JP4974560B2 - Fire alarm - Google Patents

Description

  The present invention relates to a fire alarm device driven by a battery.

  Conventionally, this type of fire alarm device is provided with an alarm sounding circuit that sounds an alarm sound when a fire is detected or when an inspection abnormality occurs (when a battery voltage drops or a sensor is abnormal) (see Patent Document). . In general, an alarm sounding circuit is composed of an amplifier circuit that amplifies an alarm sound and an acoustic unit such as a buzzer or a speaker that outputs the amplified alarm sound. For example, a fire alarm is defined by the standards of the Fire Service Act. As shown, the output is performed with a sound pressure of 70 dB or more.

JP 2006-039829 A

  However, when the sound pressure of the alarm sound is increased, the current consumption during the alarm sound is increased in proportion thereto. In general, as the battery capacity is consumed, the internal resistance increases and the maximum discharge current that can be taken out of the battery decreases. In order for the alarm device to operate normally, the maximum current consumption of the alarm device at the time of alarm or the like needs to be smaller than the maximum discharge current of the battery. Therefore, the larger the maximum current consumption of the alarm device, the more the system cannot operate before the battery capacity is used up, and the useful life of the battery is shortened. In order to further extend the battery life (use up the capacity of the battery), it is necessary to reduce the maximum current consumption of the alarm device. However, in order to increase the sound pressure of the alarm sound, it is necessary to increase the current consumption when the alarm sounds.

  The present invention has been made in view of the above points, and provides a fire alarm capable of substantially extending the battery life by performing an alarm sound by limiting the current when the voltage of the battery drops. With the goal.

A fire alarm device according to the present invention includes a battery that supplies power to each internal circuit, a battery voltage detection circuit that detects a battery voltage, a fire detection circuit that detects and outputs an environmental change based on a fire phenomenon, and a battery voltage detection a control circuit for the fire detection signal of the battery voltage detection signal and the fire detection circuit of the circuit is input, a warning alarm sound ringing circuit, the fire alarm device having a warning sound ringing circuit, the variable can amplify the amplifier gain And an acoustic unit that outputs an alarm sound amplified by the amplification unit, and the control circuit determines whether or not an alarm is necessary based on a fire detection signal from the fire detection circuit, and determines that it is necessary In this case, the battery voltage level is determined based on the battery voltage detection signal from the battery voltage detection circuit, and when the battery voltage level is lower than a predetermined level , the sound pressure is about 80 dB or more during normal ringing. Low, 70 As an alarm sound from the sound unit in a sound pressure of approximately B, and to output the amplifier gain control signal for controlling the lower gain than the normal ringing to the amplifier.

A fire alarm device according to the present invention includes a battery that supplies power to each internal circuit, a battery voltage detection circuit that detects a battery voltage, a fire detection circuit that detects and outputs an environmental change based on a fire phenomenon, and a battery voltage detection a control circuit for the fire detection signal of the battery voltage detection signal and the fire detection circuit of the circuit is input, a warning alarm sound ringing circuit, the fire alarm device having a warning sound ringing circuit, the variable can amplify the amplifier gain And an acoustic unit that outputs an alarm sound amplified by the amplification unit, and the control circuit determines whether or not an alarm is necessary based on a fire detection signal from the fire detection circuit, and determines that it is necessary In this case, the battery voltage level is determined based on the battery voltage detection signal from the battery voltage detection circuit, and when the battery voltage level is lower than a predetermined level , the sound pressure is about 80 dB or more during normal ringing. Low, 70 As an alarm sound from the sound unit in a sound pressure of approximately B, since the amplifier gain control signal for controlling the lower gain than the normal ringing to output to the amplifier, can control the amplifier gain with a simple structure . Therefore, when the alarm is required and the battery voltage level is lower than the predetermined level, the current is limited by lowering the amplifier gain, and the alarm is generated. Thereby, battery life can be extended.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing the configuration of the fire alarm. In FIG. 1, a solid line indicates wiring, and a dotted line indicates a signal flow.
In FIG. 1, reference numeral 1 denotes a power supply for each internal circuit to be described later, for example, a battery having a rated voltage of DC 3.0V, and 2 a constant voltage circuit for supplying a constant voltage power supply having a constant voltage (for example, 2.3 V) from the battery voltage. 3 is a control circuit composed of a one-chip microcomputer that controls each internal circuit in the fire alarm, 4 is a fire detection circuit that detects and outputs environmental changes such as smoke and heat based on the fire phenomenon, A battery voltage detection circuit for detecting the battery voltage; 6 a power supply voltage abnormality monitoring circuit for monitoring the power supply voltage of the constant voltage circuit 2; 7 an inspection / audio stop circuit for performing an inspection and an audio stop by an inspection switch (not shown); 8 is an audio sounding circuit as an example of an alarm sounding circuit that performs sounding by an audio amplifier / speaker, and 9 is a plurality of light emitting diodes (here, for example, a red light emitting diode and a green light emitting diode). A fire trouble display circuit for performing status display alarm that.

  The fire detection circuit 4 includes a booster / light emitting circuit 4a that emits light from an infrared light emitting diode for fire detection, and a light receiving amplifier circuit 4b that receives and amplifies scattered light generated by the infrared light emitting diode of the booster / light emitting circuit 4a. Have.

  The control circuit 3 periodically takes in signals from each internal circuit and performs processing according to the signals. Specifically, a signal (fire detection signal) is received from the light receiving amplification circuit 4b of the fire detection circuit 4, and it is determined whether or not an alarm is necessary based on the fire detection signal. The battery voltage level is determined based on the battery voltage detection signal from the battery voltage detection circuit 5. Then, the sound ringing circuit 8 is controlled to output alarm ringing sound data at an output level according to the determination result. Specifically, when the battery voltage level is lower than a predetermined level, an alarm is sounded with a lower sound pressure than during normal sounding when the battery voltage level is not lower than the predetermined level. The alarm sounding circuit 8 is controlled. The voice data is obtained from the control circuit 3.

FIG. 2 is a circuit diagram showing an example of the configuration of the sound ringing circuit 8 of FIG.
The sound ringing circuit 8 includes an amplifier (amplifying unit 11) that inputs and amplifies the sound data from the control circuit 3, and a speaker (sound unit 12) that outputs the amplified sound. The amplifying unit 11 and the control circuit 3 are connected so that the current value supplied to the amplifying unit 11 can be controlled, and the sound pressure level of the alarm ringing is controlled by controlling the current value. Yes.

Hereinafter, the connection between the amplifier 11 and the control circuit 3 will be described.
Resistors 13A (small resistance value) and 14A (large resistance value) having different resistance values are connected in parallel to the constant voltage circuit 2 side of the amplifying unit 11, and one end of each transistor 13B and 14B is connected to each resistor 13A and 14A. Are connected in series, and the other ends of the transistors 13B and 14B are connected to the constant voltage circuit 2. The transistors 13B and 14B and the control circuit 3 are connected to each other by audio amplification control lines 13C and 14C. Each of the transistors 13B and 14B is turned on when a LOW level signal is input from the control circuit 3, and the HI level signal is input while the alarm is not sounded, and is in an OFF state.
With this connection, currents I having different current values are supplied to the amplifying unit 11 in accordance with signals output from the control circuit 3 to the audio amplification control line 13C and the audio amplification control line 14C.
The control circuit 3 is connected to the amplifying unit 11 via a data output line 15 that outputs audio data.

FIG. 3 is a flowchart showing the operation of the control circuit 3 when sounding.
The control circuit 3 determines whether or not an alarm is necessary based on the fire detection signal from the fire detection circuit 4. If it is determined that the alarm is necessary, the control circuit 3 determines the battery voltage based on the battery voltage detection signal from the battery voltage detection circuit 5. Is determined (S1). If it is determined that the battery voltage level is equal to or higher than a predetermined level (for example, 2.5 V), it is determined that the battery normally rings and the signal output to the audio amplification control line 13C is changed from HI to LOW. Thereby, the transistor 13B is turned on, and the constant voltage circuit 2 and the amplifying unit 11 are connected via the resistor 13A. Further, the control circuit 3 outputs necessary audio data to the amplifying unit 11 via the data output line 15. As a result, a current for normal ringing flows through the amplifying unit 11, and normal ringing is performed with a sound pressure of, for example, about 80 dB.

  On the other hand, if it is determined in step S1 that the battery voltage level is lower than the predetermined level, it is determined that the current limit ringing is performed, and the signal output to the audio amplification control line 14C is changed from HI to LOW. Thereby, the transistor 14B is turned on, and the constant voltage circuit 2 and the amplifying unit 11 are connected via the resistor 14A. Further, the control circuit 3 outputs necessary audio data to the amplifying unit 11 via the data output line 15. Since the resistor 14A is larger than the resistor 13A, the current flowing through the amplifying unit 11 is smaller than that during normal ringing. Therefore, the current-limited ringing is performed, for example, the ringing is performed with a sound pressure of about 70 dB.

  Thus, according to the first embodiment, when the battery voltage is lowered when the alarm is sounded, the current consumption for the alarm sound is suppressed as compared with the normal sounding time, so that the battery life is extended. Is possible. On the other hand, at the normal time, it is possible to relax the current limitation at the time of sounding the alarm and obtain a higher sound pressure.

  Further, the sound ringing circuit 8 is connected to the constant voltage circuit 2 side of the amplifying unit 11 in parallel, the resistors 13A and 14A having different resistance values, and one end connected in series to each of the resistors 13A and 14A and the other end having a constant voltage. Since each of the transistors 13B and 14B is connected to the circuit 2 and the current value supplied to the amplifying unit 11 is controlled by controlling on / off of each of the transistors 13B and 14B from the control circuit 3, the configuration is simple. The current value supplied to the amplifier 11 can be controlled with a simple configuration.

  In the first embodiment, the sound ringing circuit 8 that outputs the sound data amplified by the amplification unit 11 from the sound unit 12 is shown as the alarm sound ringing circuit. However, the sound ringing circuit 8 may be sound data such as a buzzer sound. As shown in FIG. 4, an acoustic sounding circuit 81 that sounds the buzzer 31 may be used. In this configuration, when an alarm is required, the HI signal and the LOW signal are alternately output from the control circuit 3 to the sound output control line 32 in accordance with the oscillation frequency of the buzzer 31 (for example, about 3 kHz) 33 repeats ON / OFF alternately. As a result, when the battery voltage is normal, a large current flows through the buzzer 31 in the same manner as described above, and when the battery voltage is low, a small current is generated compared to the normal time when the battery voltage is low. It will sound smaller than normal.

Embodiment 2. FIG.
The fire alarm device of the second embodiment is provided with a voice ringing circuit 82 instead of the voice ringing circuit 8 shown in the first embodiment.

FIG. 5 is a diagram illustrating a connection example between the sound ringing circuit 82 and the control circuit 3 provided in the fire alarm device according to the second embodiment. In FIG. 5, the same parts as those in FIG.
In the sound ringing circuit 82 of the third embodiment, the amplifying unit 11 is connected to the constant voltage circuit 2 via the transistor 21, and the transistor 21 is connected to the control circuit 3 via the sound output control line 22. The amplifying unit 11 is connected to the control circuit 3 via the amplifier gain control line 23 and can change the amplifier gain by an amplifier gain control signal from the control circuit 3. Based on the amplifier gain control signal, the signal is amplified and output from the acoustic unit 12.

  In the fire alarm device according to the second embodiment having the sound ringing circuit 82 configured as described above, when the control circuit 3 determines that the alarm ringing is necessary, the control circuit 3 outputs a LOW signal to the sound output control line 22 and turns on the transistor 21. Turns on and supplies power to the amplifier 11. Then, when it is determined that the sound is normal, the sound data and an amplifier gain control signal for controlling the sound data to be output at a high output are output to the amplifying unit 11 via the amplifier gain control line 23. The amplifying unit 11 amplifies the audio data according to the amplifier gain control signal from the control circuit 3 and outputs the amplified audio data to the acoustic unit 12. Thereby, for example, ringing is performed with a sound pressure of about 80 dB. On the other hand, if it is determined that the current limit ringing is performed, the control circuit 3 controls the audio data and an amplifier gain control signal (a gain lower than that during the normal ringing) for controlling the audio data to be output at a lower output than during the normal ringing. (Amplifier gain control signal to be controlled) is output to the amplifying unit 11 via the amplifier gain control line 23. The amplifying unit 11 amplifies the audio data according to the amplifier gain control signal from the control circuit 3 and outputs the amplified audio data to the acoustic unit 12. Thereby, for example, ringing is performed with a sound pressure of about 70 dB.

  As described above, according to the second embodiment, the amplifying unit 11 whose amplifier gain can be varied by the amplifier gain control signal from the control circuit 3 is used, and the amplifying unit 11 and the control circuit 3 are connected by the amplifier gain control line. Therefore, the amplifier gain can be controlled with a simple configuration. Therefore, when the alarm is required and the battery voltage level is lower than the predetermined level, the current is limited by lowering the amplifier gain, and the alarm is generated. As a result, the battery life can be extended.

It is a block diagram which shows the structure of a fire alarm. It is a circuit diagram which shows an example of a structure of the sound ringing circuit of FIG. It is a flowchart which shows operation | movement of the control circuit at the time of performing sound ringing. It is a figure which shows an acoustic ringing circuit. It is a figure which shows the example of a connection of the sound ringing circuit provided in the fire alarm device of Embodiment 2, and a control circuit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Battery 2 Constant voltage circuit 3 Control circuit 4 Fire detection circuit 4a Boosting / light emission circuit 4b Light reception amplification circuit 5 Battery voltage detection circuit 6 Power supply voltage abnormality monitoring circuit 7 Inspection / sound pressure stop circuit 8 Sound ringing circuit 9 Fire / abnormality display circuit DESCRIPTION OF SYMBOLS 11 Amplification part 12 Acoustic part 13A Resistance 13B Transistor 13C Audio | voice amplification control line (acoustic amplification control line)
14A Resistance 14B Transistor 14C Audio amplification control line (acoustic amplification control line)
15 Data output line 21 Transistor 22 Audio output control line 23 Amplifier gain control line 32 Acoustic output control line 33 Transistor 81 Acoustic ringing circuit 82 Audio ringing circuit

Claims (1)

A battery that supplies power to each internal circuit, a battery voltage detection circuit that detects a battery voltage, a fire detection circuit that detects and outputs an environmental change based on a fire phenomenon, a battery voltage detection signal of the battery voltage detection circuit, a control circuit for the fire detection signal of the fire detector is input, a warning alarm sound ringing circuit, the fire alarm device having a
The alarm sounding circuit has an amplification unit that can vary an amplifier gain and an acoustic unit that outputs an alarm sound amplified by the amplification unit,
The control circuit determines whether or not an alarm sound is necessary based on a fire detection signal from the fire detection circuit, and if determined to be necessary, a battery based on a battery voltage detection signal from the battery voltage detection circuit. The voltage level is determined, and when the battery voltage level is lower than a predetermined level , an alarm is sounded from the acoustic unit at a sound pressure of about 70 dB, which is lower than a sound pressure of about 80 dB during normal sounding. And an amplifier gain control signal for controlling the gain to be lower than that during normal ringing .

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