JPH0620170A - Smoke sensing system - Google Patents

Abstract

PURPOSE:To prevent the blank period of a smoke sensing operation from being generated by detecting the non light emission of a light emitting lamp corresponding to a light emitting instruction and predicting the failure of the light emitting lamp beforehand. CONSTITUTION:From the time when a smoke sensor 1 is installed or a xenon lamp 10 is exchanged, the number of times when the xenon lamp 10 does not emit the light at the time to emit the light, that is, the number of the times of the non light emission is stored every month. That is, when a light emitting level by a light receiving element 20 does not arrive at a prescribed level at the time of the light emitting instruction from a control circuit 50, the number of the times of the non light emission is increased only by one. To put it concretely, a function (n) for indicating how many months are there before the month is set to '1' and the function An for indicating the number of the times of the non light emission in the (n)-th month is set to '0.' Thereafter, after every lapse of one month, the function (n) is increased by '1' and the function An is reset to '0.' Record is stored in an EEPROM 63 at every reset. Thus, the failure of the xenon lamp 10 can be recognized beforehand.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a light emitting lamp such as a xenon lamp and a light receiving element in a smoke chamber, emits light by the light emitting lamp, and responds to the output signal of the light receiving element receiving the light from the light emitting lamp. The present invention relates to a smoke sensing device that detects smoke concentration.

[0002]

2. Description of the Related Art A xenon lamp emits light, and in response to an output signal of a light receiving element that receives light from the xenon lamp,
In a conventional smoke detector such as a smoke detector that detects the concentration of smoke in a smoke chamber, when the xenon lamp emits light for a predetermined number of times or for a certain number of years, the emission efficiency decreases or does not stop, and the smoke detector As a result, normal operation cannot be performed.

[0003]

As described above, in order to detect the failure of the xenon lamp, the conventional method is as follows.
The light reception level from the xenon lamp is detected, and when the light reception level cannot be maintained above a predetermined level, it is determined that the xenon lamp has failed. Specifically, a time period of about 30 seconds or 1 minute is set in advance, and when the light receiving level higher than a predetermined level does not exist within this time, it is determined that the xenon lamp has failed. However, an alarm is sounded to inform that the xenon lamp is out of order.

However, with the above-mentioned conventional method, although it is possible to notify that the xenon lamp has already failed, it is not possible to predict the failure. Therefore, in the conventional example, after the xenon lamp actually fails, until the maintenance person knows the failure, the maintenance person knows that the xenon lamp has failed, and then the xenon lamp Since the smoke detector does not operate until the replacement is completed, there is a problem that a blank period occurs in the smoke detection operation. This problem also occurs in light emitting lamps other than the xenon lamp.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a smoke sensing device capable of preventing a blank period from occurring in a smoke sensing operation by allowing a failure of a light emitting lamp to be known in advance. Is.

[0006]

SUMMARY OF THE INVENTION The present invention has a smoke sensing device having a light emitting lamp and a light receiving element for receiving light from the light emitting lamp, and detecting smoke density according to an output signal of the light receiving element. In the above, the non-light emission of the light emitting lamp corresponding to the light emission command for causing the light emitting lamp to emit light is detected, and the number of non-light emission is stored.

[0007]

According to the present invention, in a smoke sensing device having a light emitting lamp and a light receiving element for receiving light from the light emitting lamp, the smoke sensing device detecting the smoke density according to the output signal of the light receiving element emits light from the light emitting lamp. No light emission of the light emitting lamp corresponding to the light emission command to be detected is detected, and the number of times of non-light emission is stored, so that the failure of the light emitting lamp can be known in advance by looking at the stored number of non-light emission. , It is possible to prevent a blank period from occurring in the smoke sensing operation.

[0008]

FIG. 1 is a block diagram showing an embodiment of the present invention.

In the smoke detector 1 of this embodiment, the smoke chamber 3
The xenon lamp 10 and the light receiving element 20 are provided in the interior of the lamp 0.
Separated by. And the xenon lamp 10
Is emitted, and the light is scattered by the smoke in the smoke chamber 30 and reaches the light receiving element 20, and depending on the amount of light received by the light receiving element 20, the smoke chamber 3
The control circuit 50 determines the smoke density within 0.

The xenon lamp 10 is supplied with a high voltage required for light emission from a high voltage generating circuit 12, and a trigger circuit 11
The light emission timing is controlled by the trigger signal supplied from. The trigger circuit 11 generates a trigger signal based on the control signal supplied from the control circuit 50.

The smoke chamber 30 is connected to a sampling pipe 31 for guiding the atmosphere in which the smoke detector 1 is provided to the smoke chamber 30, and a pipe 32 for guiding the air in the smoke chamber 30 to the outside of the smoke detector 1. A suction fan 33 is provided in the pipe 32.

The amplifier 40 amplifies the output signal of the light receiving element 20, its gain is controlled by the gain switching circuit 41, and the peak hold circuit 42 is a circuit for holding the peak of the output signal of the amplifier 40. , A / D
The conversion circuit 43 is a circuit that converts the analog signal output by the peak hold circuit 42 into a digital signal.

The control circuit 50 controls the entire smoke detector 1 and judges the current smoke density in the smoke chamber 30 based on the digital signal from the A / D conversion circuit 43. It consists of a computer.

The ROM 60 stores the program of the flowchart shown in FIG.
Is a ROM that stores the number of times the xenon lamp 10 does not emit light (the number of times of no light emission) when it should emit light, and stores the number of times of no light emission for each month. RAM64 is
It is a working memory.

The D / A conversion circuit 71 is a signal transmission circuit 7
2. To send a signal to the receiver 2 via the connector C,
It is a circuit that converts a digital signal output by the control circuit 50 into an analog signal.

Light receiving element 20, control circuit 50 and ROM 60
Is an example of non-emission detecting means for detecting non-emission of the light-emitting lamp corresponding to the light-emission command by monitoring the light-emission command for causing the light-emission lamp to emit light and the light-emission of the light-emission lamp. It should be noted that the non-light-emission detecting means determines that the light-emitting lamp is non-light-emissive unless the light-receiving element 20 detects light-emission when the light-emission command is issued. Also, EEP
The ROM 63 is an example of a storage unit that stores the number of times of no light emission for each predetermined period. The EEPROM 63 is also an example of electrically rewritable nonvolatile storage means.

Next, the operation of the above embodiment will be described.

FIG. 2 is a flow chart showing the operation of the above embodiment.

First, in this embodiment, the xenon lamp 1 is used.
The number of times that 0 does not emit light when it should emit light, that is, the number of times of no light emission is stored for each month. Since the number of non-light emission in the first month is counted from when the smoke sensor 1 is installed or when the xenon lamp 10 is replaced, the function n indicating the number of months is set to "1". Together with a function An indicating the number of times of no light emission in the nth month
Is set to "0" (S1). After that, every time one month elapses (S2), the function n is incremented by 1, and the function An of the number of no light emission in the new month is set to "0" (S3).

Then, when a light emission command is issued from the control circuit 50 (S4) and the level of light received by the light receiving element 20 does not reach the predetermined level (S5), the number of non-light emission is increased by 1 ( S6). That is, the function An of the number of non-emissions in that month is increased by 1, and this number is increased by EEPR.
It is stored in the corresponding part of the OM 63. These operations (S2-
S6) is executed each time a light emission command is generated.

Thereafter, the smoke density detection operation is performed (S2).
0). That is, the signal output from the light receiving element 20 is sent to the amplifier 4
0 is amplified, the peak value is held by the peak hold circuit 42, the held value is converted into a digital signal by the A / D conversion circuit 43, and the control circuit 50 changes the smoke density based on the digital signal. Determine. Then, the D / A conversion circuit 71 converts it into an analog signal, and a signal is sent to the receiver 2 via the signal sending circuit 72 and the connector C, and the receiver 2 displays the smoke density based on this signal. .

FIG. 3 shows the EEPRO in the above embodiment.
It shows an example of storing the number of times of no light emission stored in M63. In this example, from the installation of the smoke sensor 1 to the first to sixth months, no non-light emission occurs once, and at the seventh and eighth months, respectively, once, respectively, once, respectively, 9, 10, 11, 12, 1
It has occurred 3, 2, 3, 5, 10 times each in the 3rd month. By looking at these stored contents, it is possible to determine whether or not it is time to replace the xenon lamp 10 installed in the smoke detector. That is, when the xenon lamp 10 breaks down, the number of times of non-light emission usually gradually increases, and after the number of times increases to some extent, the xenon lamp 10 breaks down. Can make predictions.

In the above embodiment, the case where the xenon lamp is used has been described, but any light emitting lamp other than the xenon lamp is the same as the above xenon lamp as long as the light emitting lamp has an unstable failure mode.

In the above embodiment, if the light receiving element 20 does not detect the light emission when the light emission command is issued, it is determined that the light emitting lamp does not emit light. However, instead of this, another non-light emission detecting means. May be provided. That is, a light receiving element other than the light receiving element 20 or a heat sensitive element for detecting heat of a light emitting lamp is provided, and when a light emitting command is generated, the light receiving element other than the light receiving element 20 does not detect light emission, or the heat sensitive element emits light. If is not detected, it may be determined that the light emitting lamp does not emit light. Alternatively, the change in the output voltage or the output current of the high-voltage generating circuit 12 may be checked, and if the change is smaller than usual, it may be determined that the light emitting lamp does not emit light.

In the above-described embodiment, the control circuit 50 determines that no light is emitted by using the light emission command generated by the control circuit 50 itself. However, in addition to the light emission command generated by the control circuit 50 itself, a light emitting lamp is used. No light emission may be determined by using the trigger signal of 1 or the control signal of the trigger circuit 11 as the light emission command. Further, in the above-mentioned embodiment, the EEPROM 63 stores the number of non-emissions for each month, but the non-emission is given for each predetermined period other than the month, such as every week, every 10 days, every 100 days. The number of times may be stored. Further, instead of the EEPROM 63, a RAM with a backup battery or a simple R
You may make it use AM.

In the above embodiment, the analog signal indicating the smoke density is transmitted to the receiver 2, but a digital signal may be transmitted instead of the analog signal.

In the above embodiment, the case where the smoke detector is a smoke detector has been described. However, a storage means such as an EEPROM for storing the number of times of non-light emission is provided in the receiver 2 or a repeater (not shown). May be. In this case, when the smoke detector detects no light emission, a signal indicating that no light emission has occurred is sent from the smoke detector to the receiver 2 or the repeater, and the receiver 2 or the repeater detects each sensor. The result is added and stored in the storage means corresponding to, for example, on a monthly basis.

[0028]

According to the present invention, in the smoke detector in which the light receiving element receives the light from the light emitting lamp and the smoke concentration is detected according to the output signal of the light receiving element, failure of the light emitting lamp is detected in advance. Therefore, it is possible to prevent the blank period from occurring in the smoke sensing operation.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of the above embodiment.

FIG. 3 shows an example of storing the number of non-light emission times stored in an EEPROM 63 in the above embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Smoke detector, 2 ... Receiver, 10 ... Xenon lamp, 11 ... Trigger circuit, 20 ... Light receiving element, 30 ... Smoke chamber, 40 ... Amplification circuit, 41 ... Gain switching circuit, 50 ... Control circuit, 60 ... ROM , 63 ... EEPROM for storing the number of times of non-emission.

Claims (5)

[Claims] 1. A smoke sensing device having a light emitting lamp and a light receiving element for receiving light from the light emitting lamp, wherein the smoke sensing device detects the density of smoke according to an output signal of the light receiving element. No-light-emission detecting means for detecting non-light-emission of the light-emitting lamp corresponding to the light-emission instruction by monitoring an instruction and light-emission of the light-emission lamp; storage means for storing the number of non-light-emissions every predetermined period. A smoke sensing device having; 2. The non-light-emission detection means according to claim 1, wherein the light-emitting lamp does not emit light unless the light-receiving element detects light-emission corresponding to the light-emission command when the light-emission command is generated. A smoke sensing device, which is characterized by being judged as. 3. The non-light-emission detecting means according to claim 1, wherein when a light-emission command is generated, a heat-sensitive element other than the light-receiving element or a heat-sensitive element for detecting heat of the light-emitting lamp is instructed to emit the light-emission command. A smoke sensing device, characterized in that if the corresponding light emission is not detected, it is determined that the light emitting lamp does not emit light. 4. The light emitting command for causing the light emitting lamp to emit light according to claim 1, wherein the light emitting command is for a light emitting command in a control circuit for controlling light emission of the light emitting lamp, a control signal for a trigger circuit, or the like. A smoke sensing device, which is a trigger signal of a light emitting lamp. 5. The smoke sensing device according to claim 1, wherein the storage unit is an electrically rewritable nonvolatile storage unit.