JPS6077296A - Alarm - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an alarm device that detects abnormalities such as fire and gas leaks and issues an alarm.

[Technical background of the invention and its problems] Figure 1 is a circuit diagram showing the configuration of a conventional alarm device called a fire alarm.
Mainly, a sensor 1 made of bimetal or the like, and a fire detection circuit 1 as an alarm circuit that generates an alarm in response to this sensor.
00.

Of these, the fire detection circuit 100 includes a master alarm, an alarm lamp 2
, a speaker 3, an oscillation circuit 10 using an integrated circuit, transistors 2 to 5 for operating these, and the like.

Here, when sensor l turns on, transistor 4 also becomes conductive (hereinafter, conduction of the transistor is referred to as on, and disconnection of the transistor is referred to as off)
Then, the alarm lamp 2 connected in series to this transistor 4 lights up.

On the other hand, when transistor 40 is turned on, transistor 5 is turned off and power supply voltage is supplied to oscillation circuit 10, and an alternating current corresponding to the oscillation signal flows into the base of transistor 6, turning this transistor on and off. This causes the speaker 3 connected in series to the transistor 6 to generate sound waves of a specific frequency.

Thus, when a fire breaks out, the alarm lamp 2 and speaker 6 can notify, for example, the occupants of the building on fire or the manager.

In such a conventional fire alarm, when the sensor 1 is turned on, it is determined whether the alarm lamp 3 and the speaker 6 operate reliably. It did not have a so-called self-diagnosis function. Therefore, even if just one component is destroyed, the alarm circuit may become inoperable, which could lead to a serious problem without being noticed.

This situation is not limited to the above-mentioned fire alarm system, but also applies to alarm systems that detect gas leaks or intrusion by a single person.

[Purpose of the invention]

The present invention has been made in order to eliminate the drawbacks of the conventional systems described above, and an object of the present invention is to provide an alarm device that can quickly notify a failure in which the alarm circuit cannot perform its normal function.

[Summary of the invention]

To achieve this objective, the present invention provides a valuable device.

A sensor that detects an abnormality such as a fire or a gas leak, an alarm circuit that monitors the state of this sensor and causes an alarm to respond to the sensor, and a signal of the same type when the sensor detects an abnormality is sent to the alarm an oscillator circuit that applies voltage to the input end of the alarm circuit for a short period of time without being impressed;
failure detection means for determining whether or not the same type of signal is given to the alarm when the alarm is activated by the signal of the oscillation circuit, and generating a fault alarm when this signal is not given to the alarm; It is characterized by the following:

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to one drawing.

FIG. 2 shows an example of the configuration of an alarm device according to the present invention, in which the same reference numerals as in the first section indicate the same elements. Then, at the input end of the alarm device 100 that inputs the ON operation signal of the sensor 1, that is, at the base of the transistor 40,
A pulse oscillator 20, which serves as an oscillation circuit that repeatedly gives a pulse signal with an H level time of about several milliseconds, and the output end of the fire detection circuit 100, that is, the collector voltage of the transistor 6, are all detected, and the voltage opposite to that of the transistor 6 is detected. A monostable multivibrator 30 receives the voltage between the emitter and collector of the operating transistor 7, and receives the output voltage of this monostable multivibrator 30 via a transistor 8, and this transistor 8 remains off even after a predetermined time has passed. A timer circuit 40 that sounds a buzzer when
This is a new addition.

The operation of the alarm device configured as described above will be explained below with reference to FIGS. 3 and 4.

First, in the fire detection circuit 100, as explained using FIG. .

Next, when sensor 1 is in the off state, pulse oscillator 2
0 is the same type as when this sensor is turned on, and the time width is shorter than the impression time of the speaker 3. A pulse signal shown in FIG.
Apply to the point. As a result, the transistor 6 is turned on for a time corresponding to this pulse signal, and the collector of the transistor 7 disposed in the subsequent stage, that is, the third
As shown in Figure (b), a pulse signal having approximately the same waveform as the input pulse appears.

Subsequently, the pulse signal appearing at the collector of the transistor 7 is applied to the monostable multivibrator 30, and from its output terminal, that is, point D, a pulse signal with a duty ratio of approximately 1/2 is output as shown in FIG. 3(C). is output.

On the other hand, the timer circuit 40 is composed of a charging circuit in which a resistor and a capacitor C1 are connected in series, a voltage dividing circuit in which two resistors are connected in series, an operational amplifier, a buzzer, etc. is connected to the non-inverting input terminal (G) of the operational amplifier, and the junction point E between the resistors of the voltage dividing circuit is connected to the inverting input terminal (←) of the operational amplifier. Further, the output terminal of the operational amplifier is connected to the base of a transistor connected in series with the buzzer.

Therefore, the potential at point E is kept approximately constant, and the potential at point D changes depending on the state of charge of capacitor C1. When the voltage at point D with respect to the ground point is VD, and the voltage at point E is VE,
A buzzer D is arranged to sound if VD≧vE.

Here, the output cover of the monostable multivibrator 30 is 16
When a signal is applied to the base of the transistor 80, the transistor 8 is turned on and off at approximately equal intervals, so that the capacitor c1 is repeatedly charged and discharged, and the voltage VD fluctuates within a certain range.

Note that since the voltage VE is set higher than the variation range of this VD, the buzzer of the timer circuit 40 does not sound as long as the pulse signal shown in FIG. 3(c) is applied to the transistor 8.

On the other hand, any of the alarm circuits 100 Ill! ] If the component is destroyed, even if a pulse signal is applied to point A, a corresponding signal will not be generated at point B, so the timer is activated.

The transistor 8 provided at the front stage of the circuit 40 continues to be in the off state. As a result, the capacitor C1 continues to be charged, and when the voltage V at point D exceeds the voltage VE at point E, the buzzer sounds to notify that the fire detection circuit 100 has failed.

FIG. 4 is a diagram showing this relationship. When the fire detection circuit 100 is normal, the voltage VD at point D fluctuates in a range lower than the voltage at point E. When the fire detection circuit 100 is abnormal,
When the voltage VD at the point rises rapidly and becomes VD≧VE, a failure will be notified.

In addition, in the above embodiment, a bimetal is used as the sensor,
The state of this sensor is monitored by a fire detection circuit, and the fire detection circuit itself is equipped with an alarm such as a speaker. However, the sensor for detecting fire may also be one that detects smoke. Even if an alarm device such as a speaker is configured independently from the fire detection circuit, failure detection similar to that described above is possible.

Further, in the above embodiment, the pulse voltage generated at the collector of the transistor 7 is passed through the monostable multivibrator 30 to the base of the transistor 80, but if the capacitor C□ can be reliably discharged, If the pulse width can be widened, the same effect as described above can be achieved even if the monostable multivibrator is removed.

Furthermore, the present invention is not limited to fire detection, but can also be applied to continuous alarm systems that detect gas leaks, human intrusion, elevator failures, and the like.

〔Effect of the invention〕

As is clear from the above explanation, according to the alarm device of the present invention, it is possible to promptly notify a failure in which the alarm circuit cannot perform its normal function, thereby preventing serious accidents that are likely to occur when the failure of the alarm circuit is not noticed. The excellent effect of preventing this has been achieved.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing the configuration of a conventional alarm device. FIG. 2 is a circuit diagram showing the configuration of an embodiment of the alarm device according to the present invention, and FIGS. 3 and 4 are time charts for explaining the operation of the embodiment. DESCRIPTION OF SYMBOLS 1... Sensor, 2... Alarm lamp, 3... Speaker as alarm, 20... Pulse oscillator as oscillation circuit, 30... Monostable multivibrator, 40
...Timer circuit, 100...Fire detection circuit as an alarm circuit. Applicant's agent Kiyoshi Inomata b3 Tsuratara 4 Figure □Oshizukutoki-+--Kaioeji- Procedural amendment (method) % formula % 1. Indication of the case 1986 Patent Application No. 186278 2. Title of the invention Information device 3, relationship with the amendment person case Patent applicant (307) Tokyo Shibaura-ku Ki Co., Ltd. January 11, 1982

Claims (1)

[Claims] 1. A sensor that detects abnormalities such as fire and gas leaks, and an alarm circuit that monitors the state of the sensor and causes an alarm to respond to the sensor. an oscillation circuit that applies a signal of the same type when the sensor detects an abnormality to the input end of the alarm circuit for a short period of time when the alarm is not affected; and a signal from the oscillation circuit that operates the alarm. 1. An alarm device comprising: failure detection means for determining whether or not a signal of the same type as the above is applied to the alarm, and generating a failure alarm when the signal is not applied to the alarm. 2. A contact type sensor is used as the sensor, and the oscillation circuit is a pulse oscillator that continuously generates a pulse signal at a predetermined period with a time width that does not affect the alarm. - The failure detection means C monostable multivibrator,
2. The alarm device according to claim 1, further comprising a timer circuit which generates a failure alarm signal when the output signal level of the monostable multivibrator does not change after a predetermined period of time.