit 70 that functions as a dew condensation detection unit.

  The control unit 10 is configured by, for example, a one-chip microcomputer or the like, and performs overall control of the fire alarm device 100. The control unit 10 periodically takes in signals from each internal circuit and performs processing according to the signals. For example, when the control unit 10 takes in a signal (fire detection signal) from the light receiving amplifier 23 of the smoke detection unit 20, it is determined whether an alarm sound is necessary based on the fire detection signal. When the control unit 10 captures the fire detection signal and determines that the alarm sound is necessary, the control unit 10 outputs the sound data of the alarm sound to the alarm sound control circuit 40.

  The internal configuration of the control unit 10 will be described later with reference to FIG. 2, but the control unit 10 stops the supply of the clock signal from the main clock oscillation unit 16 when waiting for the abnormality monitoring operation or the fire monitoring operation, It operates in a sleep mode that operates only by supplying a clock signal from the clock oscillator 17. However, when there is a periodic timer interrupt, inspection switch interrupt, or the like, the control unit 10 stops the sleep mode and supplies the clock signal of the main clock oscillation unit 16 to perform a necessary operation.

  The constant voltage circuit 2 supplies the power supply voltage of the battery 1 to the control unit 10 or the like as a predetermined constant voltage power supply (for example, a voltage of about 2.3 V). The inspection switch 3 receives a pressing operation by a user such as a resident. When the inspection switch 3 is pressed, the control unit 10 captures a pressing signal of the inspection switch 3 and determines whether or not the input of the inspection switch 3 is confirmed. When the control unit 10 determines that the input of the inspection switch 3 is confirmed, the control unit 10 transmits a signal for starting an inspection related to an operation such as an alarm sound or an indicator light. The EEP-ROM 4 stores programs executed by the calculation unit 11 of the control unit 10 and various data (fire threshold, sensor abnormality threshold, battery exhaustion abnormality threshold, state determination counter threshold, condensation determination counter accumulated value, and the like).

  The smoke detection unit 20 includes an infrared LED 24 that is a light emitting element, and an infrared LED drive circuit 21 that supplies a current pulse to the infrared LED 24 when receiving a light emission control pulse from the control unit 10. Further, the smoke detector 20 has a photodiode current voltage having a light receiving element such as a photodiode (PD) that receives scattered light generated by smoke particles by light emitted from the infrared LED 24 to the smoke detector (not shown). A conversion circuit 22 is provided, and the photodiode current-voltage conversion circuit 22 receives scattered light generated by the emission of the infrared LED 24. The photodiode current / voltage conversion circuit 22 converts the current obtained based on the amount of scattered light received by the light receiving element into a voltage. The output level of the voltage is amplified with a predetermined gain in the light receiving amplifier 23 and transmitted to the control unit 10.

  The heat detection unit 30 includes a temperature sensor that includes a fixed resistor 31 and a thermistor 32. An intermediate potential between the fixed resistor 31 and the thermistor 32 is an output terminal of the heat detection unit 30, and a temperature detection signal is transmitted to the control unit 10 via the output terminal. The thermistor 32 has a temperature characteristic that its resistance value varies according to the environmental temperature. Since the temperature characteristic of the thermistor 32 is linearized by the compensation fixed resistor 31, a detection voltage (temperature information) corresponding to the environmental temperature is input to the output terminal. Only one of the smoke detection unit 20 and the heat detection unit 30 may be provided.

  The alarm sound control circuit 40 includes an audio D / A converter 41 having a low-pass filter, an audio amplifier 42 and a speaker 43 as sounding components. The low-pass filter plays a role of adjusting the audio data transmitted from the control unit 10 in advance to a frequency band that is easy for the user to listen to.

  In the alarm sound control circuit 40, the audio data (digital signal) input from the control unit 10 is converted into an audio signal (analog signal) by the audio D / A converter 41 and output through a low-pass filter. . Then, a volume control signal is transmitted from the control unit 10 to the audio amplifier 42, and the audio amplifier 42 adjusts the amplification degree of the audio signal (analog signal). In the speaker 43, the sound signal amplified by the sound amplifier 42 is converted into sound (sound) and output.

  The indicator lamp circuit 50 displays the state of the fire alarm 100 on the red LED 52 connected to the confirmation lamp drive circuit 51. Note that the fire alarm 100 is in a state where the fire detection operation is normal (the fire is not detected and there is no abnormality in the remaining battery level or sensor device), or the remaining battery level. There may be an abnormality due to a drop, an abnormality due to a device such as a sensor failure, or a fire is detected and an alarm is output. The red LED 52 is provided in the housing of the fire alarm 100. In addition, although red LED52 is used as an indicator lamp, the kind and number are not specifically limited.

  The battery voltage monitoring circuit 60 detects a voltage applied to the control unit 10 and outputs a battery voltage detection signal corresponding to the detected voltage to the control unit 10. The battery voltage monitoring circuit 60 outputs a battery voltage detection signal to the control unit 10 when it detects that the remaining battery level has dropped or has fallen below the threshold value for running out of the battery, and the control unit 10 and the alarm sound control circuit 40 A control signal is transmitted to the indicator lamp circuit 50.

  The dew condensation detection circuit 70 has a very small size (for example, 1.0 mm × 0.5 mm) and a resistance unit 71 in which two chip resistors having a high resistance value (for example, 1 MΩ to 5 MΩ) are connected in series. The output signal of the intermediate potential is A / D converted by the A / D converter 15 and transmitted to the control unit 10 as a dew condensation detection signal (see FIG. 3). The high potential side of the resistance portion 71 is connected to the constant voltage circuit 2 that does not depend on the battery voltage, and the low potential side of the resistance portion 71 is grounded. When a battery device is used as the power source, a switch 72 may be provided so as to be able to be turned on / off in order to suppress current consumption.

FIG. 2 is a block diagram illustrating an internal configuration of the control unit 10. Based on FIG. 2, the main internal structure of the control part 10 is demonstrated.
The control unit 10 includes a calculation unit 11 that performs overall control of the operation of the fire alarm device 100, a ROM 12, a RAM 13, and the like as main circuits.

  The calculation unit 11 performs an abnormality monitoring operation and a fire monitoring operation for determining the occurrence of an abnormality and the occurrence of a fire based on various data transmitted from each circuit described above. That is, the calculation unit 11 serves as a state determination unit. The calculation unit 11 includes a CPU (central processing unit), an MPU (ultra-compact processing unit), and the like. The ROM 12 stores programs executed by the calculation unit 11 and various data. The RAM 13 includes a state determination counter 81 for determination in the determination operation of occurrence of abnormality or fire by the control unit 10, and a condensation determination counter 82 for calculating the cumulative number of times that the control unit 10 has determined that condensation has occurred. The arithmetic unit 11 functions as a memory such as a work memory or a page memory that temporarily stores various data when executing the program.

  A timer unit 14, an A / D converter 15, a main clock oscillation unit 16, a sub clock oscillation unit 17, and an interface unit 18 are connected to the calculation unit 11 via a bus.

  The timer unit 14 measures time. For example, the timer unit 14 measures the start timing of the abnormality monitoring operation and the fire monitoring operation that are periodically performed by the control unit 10. That is, an interrupt is periodically generated at the timing counted by the timer unit 14, and the arithmetic unit 11 is operated by the interrupt. In addition, the timer unit 14 measures the time from when the alarm sound is stopped, or measures the cycle of the blinking state of the red LED 52.

  The A / D converter 15 receives an analog signal transmitted from the smoke detection unit 20 or the heat detection unit 30, converts the information into a detection level, and supplies the detection level to the calculation unit 11. The calculation unit 11 determines whether an abnormality or a fire has occurred in the fire alarm device 100 based on this detection level.

  The main clock oscillating unit 16 supplies a clock signal for executing an abnormality monitoring operation or a fire monitoring operation to the arithmetic unit 11 when a periodic timer interruption or a check switch operation is performed. When the clock signal from the main clock oscillation unit 16 is supplied, the calculation unit 11 collects data from each circuit, for example, fire detection data, battery voltage data, and the like, and an abnormality occurs based on the data. An abnormality monitoring operation and a fire monitoring operation are performed to determine the presence or absence of a fire or the occurrence of a fire. When the abnormality monitoring operation and the fire monitoring operation are finished, the arithmetic unit 11 switches the supply of the clock signal from the main clock oscillation unit 16 to the supply of the clock signal from the sub clock oscillation unit 17 and operates in the sleep mode.

  The sub clock oscillator 17 supplies a clock signal having a frequency lower than that of the clock signal supplied from the main clock oscillator 16 to the arithmetic unit 11. That is, the sub-clock oscillating unit 17 supplies a clock signal that causes the computing unit 11 to operate with a low current consumption (sleep mode).

  The interface unit 18 has a function of connecting each circuit constituting the fire alarm device 100 to the control unit 10. That is, each circuit constituting the fire alarm device 100 is connected to the control unit 10 via the interface unit 18 and inputs / outputs various data.

Next, the operation of the fire alarm 100 will be described. Here, a case where smoke is detected to determine whether or not a fire has occurred will be described as an example.
The fire alarm 100 sets the power supply voltage supplied from the battery 1 to a predetermined constant voltage (for example, a voltage of about 2.3 V) stabilized by the constant voltage circuit 2 and the constant voltage power is supplied to the control unit 10. The The fire alarm device 100 executes a fire monitoring operation and an abnormality monitoring operation at a predetermined cycle timed by the timer unit 14 included in the control unit 10.
Next, the control unit 10 supplies a light emission control pulse to the infrared LED drive circuit 21 to cause the infrared LED 24 to emit light with a predetermined pulse width and a predetermined cycle.

  The light receiving element of the photodiode current-voltage conversion circuit 22 is not arranged on the optical path of the infrared LED 24, and the light of the infrared LED 24 does not reach the light receiving element directly. However, when smoke generated by a fire or the like is interposed between the light receiving element and the infrared LED 24, the light of the infrared LED 24 is scattered by the smoke particles, and the light receiving element receives the scattered light. .

  For the above reason, when no smoke is generated, the light emitted from the infrared LED 24 hardly reaches the light receiving element. That is, since the signal amplified by the light receiving amplifier 23 is below a predetermined reference value (fire occurrence level), a signal for operating the alarm sound control circuit 40 and the indicator lamp circuit 50 is output from the control unit 10. Not. Therefore, the alarm sound control circuit 40 does not sound an alarm sound, and the indicator light circuit 50 does not cause the red LED 52 to indicate that a fire has occurred.

  When smoke is generated, the light emitted from the infrared LED 24 is scattered by the smoke particles, and the scattered light reaches the light receiving element. That is, since the signal amplified by the light receiving amplifier 23 is equal to or greater than a predetermined reference value, the control unit 10 determines that a fire has occurred and operates the alarm sound control circuit 40 and the indicator lamp circuit 50. Output a signal. Then, the alarm sound control circuit 40 sounds an alarm sound, and the indicator light circuit 50 causes the red LED 52 to display a fire.

  In the control unit 10, the analog signal amplified by the light receiving amplifier 23 is converted into a detection level by the A / D converter 15 and input to the calculation unit 11. The calculation unit 11 to which this detection level is input stores this detection level in the RAM 13 as fire detection data. Then, the calculation unit 11 determines whether or not a fire has occurred depending on whether or not the fire detection data stored in the RAM 13 is equal to or greater than a predetermined reference value set in advance. Therefore, the calculation unit 11 and the RAM 13 have a function as a state determination unit.

  When the calculation unit 11 determines that no fire has occurred, the operation unit 11 returns to the operation mode of the sleep mode. On the other hand, when the calculation unit 11 determines that a fire has occurred, the alarm sound control circuit 40 sounds an alarm sound, and the indicator lamp circuit 50 causes the red LED 52 to display a fire.

Next, the fire monitoring operation and the abnormality monitoring operation in the determination of the occurrence of condensation of the alarm device according to the first embodiment will be described.
Here, in the fire monitoring operation and the abnormality monitoring operation by the smoke detection unit 20 and the heat detection unit 30, each measurement value (detection level) exceeds the fire threshold or the sensor abnormality threshold every predetermined time (for example, every 4 seconds). It is determined whether or not.
In addition, in the abnormality monitoring operation by the battery voltage monitoring circuit 60 at predetermined time intervals (for example, at intervals of 1 minute), it is determined whether or not the measured value of the battery voltage exceeds the battery depletion threshold value, and the dew condensation monitoring circuit 70 performs the dew condensation monitoring. In operation, whether or not it is at the dew condensation determination level, that is, whether or not the dew condensation detection signal fluctuates and deviates from the predetermined range (greater than the upper limit value of the normal range or less than the lower limit value of the normal range in the dew condensation determination). to decide. This is due to the fact that the dew condensation detection signal slightly increases or decreases from the almost constant value during normal operation due to the occurrence of dew condensation.
Here, taking into account the battery life, the cycle of the judgment operation for detecting battery exhaustion or condensation is longer than the cycle of the fire monitoring operation of the sensor unit, but at the same cycle as the fire monitoring operation or shorter than the cycle of the fire monitoring operation. A determination operation for battery exhaustion or condensation detection may be performed, and the cycle of each operation is set as appropriate.

A fire or abnormality state determination counter 81 that counts the number of times each measured value exceeds a fire threshold, a sensor abnormality threshold, or a battery exhaustion abnormality threshold, and when any of the state determination counters 81 reaches a predetermined value, Performs an alarm or sound alarm by fire or abnormality confirmation process.
In addition, a dew condensation determination counter 82 that counts the number of times that the dew condensation detection signal fluctuates and deviates from the predetermined range is provided.

  When the condensation detection signal fluctuates and falls outside the predetermined range, the value of the condensation determination counter 82 is increased by +1, while the value of each state determination counter 81 is such that each measured value exceeds the fire threshold or abnormal threshold Even if it is not exceeded, it is held and the previous value is maintained.

  Thereby, the fire alarm device 100 does not malfunction such as a fire alarm when dew condensation is detected, and can reliably grasp the number of times it is determined that dew condensation occurs. Further, it is possible to efficiently investigate the fire alarm device 100 installed at the site where condensation is estimated to occur, and to verify whether the required specifications based on the configuration of the condensation determination circuit 70 are appropriate.

  FIG. 4 is an example of a flowchart of the fire monitoring operation and the abnormality monitoring operation in the determination of the occurrence of condensation of the alarm device according to the first embodiment. First, the control unit 10 performs a fire monitoring operation and an abnormality monitoring operation by the smoke detection unit 20, the heat detection unit 30, and the battery voltage monitoring circuit 60 at every predetermined time, and performs a monitoring operation by the dew condensation detection circuit 70, respectively. The detection signal is received. Next, the control unit 10 detects a fire, smoke, temperature sensor abnormality, or battery exhaustion abnormality by detecting each received detection signal (step S1). The measured value based on the signal is stored in the RAM 13 (step S2). Next, the measurement value based on the dew condensation detection signal of the dew condensation detection circuit 70 is stored in the RAM 13 (step S3).

  Next, when it is determined that the measurement values measured by the smoke detection unit 20, the heat detection unit 30, and the battery voltage monitoring circuit 60 exceed the fire threshold, the sensor abnormality threshold, or the battery exhaustion abnormality threshold (step S4; Yes) Subsequently, it is determined whether or not the measurement value measured by the dew condensation detection circuit 70 is at the dew condensation determination level (out of a predetermined range in the dew condensation determination) (step S5).

Here, the measurement value by the dew condensation detection circuit 70 is demonstrated using FIG.
When the measurement value obtained by A / D converting the output signal transmitted from the dew condensation detection circuit 70 is the dew condensation determination level (out of a predetermined range in dew condensation detection), the control unit 10 Judgment such as fire or running out of battery is suspended (see step S9 and step S16 in FIG. 4). The measurement value by the dew condensation detection circuit 70 shows a substantially constant value at the normal time when dew condensation does not occur. That is, since the output of the intermediate potential of the resistance unit 71 is a constant value applied to the fixed resistor, the output becomes a constant value even if A / D conversion is performed.

  However, when dew condensation occurs on the electronic circuit board provided with the dew condensation detection circuit 70, the dew condensation affects the impedance of the resistance portion 71 of the dew condensation detection circuit 70. Therefore, the measured value obtained by A / D converting the intermediate potential of the resistance unit 71 varies with time (see FIG. 3). Further, the number of times that the dew condensation determination is performed is written as a cumulative value in the dew condensation determination counter of the EEP-ROM 4 every predetermined time. The state information may be written.

In FIG. 4, when the measurement value measured by the dew condensation detection circuit 70 is not at the dew condensation determination level (within a predetermined normal range in the dew condensation determination) (step S5; No), the control unit 10 determines whether the fire threshold or the sensor abnormality threshold is present. Alternatively, it is determined that the battery exhaustion abnormality threshold has been exceeded, and the value of the state determination counter 81 corresponding to a fire or abnormality is increased by +1 (step S6).
When the value of each state determination counter 81 does not exceed the fire determination counter value A (for example, A = 1) or the abnormality determination counter value B (for example, B = 3) (step S7; No), the operation ends. On the other hand, when the value of each state determination counter 81 exceeds the fire determination counter value A or the abnormality determination counter value B (step S7; Yes), the control unit 10 performs an indicator lamp or sound by a fire or abnormality determination process. (Step S8). Then, the operation ends.

Returning to step S5, when the measurement value by the dew condensation detection circuit 70 is at the dew condensation determination level (out of the predetermined range in the dew condensation determination) (step S5; Yes), the control unit 10 causes the rapid measurement value due to dew condensation. It is determined that a change has been detected, the value of each state determination counter is suspended without being incremented by +1, and the previous value is maintained (step S9). Then, the dew condensation determination counter value is incremented by +1 (step S10).
Next, when the count value of the confirmation counter is less than the abnormality confirmation threshold value (step S7; No), the operation ends. On the other hand, when the control unit 10 determines that the count value of the determination counter is equal to or greater than the abnormality determination threshold value (step S7; Yes), the control unit 10 performs an abnormality determination process (step S8). Then, the operation ends.

  Returning to step S4, when it is determined that the measured values measured by the smoke detector 20, the heat detector 30, and the battery voltage monitoring circuit 60 do not exceed the fire threshold, the sensor abnormality threshold, or the battery exhaustion abnormality threshold (step S4). Next, the control unit 10 determines whether or not a fire or abnormality is being determined (step S11). When the control unit 10 determines that a fire or abnormality is being determined (step S11; Yes), the measurement value measured by the dew condensation detection circuit 70 is not at the dew condensation determination level (within a predetermined range in the dew condensation determination). ) Is determined (step S12).

When the measurement value by the dew condensation detection circuit 70 is not at the dew condensation determination level (within a predetermined range in the dew condensation determination) (step S12; No), the control unit 10 sets the value of the state determination counter 81 corresponding to fire or abnormality to -1. Is decreased by only (step S13). Then, it is determined whether or not the value of each state determination counter 81 = 0 (step S14). On the other hand, when the measurement value by the dew condensation detection circuit 70 is at the dew condensation determination level (out of the predetermined range in the dew condensation determination) (step S12; Yes), the control unit 10 decreases the value of each state counter 81 by -1. It is made to hold without making (step S16). Then, the value of the dew condensation determination counter 82 is increased by +1 (step S17), and the operation ends. Next, when it is determined that the value of the fire or abnormality state determination counter 81 is 0 (step S14; Yes), a fire or abnormality recovery process is performed (step S15), and the operation is terminated. On the other hand, when it is determined that the value of the fire or abnormality state determination counter 81 is not 0 (step S14; No), the operation ends without performing the fire or abnormality recovery process.
Returning to step S11, when the control unit 10 determines that a fire or abnormality has not been established (step S11; No), it is determined that all are normal and the operation ends.

As described above, when the measurement value measured by the dew condensation detection circuit 70 is out of the predetermined range in the dew condensation determination, the value of the state determination counter 81 is held regardless of whether there is a fire or an abnormality, and the state up to that point. The dew condensation determination counter 82 is incremented by +1 while maintaining the fixed counter 81 value. That is, when dew condensation is detected, the value of the state determination counter 81 is incremented by +1 when the fire threshold or abnormality threshold is exceeded, or the state determination counter value is decremented by -1 without exceeding the fire threshold or abnormality threshold. The value of the state determination counter 81 is prevented from changing.
When the measurement value measured by the dew condensation detection circuit 70 continues to be at the dew condensation determination level (out of the predetermined range in the dew condensation determination), if the dew condensation determination counter 82 is added, the accumulated time during which dew condensation has occurred. (Condensation detection operation cycle × number of determinations) can be calculated.
In this embodiment, the fire confirmation counter value A and the abnormality confirmation counter value B are different from each other. However, when A = B, for example, the state confirmation counter value at the time of fire is incremented by +3, and the state confirmation counter value at the time of abnormality is +1 may be added.
Further, the state determination counter 81 may be used for both fire and abnormality.
Further, a caution alarm may be output when the value (cumulative) of the dew condensation determination counter 82 stored in the EEP-ROM 4 every predetermined time becomes a predetermined value.

  In the above description, the case where the present invention is applied to a fire alarm device driven by a battery has been described as an example, but the method of supplying power is not limited to this. Furthermore, in the above description, the fire alarm device has been described as an example. However, the present invention can also be applied to an alarm device that detects abnormalities in other monitoring areas such as gas leakage.

1 battery, 2 constant voltage circuit, 3 inspection switch, 4 EEP-ROM, 10 control unit, 11 calculation unit, 12 ROM, 13 RAM, 14 timer unit, 15 A / D converter, 16 main clock oscillation unit, 17 sub Clock oscillation unit, 18 interface unit, 20 smoke detection unit, 21 infrared LED drive circuit, 22 photodiode current-voltage conversion circuit, 23 light receiving amplifier, 24 infrared LED, 30 heat detection unit, 31 fixed resistor, 32 thermistor, 40 Alarm sound control circuit, 41 Audio D / A converter, 42 Audio amplifier, 43 Speaker, 50 Indicator light circuit, 51 Confirmation light drive circuit, 52 Red LED, 60 Battery voltage monitoring circuit, 70 Condensation detection circuit, 71 Resistor , 72 switch, 81 status confirmation counter, 82 condensation determination counter, 100 fire alarm vessel.

Claims (4)

A state detector;
A state determination unit that determines a state based on an output signal of the state detection unit;
A control unit that outputs an alarm based on a determination result of the state determination unit;
A dew condensation detection unit that detects the occurrence of dew condensation and transmits a dew condensation detection signal to the control unit;
The control unit suspends the determination operation of the state determination unit when the dew condensation detection signal received from the dew condensation detection unit is out of a predetermined range. The dew condensation detection unit has a resistance unit in which a plurality of resistors having a high resistance value are connected in series, and the resistance unit is supplied with a stable voltage via a constant voltage circuit, and an intermediate potential thereof is detected as the dew condensation detection. The alarm device according to claim 1, wherein the alarm is transmitted to the control unit as a signal. The resistor unit includes a switch connected in series between the plurality of resistors,
The alarm device according to claim 2, wherein the control unit intermittently turns on the switch. The alarm device according to any one of claims 1 to 3, wherein the control unit stores the number of times the determination operation of the state determination unit is suspended or the determination content thereof in a storage unit.

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