JP3254565B2 - Thermoelectric fire detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoelectric fire detector.

[0002]

2. Description of the Related Art A conventional thermo-electric fire detector monitors a fire based on smoke and heat generated by the occurrence of a fire. When smoke is generated due to a fire, light emitted from the smoke detecting light emitting element of the light emitting section is scattered by the smoke and enters the smoke detecting light receiving element of the light receiving section. The scattered light entering the light receiving element is amplified through an amplifier circuit, and then output to a fire discrimination unit, and a fire discrimination is performed based on the output value. When it is determined that a fire has occurred, the determination unit transmits a fire signal to the fire signal transmission unit via the storage circuit. Further, when heat is generated by a fire, the thermal element of the heat detecting section outputs a detection output, and when the detection output reaches a predetermined level, the heat / fire determining section outputs a fire signal to a fire signal transmitting section. Then,
The sending unit sends this fire signal to a fire receiver or the like to notify the fire.

In a conventional thermoelectric fire detector, the sensitivity of the detector is adjusted by sensitivity adjustment means, and the operation of a fire discriminator and the like is stabilized by a constant voltage circuit. Also,
The pulse output of the oscillating circuit is supplied to the operation indicator lamp, and the indicator lamp is turned on and off to confirm whether or not the sensor is operating normally.

[0004]

The conventional thermoelectric fire detector has the following problems. (1) In the sensitivity adjustment of the conventional example, a reflector that generates scattered light equivalent to scattered light generated when, for example, 10% / m of smoke enters, is placed in a smoke detection dark box of a thermoelectric fire detector. The reference resistor of the comparator is selected so that the fire detection circuit, for example, the comparator operates based on the detection output at that time.

However, in such a method, since the detection output differs depending on the variation of the circuit constant of the electric circuit in each thermoelectric fire detector, the sensitivity adjustment, that is, the selection of the reference resistance is troublesome. Also, since the detection output is different for each thermoelectric fire detector, the sensitivity of the sensor is different, so if you want to know how the sensitivity of the sensor has changed from the initial state, the initial detection of each sensor You have to know the output, which is troublesome.

(2) The conventional storage circuit is composed of a plurality of D-type flip-flops. However, this storage circuit may operate when the power is turned on, for example, when a fire recovery operation is performed, and the fire signal transmitting unit may erroneously transmit a fire signal.

(3) The conventional constant voltage circuit comprises a transistor, a Zener diode connected to the base of the transistor, and a resistor connected between the collector and base of the transistor. .

However, in this constant voltage circuit, if there is a large difference between the power supply voltages supplied to the sensors for each fire receiver, the current consumed in the constant voltage circuit of the sensor by the connected fire receivers. to differ greatly. For example, when the power supply voltage is high, the current flowing through the Zener diode ZD of the voltage stop circuit increases, and when the power supply voltage is low, the current flowing through the Zener diode ZD of the constant voltage circuit decreases.

Therefore, in the case of a fire signal having a high power supply voltage to be supplied to the sensor, the number of connectable sensors is smaller than that of a fire receiver having a low power supply voltage. Therefore, there is a disadvantage that it is greatly restricted.
Further, the power supply voltage of the fire receiver may be unstable and fluctuate. In this case, if the smoke detector is changed to a fire detector having a semiconductor circuit, the required number of fire detectors cannot be connected.

(4) The oscillation circuit of the conventional operation indicator lamp is
It is provided separately and independently from a pulse oscillation circuit for supplying a pulse output for light emission to the smoke detection light emitting element of the light emitting section. Therefore, even if the smoke detection pulse oscillation circuit breaks down and the light emitting element does not emit light, that is, even if fire monitoring cannot be performed, the indicator lamp blinks and lights if the oscillation circuit of the indicator lamp is normal. , Indicating that the sensor is normal.

SUMMARY OF THE INVENTION In view of the above circumstances, it is an object of the present invention to easily and accurately adjust a sensitivity and to prevent a malfunction of a storage circuit. Another object is to keep the current consumption of the constant voltage circuit constant and to ensure that the operation indicator goes off when the fire detector fails and smoke detection is no longer possible.

According to the present invention, there is provided a light emitting unit including a light emitting element for smoke detection, an oscillation circuit for supplying a pulse output to the light emitting element, and a light emitting unit which does not directly receive light emitted from the light emitting element for smoke detection. A light receiving section including a smoke detecting light receiving element for receiving the scattered light of the emitted light; an amplifier circuit for amplifying and outputting the light receiving output of the light receiving element; A photoelectric fire detection unit including a smoke fire detection unit that outputs a smoke fire output when the above is reached; a heat detection element for generating an output according to the physical quantity of the detected heat; and the heat detection element A heat fire discriminator that outputs a heat fire output when the detected output of the heat sensor reaches a predetermined level, wherein the pulse output is divided and supplied from the oscillation circuit as a monitoring power supply. A detector and a smoke fire detector of the smoke fire detector And a fire signal transmitting unit for transmitting a fire signal by operating in accordance with one of the heat fire outputs of the heat fire discriminating unit, and a thermo-electric fire detector. It is to achieve the purpose.

[0013]

When the oscillation circuit of the light emitting section outputs a pulse to the smoke detecting light emitting element, the light emitting element emits a pulse light toward the smoke detecting light receiving element of the light receiving section. Further, the pulse output is supplied to an operation indicator after the pulse width is expanded through a pulse width expansion circuit. This causes the operation indicator lamp to blink. At the same time, power is supplied from the oscillation circuit of the light emitting section to the heat detecting section, and the heat detecting section detects heat.

When smoke enters the dark box of the detector due to the occurrence of a fire, scattered light enters the smoke detecting light-receiving element of the light-receiving section, and the scattered light becomes a light-receiving output and enters the first-stage amplifier circuit. Therefore, after being amplified, it is further amplified by the second stage amplifier circuit,
It becomes the received light amplification output. When this amplified output is supplied to the smoke fire discrimination section, the transistor for fire discrimination turns on and outputs it to the storage circuit.

In this storage circuit, it is determined whether or not the transistor of the fire determination unit has been turned on continuously plural times in synchronization with the pulse output of the oscillation circuit, and it is determined that the transistor has been continuously turned on. When this is done, the detection output is sent to the fire signal sending unit. Also, when heat is generated by fire,
The heat-sensitive element of the heat detection section outputs a detection output, and when the detection output reaches a predetermined level, the heat / fire discrimination section outputs the detection output to the storage circuit and sends it to the fire signal section as described above. In the fire signal transmitting section, the fire signal transmitting switching element is turned on by the detection output, and transmits a fire signal to the fire receiver. At this time, the operation indicator changes from blinking lighting to continuous lighting.

When the sensitivity is adjusted, the variable resistor for output adjustment is adjusted so that the light-receiving amplification output when there is no smoke in the dark box of the light-receiving unit 20 becomes a predetermined value. Scattered light generated on the inner wall of the dark box when the light emitting element for smoke detection emits light.

Next, a reflection plate which produces light reflection equivalent to smoke of a predetermined density is placed in the dark box, and the variable resistor for adjusting the reference voltage is adjusted so that the transistor for fire discrimination of the fire discrimination unit is turned on.

The power supplied from the fire receiver to the detector enters the constant voltage circuit and receives the constant current action of the constant current circuit, so that the current flowing through the Zener diode is always kept constant.

[0019]

An embodiment of the present invention will be described with reference to the accompanying drawings. The light emitting section 10 includes a smoke detecting light emitting element L1, transistors Q13 to Q15, resistors R27 to R33, and a capacitor C
12 to C15. In the light emitting section 10, the transistors Q13 and Q15 and the resistors R27 and R2
8, R30 to R33 and capacitors C12, C14, C1
5 form an oscillation circuit. This oscillation circuit supplies a pulse output to the light emitting element L1.

The transistor Q14, the resistor R29, the capacitor C13 and the diode D2 constitute a pulse width expanding circuit 12. This circuit 12 expands the pulse width of the pulse output of the oscillation circuit and supplies the pulse width to the operation indicator L2 of the fire signal transmitting unit 50.

The light receiving section 20 includes a light detecting element PD for smoke detection, transistors Q1 to Q4, resistors R1 to R14, a first variable resistor VR1 for sensitivity adjustment, and capacitors C2 to C5, C18.
And The light receiving element PD does not directly receive the light emitted from the light emitting element L1, but receives scattered light of the emitted light.

The transistors Q1 and Q2 and the resistors R1 to R6
, A first sensitivity adjusting variable resistor VR1 and a capacitor C2,
C18 constitutes a first-stage amplifier circuit. This amplifying circuit amplifies the light receiving output of the light receiving element PD, and the variable resistor VR1 is a first sensitivity adjusting variable resistor which forms a feedback resistor of the amplifier circuit.

Transistors Q3, Q4 and resistors R8-R1
4 and the capacitors C3 to C5 constitute a second-stage amplifier circuit. This amplifier further amplifies the output of the first-stage amplifier.

The smoke / fire determining unit 30 includes a transistor Q7, resistors R18 to R20, a variable resistor VR2, and a capacitor C8.
And Variable resistor VR2 and second fixed resistor R1
8, the first fixed resistor R19 constitutes a divided resistor circuit (series resistor circuit).

This variable resistor VR2 is a second variable resistor for sensitivity adjustment to which the amplified light output of the light receiving section 20 is supplied. The transistor Q7 has a base and an emitter connected to both ends of the second fixed resistor, and is a fire discriminating transistor that is turned on and off by the divided voltage of the divided resistor circuit.

The storage circuit 40 includes a transistor Q16 and a resistor R36, a current limiting resistor R37, a resistor R38, a capacitor C17, a D-type flip-flop (D-FF) IC1,
IC2. The output of the transistor Q7 of the fire determination unit 30 and the output of the oscillation circuit of the light emitting unit 10 are connected to the circuit 40.

The circuit 40 determines whether or not the transistor Q7 of the fire determination unit 30 has been turned on continuously plural times in synchronization with the pulse output of the oscillation circuit. When it is determined that the transistor Q7 has been turned on, A detection output is generated. VDD is connected to the + power supply terminals of D-FFIC1 and D-FFIC2,
S is connected to the-power supply terminal.

The fire signal transmitting section 50 includes a silicon controlled rectifier Q11, a transistor Q12, an operation indicator L2, a zener diode Z2, and resistors R23 to R26. The rectifier Q11 is turned on by the detection output of the storage circuit 40.
And are connected in series.

The transistor Q12 is turned on when the voltage detection circuits Z2 and R26, which detect that the voltage applied to the operation indicator L2 has become equal to or higher than a predetermined voltage, detect the predetermined voltage, and turn on the operation indicator with the voltage equal to or higher than the predetermined voltage. This prevents voltage from being applied.

The constant voltage circuit 60 includes a transistor Q9, a junction type field effect transistor Q10, a resistor R22 and a zener diode Z1. This constant voltage circuit 60
Supplies power to the light emitting unit 10, the light receiving unit 20, the smoke fire determining unit 30, the heat fire determining unit of the heat detecting unit 90, and the storage circuit 40.

The transistor Q9 has a constant current circuit 62 between the collector and the base, and the Zener diode Z1 is connected between the base of the transistor Q9 and the ground terminal. The constant current circuit 62 includes a junction field effect transistor (FET) Q10 having a drain connected to the collector of the transistor Q9 and a gate connected to the base of the transistor Q9;
And a resistor connected between the source and the gate of 0.

The sensor output circuit 70 includes a transistor Q6
And resistors R15 and R16. Transistor Q
The base 6 is connected to a connection point P between the output terminal of the light emitting section 10 and the divided resistance circuit of the smoke and fire determining section 30, and its emitter is grounded via an output resistor R16.

The test circuit 80 includes a transistor Q5, a capacitor C6, a diode D1, and a reed switch RS which closes when a magnet approaches. The switching element Q5 is provided in parallel with the reed switch RS, and is turned on by a test signal from outside the sensor.

Reed switch RS and switching element Q
5 is provided in parallel with the gain control resistor R10 of the second-stage amplifier circuit of the light receiving unit 20.

The heat detecting section 90 includes heat detecting elements TH for detecting heat, comparators ICT1 and ICT2 composed of operational amplifiers, transistors QT1 and QT2, and resistors RT1 to RT11. The thermosensitive element TH produces an output in accordance with the detected physical quantity of heat. As the element, for example, a negative thermistor is used. This heat detection unit 90 includes:
A disconnection detecting unit that detects disconnection of the heat-sensitive element and a short circuit that short-circuits both ends of an operation indicator of the fire signal transmitting unit based on a disconnection detection output of the disconnection detecting unit are provided.

DB is a non-polarizing diode bridge circuit. The terminals 1, 2, and 3 are terminals for sending and connecting a pair of power / signal lines (not shown), and the terminals 2, 3 are short-circuited so as to connect one power / signal line inside the sensor.

A terminal 4 is an input terminal for a test signal (test voltage), and terminals 5 and 6 are terminals for outputting an analog light receiving output of the light receiving section 20. 1 and 2 show the connection terminal a
To e constitute one circuit as a whole.

The operation of this embodiment will be described. For example, when the power is turned on to the sensor due to a fire recovery, D-
The capacitor C17 that supplies the power for operation to the FFIC1 and the D-FFIC2 is connected to the current limiting resistor R37 through τ =
Charged with the time constant of R37 × C17 and D-FFI
The voltage across the capacitor C17 is applied to C1 and D-FFIC2.

By the way, D-FFIC1 D-FFIC
2 is unstable when the power is turned on, and DF
There is a case where an L output is generated from the output terminal Q2 of the FIC2 to the fire signal transmitting unit 50, that is, a state where there is no output signal, and a case where an H output is generated, that is, a state where there is an output signal.

When the output terminal Q2 of the D-FFIC2 has an L output, the capacitor C17 is charged to a predetermined voltage as it is. When the output terminal Q2 of the D-FFIC2 has an H output, an H output whose current value is limited by the current limiting resistor R37 is generated from the output terminal Q2.

On the other hand, the capacitor C17 is a current limiting resistor R
The charges are charged to a voltage determined by the division ratio between the resistor 37 and the resistors 23, R24, and R25. Therefore, the current required for turning off the device Q11 is not supplied from the D-FFIC 2 to the gate of the silicon controlled rectifying device 11, so that the device 11 does not turn on.

The capacitor C12 of the light emitting section 10 is charged through a resistor R27 by power supplied from a fire receiver or a repeater (not shown) through the terminals 1 and 2 (3). When the charging voltage reaches the sum of the voltage divided by the resistors R32 and R33 and the base-emitter voltage V _BE of the transistor Q15 (hereinafter referred to as the light emission reference voltage), the transistor Q15 is turned on, and the transistor Q13 is turned on.
Also turns on.

When the transistor Q13 is turned on, the electric charge of the capacitor C12 is discharged through the resistor R28 and the smoke detecting light emitting element L1, so that the light emitting element L1 emits light and the transistor Q14 is also turned on. At the same time, the capacitor C13 is charged by the discharge current.

When the transistor Q15 turns on, the transistor Q16 of the storage circuit 40 turns on, and a clock signal is input to the D-FFIC1 and the D-FFIC2 as a light emission synchronization signal. While the transistor Q13 is ON, the capacitor C15 is charged by the base current of the transistor Q15, and the transistor Q15 is turned off by this charging voltage, for example, at an interval of 3 seconds.
It is chosen to emit for 00 μs.

The transistor Q14 is connected to the transistor Q1
3 is turned on by the discharge current of the capacitor C12, and when the transistor Q13 is turned off, the capacitor C13 stops charging, and the capacitor C13 stores the electric charge charged up to that time by a transistor provided in parallel. Discharge occurs through the resistance of Q14, and the discharge current keeps the ON state.

Then, the on-state transistor Q14
Supplies the charge of the capacitor C12 to the operation indicator light L2 of the fire signal sending unit 50 as an operation power source. In this embodiment, the ON time of the transistor Q14 is selected to be, for example, 1 ms, which allows a person to visually recognize that the operation indicator L2 is turned on.

The light receiving section 20 receives the scattered light due to the light emission of the smoke detecting light emitting element L1 by the smoke detecting light receiving element PD, amplifies the received light output by a two-stage amplifier circuit, and fires the light.
Output to 0. The transistor Q7 of the fire determining unit 30
The received light amplification output is a resistor R19, a reference voltage adjusting variable resistor V
When the base voltage divided by R2 and the resistor R18 is lower than the base-emitter voltage, it remains off, outputs a high (H) signal to the storage circuit 40, and turns on when it becomes higher than the base-emitter voltage. A low (L) signal is output to the storage circuit 40 as a fire determination signal.

The D-FFIC1 of the storage circuit 40 outputs the output terminal when the H signal is input to the input terminal D1 when the clock signal (the synchronization signal from the light emitting unit 10) is input from the transistor Q16 to the clock terminal CL1. An H signal is generated from Q1, and an L output is generated from the inverted output terminal / Q1. That is,
The storage circuit 40 is reset. As a result, D-FFIC
No output signal is output from the second output terminal Q2, and thus the capacitor C17 resumes charging through the current limiting resistor R37 and is charged to a predetermined voltage.

When a clock signal is input to the clock terminal CL2, the D-FFIC2 outputs the output terminal Q of the D-FFIC1.
The L output is output from the output terminal Q2 to the fire signal transmitting unit 50 by the L output of 1. Therefore, the silicon control rectifier Q11 of the sending section 50 maintains the off state.

When a clock signal is input to the clock terminal CL1, the D-FFIC1 of the storage circuit 40 has an input terminal D-FFIC1.
When an L signal, which is a fire discrimination signal, is input to 1, an L output is generated from the output terminal Q1 and an H output is generated from the inverted output terminal Q1. On the other hand, D-FFIC2 has a clock terminal CL.
When the clock signal is input to the second terminal 2, the inverted output terminal Q2 of the D-FFIC1 still has the L output, and the output terminal Q2 keeps the L output.

In this state, if a clock signal is input to the clock terminal CL1 of the D-FFIC1 and the L signal, which is a fire discrimination signal, is input again to the input terminal D1, D-FFIC1
FFIC2 is an inverted output terminal of D-FFIC1 and H of Q1.
The output causes an H output from the output terminal Q2.

The charge stored in the capacitor C17 is discharged as an output signal by the H output of the D-FF 1C2, and the fire signal sending unit 5 is output by the output signal of the discharge current.
0, the silicon controlled rectifier Q11 turns on, and the terminals 1 and 2
(3) Send out a fire signal. As a result, the operation indicator L2 switches from intermittent lighting by the pulse output of the light emitting unit 10 to continuous lighting by the fire signal.

During the transmission of the fire signal, the power supply voltage supplied from the receiver or the like fluctuates and rises, and the current flowing in the series circuit of the resistor R25 and the operation indicator L2 increases. When the drop exceeds the Zener voltage of Zener diode Z2, Zener diode Z2 conducts and transistor Q12 turns on. Thereby, the operation indicator L2
Current flowing through the power supply voltage is prevented from increasing more than necessary due to fluctuations in the power supply voltage.

When a clock signal is input to the clock terminal CL1 of the D-FFIC1, the input terminal D1 changes from the L signal to the H level.
When the signal has changed to a signal, that is, when the fire discrimination unit 30 does not generate a discrimination output, the output terminal Q1 of the D-FFIC1 changes from the L output to the H output, and the inverted output terminal / Q1 changes from the H output to the L output. Changes to output.

The output terminal Q1 of the D-FFIC1 is L
The output changes from the output to the H output, the D-FFIC2 is reset, and the output terminal Q2 maintains the L output. Therefore, if the fire discrimination unit 30 outputs the discrimination signal only once due to any transient phenomenon, the accumulation circuit 40 does not generate an output, and the transmission unit 50 does not transmit the fire signal.

When the power supply from the receiver or the like is temporarily cut off in order to restore the fire detector that has been operated, the silicon control rectifier Q11 is restored and the storage circuit 4 is restored.
D-FFIC1 and D-FFIC2 of 0 are also set to the initial state. The heat detecting section 90 is supplied with the operating power from the pulse width expanding circuit 12 of the light emitting section 10 as described above.

When the power is supplied as an expanding pulse from the pulse width expanding circuit 12 of the light emitting section 10, the heat detecting section 90 detects the change in resistance due to the temperature of the thermistor TH as a fire determining comparator I.
Monitoring is performed by the CT1 and the failure detection comparator ICT2. The input voltage at one end of the fire determination comparator ICT1 is thermistor TH
When the resistance becomes lower than the reference voltage for fire determination at the + terminal (the divided voltage of the resistors RT3 and RT4) due to the decrease in resistance due to the heat of the fire, the comparator ICT1 generates an H output. The transistor QT1 is turned on by the H output, and the heat detection unit 90 outputs an L output fire determination signal to the storage circuit 40.

The storage circuit 40 includes a heat detecting section 90 as described above.
When the fire discrimination signal is input twice consecutively, the H output is output to the fire signal transmitting unit 50. Also, pulse width expansion circuit 1
If the thermistor TH is disconnected during the operation when power is supplied from the power supply 2, the potential at the connection point between the resistors RT2 and RT11 becomes higher than the reference voltage for disconnection determination by the divided resistors RT5 and RT6. As a result, the failure detection comparator ICT2 generates an H output, and the transistor QT2 turns on.

When the transistor QT2 is turned on, both ends of the operation indicator L2 of the fire signal sending unit 50 are short-circuited, and the operation indicator L2 stops intermittent lighting by the pulse signal output from the pulse width expanding circuit 12 of the light emitting unit 10. To indicate that a failure has occurred.

To test whether or not the fire detector operates, a test signal is supplied to the terminal 4 from a receiver (not shown), for example, to turn on the transistor Q5 of the test circuit 80,
Alternatively, a magnet (not shown) is brought close to the sensor to turn on the reed switch RS. Thereby, 2 of the light receiving unit 20
The resistor R11 is connected in parallel to the resistor R10 of the second-stage amplifier circuit, and the gain of the second-stage amplifier circuit increases. Then,
The light receiving amplification output of the light receiving element PD by the light emission of the light emitting element L1 when there is no smoke is an output necessary for operating the transistor Q7 of the fire discrimination unit 30.

If there is no abnormality in the light emitting element L1, the light receiving element PD, the amplifier circuit, etc., the smoke / fire determining unit 30 generates a fire determining output.
When 0, the fire signal sending circuit 50 operates to send a fire signal, and the operation indicator L2 switches to continuous lighting.
If any of these parts and circuits are abnormal, the sending circuit 50 does not send out a fire signal and the operation indicator L2 does not light continuously.

To adjust the sensitivity of the thermoelectric fire detector, first,
A tester such as a voltmeter is connected to the terminals 5 and 6, and the output adjustment variable resistor VR1 is adjusted so that the received light amplification output becomes a predetermined value when there is no smoke in the dark box of the sensor (not shown). At this time, the received light amplified output is the smoke detection light emitting element L
1 is an output that receives scattered light generated on the inner wall of the dark box when 1 occurs.

Next, smoke having a predetermined density, for example, smoke having a density of 10% / m, or a reflection plate which generates light reflection equivalent to the smoke is inserted into the dark box.
The reference voltage adjusting variable resistor VR2 is adjusted so that 7 turns on. When adjusting the variable resistance VR2, the smoke density and the reflection plate to be put into the dark box do not need to use the smoke density determined to be a fire or a reflection plate equivalent thereto.

That is, each sensor has its own variable resistance V
By adjusting R1, the received light amplified output output from the amplifier circuit is adjusted to a predetermined value. As a result, variations in the light-receiving amplification output due to variations in circuit components such as the light-emitting element L1, the light-receiving element PD, and the amplifier circuit between the sensors are corrected.

The light receiving amplification output is proportional to the smoke density flowing between the light emitting element L1 and the light receiving element PD. Therefore, a voltage drop corresponding to this arbitrary smoke density may be generated in the resistor R18 of the fire determination unit 30 when the reflector generates an arbitrary smoke density or reflected light equivalent thereto.

Therefore, when the discrimination level is adjusted by the reference voltage adjusting variable resistor VR2, the smoke density in the dark box or the equivalent reflection amount of the reflector may be any smoke density. The reference voltage adjusting variable resistor VR2 is adjusted so that the voltage drop generated in the series resistor circuit of R18 and the resistor R19 becomes a voltage drop corresponding to this arbitrary smoke density. As a result, when smoke of a predetermined concentration determined to be a fire flows into the dark box, a voltage drop required to turn on the transistor Q7 occurs in the resistor R18 of the fire determination unit 30 due to the amplified light reception output at that time. .

When the temperature rises, the output of the smoke detecting light emitting element L 1 of the light receiving section 10, that is, the amount of emitted light decreases, but when the temperature of the transistor Q 6 of the sensor output circuit 70 rises, the base-emitter voltage V _BE rises. descend. Therefore, the transistor Q6 compensates for a decrease in the output of the light emitting element L1. The transistor Q6 uses the base-emitter voltage V _BE to enlarge the sensor output and output it to the test circuit 80. As a result, even a slight change in the sensor output is enlarged and output to the output terminals 5 and 6, so that the sensitivity adjustment by the output adjustment variable resistor VR1 and the reference voltage adjustment variable resistor VR2 and the check of the sensitivity change can be easily performed. .

The constant voltage circuit 60 includes an FET Q10 and a resistor R
The constant current operation of the constant current circuit 62 comprising the constant voltage circuit 22 keeps the current flowing through the zener diode Z1 constant and keeps the current consumption in the constant voltage circuit 60 constant. Therefore, even if the power supply voltage changes, the current consumption of the constant voltage circuit 60 does not change.

The storage circuit 40 has a D-FF when the power is turned on.
To prevent the IC1 and IC2 from malfunctioning and operating the fire signal transmission circuit 50, the current limiting resistor R37 is used.
And a series circuit of a capacitor C17. The capacitor C17 has a role of supplying power to the D-FFIC1 and IC2, and the current limiting resistor R37 controls the D-FFIC1 and IC2 until the charged voltage reaches a predetermined voltage.
The current supplied to FFIC1 and IC2 is limited.

Thus, immediately after the power is turned on, the D-FFI
The state of C1 and D-FFIC2 is unstable and D-FFIC
2 generates an H output from the output terminal Q2, the D-FFIC2
Does not obtain a current necessary for triggering (operating) the silicon controlled rectifier Q11.

When a clock pulse (synchronous signal) is input from the light emitting section 10 and the output terminal Q2 of the D-FFIC2 is set to the L output, the capacitor C17 is charged up. As a result, malfunction at power-on is prevented.

In the above embodiment, a pulse of about 1 ms, which is obtained by expanding the output of the oscillation circuit from the light emitting section 10 by the pulse width expanding circuit 12, is supplied to the heat detecting section 90 as an operating power supply. When the operation indicator L2 does not need to be intermittently turned on, a pulse of about 100 μsec of an oscillation circuit for turning on the light emitting element of the light emitting unit 10 in a pulsed manner may be divided and supplied to the heat detecting unit 90. Good.

The above embodiment relates to a normal fire detector which sends out a fire signal when the light receiving section 20, ie, the fire phenomenon detecting section detects a fire phenomenon such as smoke determined to be a fire. In the case of an analog fire detector that sends out a signal corresponding to the physical quantity of the fire phenomenon detected by the sensor, the configuration is as follows.

That is, instead of the fire discrimination unit 30, A
/ D (analog / digital) converter, a converter for converting a digital signal read from the converter into a form suitable for signal transmission and outputting the converted signal, for example, a parallel-serial converter, an A / D converter, and a parallel-serial A control circuit that controls the operation of the converter and a signal processing circuit that includes a control circuit and the like are provided.

Further, instead of the fire signal transmitting section 50,
A signal transmitting unit having a transistor or the like which is turned on / off by a serial code signal output from the parallel-serial converter is provided. Then, the constant voltage circuit supplies a constant voltage to the fire event detection unit and the signal processing circuit.

In the above embodiment, the storage circuit 40 having two stages, ie, two D-type flip-flops D-FFIC1 and D-FFIC2 has been described.
Is a three-stage type as shown in FIG. 3, that is, three D-type flip-flops D-FFIC1, D-FFIC2, and D-FFI.
C3 may be formed by continuous connection. In the two-stage storage circuit of the above embodiment, the storage circuit 40 operates and generates an output signal when the fire determination unit 30 generates a fire determination output twice consecutively, whereas in the three-stage storage circuit, , Fire discriminator 3
The storage circuit generates an output signal when 0 is generated three consecutive times for the fire discrimination output.

In the above embodiment, the smoke fire discriminating section 30
Made a fire discrimination with transistor Q7,
The fire determination may be performed by the comparator in the same manner as the fire determination comparator ICT1 of the heat detection unit 90. In this case, the output of the light receiving section 20 is connected to one input terminal of the comparator, and the other input terminal includes a first fixed resistor, a second fixed resistor, and a variable resistor for adjusting the reference voltage. The reference voltage generation point of the configured reference voltage generation circuit may be connected, and a reference voltage measurement terminal may be connected to the reference voltage generation point. .

[0078]

As described above, the present invention has the following remarkable effects. (1) Since the amplifier circuit having the variable resistor for adjusting the output and the variable resistor for adjusting the reference voltage are provided, the amplified output is adjusted to a predetermined output value by the variable resistor for adjusting the output, and the reference voltage is adjusted. The switching level of the fire determining unit can be adjusted to a predetermined value by the variable resistor.

Therefore, the amplification output of the amplifier circuit of each photoelectric smoke sensor can be set to the same value, and the switching level of the fire determination unit of each photoelectric smoke sensor can be set to the same value. The sensitivity adjustment of the thermoelectric fire detector is simplified.

Further, since the received light amplified output of the amplifier circuit of each photoelectric smoke detector has the same value, it is easy to know how much the detected output of the detector in the smokeless state has changed from the initial detected output. be able to.

(2) In synchronism with the pulse output of the light emitting section, it is determined whether or not the transistor of the smoke fire determining section or the heat fire determining section is continuously turned on a plurality of times, and the transistor is continuously turned on a plurality of times. Since a resistor for limiting the current is provided in the storage circuit that sends the detection output to the fire signal sending unit when it is determined that the fire signal sending unit does not malfunction, the fire signal sending unit does not malfunction when the power is turned on.

(3) Since a transistor having a constant current circuit between the collector and the base and a constant voltage circuit having a zener diode connected between the base of the transistor and the ground terminal are provided, the collector of the transistor of the constant voltage circuit is provided. Even if the power supply voltage from the fire receiver applied between the diode and the cathode of the Zener diode is different, the current flowing through the Zener diode will always be constant due to the action of the constant current circuit provided in series with the diode. . Therefore, the current consumption of the constant voltage circuit becomes constant regardless of the level of the power supply voltage.

(4) The light emitting section includes a pulse width expanding circuit for expanding and outputting a pulse width of a pulse output of the oscillation circuit, and an output of the pulse width expanding circuit indicates an operation of the fire signal transmitting section. Since it is connected to the lamp, the pulse output of the oscillation circuit that controls the emission of the light emitting element for smoke detection is expanded by the pulse width expansion circuit, and is supplied to the smoke detection unit as an operation power supply, and the operation display is performed by the expanded pulse. The light comes on. Therefore, when the oscillation circuit stops oscillating and the smoke detection and the heat detection cannot be performed, the indicator light also stops blinking and turns on, so that it is possible to know that an abnormality has occurred in the sensor.

(5) The heat detecting section intermittently performs heat detection because the light emitting pulse current is shunted from the oscillation circuit of the light emitting section and supplied as the operating power supply. Therefore, the current consumption by the heat detection unit is significantly reduced. Further, it is not necessary to separately provide an oscillation circuit for the heat detection unit.

[Brief description of the drawings]

FIG. 1 is an electric circuit diagram showing an embodiment of the present invention, showing an upper half thereof.

FIG. 2 is an electric circuit diagram showing an embodiment of the present invention, showing a lower half thereof.

FIG. 3 is an electric circuit diagram showing another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Light-emitting part 12 Pulse width expansion circuit 20 Receiving part 30 Fire discrimination part 40 Storage circuit 50 Fire signal sending part 60 Constant voltage circuit 62 Constant current circuit 70 Sensor output circuit 80 Test circuit

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-55-74692 (JP, A) JP-A-2-112096 (JP, A) JP-A-61-271597 (JP, A) JP-A-1- 166289 (JP, A) JP-A-61-148598 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G08B 17/00-17/12

Claims (21)

(57) [Claims] 1. A light emitting section comprising a light emitting element for smoke detection, an oscillation circuit for supplying a pulse output to the light emitting element, and a light emitted from the light emitting element for smoke detection instead of being directly received. A light-receiving section having a smoke detection light-receiving element for receiving the scattered light of the light, an amplification circuit for amplifying and outputting the light-receiving output of the light-receiving element, and a light-receiving amplification output of the amplification circuit being higher than a predetermined level A photoelectric smoke detection unit including a smoke fire detection unit that outputs a smoke fire output when the heat reaches the detection unit; a heat detection element for generating an output corresponding to the physical quantity of the detected heat; and detection of the heat detection element A heat fire discriminator that outputs a heat fire output when the output reaches a predetermined level, wherein the pulse output is shunted and supplied from the oscillation circuit as a monitoring power supply. And the smoke fire output of the smoke fire determination unit and the heat fire Thermal photoelectric type fire detector, characterized in that it comprises a; and fire signal transmitting section for transmitting a fire signal operates by either fire output of the heat fire output determination unit. 2. The light emitting unit according to claim 1, further comprising a pulse width expanding circuit for expanding and outputting a pulse width of a pulse output from an oscillation circuit, wherein an output of said pulse width expanding circuit is an operation indicator of said fire signal transmitting unit. The thermoelectric fire detector according to claim 1, wherein the fire photoelectric detector is connected to the thermoelectric fire detector. 3. The light emitting section includes a pulse width expanding circuit for expanding and outputting a pulse width of a pulse output of an oscillation circuit, and an output of the pulse width expanding circuit is an operation indicator of the fire signal transmitting section. The thermoelectric fire detector according to claim 1, wherein the thermoelectric fire detector is connected to the heat detector and the heat detector. 4. An amplifier circuit of the light receiving section is provided with an output adjusting variable resistor for adjusting the light receiving amplified output, and the fire determining section is provided with a reference voltage adjusting variable resistor for adjusting a reference voltage. The thermoelectric fire detector according to claim 1, wherein: 5. A disconnection detecting section for detecting disconnection of the heat-sensitive element, and a short-circuit circuit for short-circuiting both ends of an operation indicator of the fire signal transmitting section by a disconnection detection output of the disconnection detecting section. 2. The device according to claim 1, wherein
A thermoelectric fire detector as described. 6. When the smoke fire discriminator detects that a smoke fire output has occurred continuously a plurality of times between the smoke fire discriminator and the fire signal transmitter, a smoke signal is transmitted to the fire signal transmitter. 2. A thermoelectric fire detector according to claim 1, further comprising a storage circuit for outputting a fire output. 7. The fire signal transmission unit according to claim 7, wherein
7. The switching device according to claim 1, wherein a switching element that operates by any of the thermal fire outputs and an operation indicator connected in series with the switching element are provided. 8. Thermoelectric fire detector. 8. A light emitting section comprising: a smoke detecting light emitting element; an oscillation circuit for supplying a pulse output to the light emitting element; and a light emitting section which does not directly receive light emitted from the smoke detecting light emitting element. A smoke detection light-receiving element for receiving the scattered light of the light,
A photoelectric smoke detection unit comprising: a light-receiving unit comprising: a smoke-fire detection unit that outputs a smoke-fire output when the light-receiving amplification output of the amplification circuit reaches a predetermined level or more; A heat detection element for detecting heat, which generates an output according to the following, and a heat fire discriminating section for outputting a heat fire output when the detection output of the heat detection element reaches a predetermined level, A heat detection unit to which the pulse output is shunted and supplied as a monitoring power supply from the oscillation circuit; and whether the transistor of the smoke or heat fire determination unit is turned on a plurality of times continuously in synchronization with the pulse output of the oscillation circuit. A storage circuit that generates a detection output when it is determined that the transistor has been continuously turned on a plurality of times; a fire signal transmission switching element that is turned on by the detection output of the storage circuit; A fire signal transmitting unit including an operation indicator light connected to a column; a constant voltage circuit for supplying power to the light emitting unit, the light receiving unit, the fire determining unit, and the storage circuit, A thermoelectric fire detector, comprising: a transistor having a constant current circuit between a collector and a base; and a constant voltage circuit having a zener diode connected between the base of the transistor and a ground terminal. 9. A sensor output circuit comprising a transistor having a base connected to a connection point between an output terminal of the light receiving section and a split resistor circuit of the fire discriminating section and having an emitter grounded via an output resistor. The thermoelectric fire detector according to claim 8, wherein 10. A test circuit comprising a reed switch turned on by magnetism from outside the sensor and a switching element provided in parallel with the reed switch and turned on by a test signal from the outside of the sensor. 9. The thermoelectric fire according to claim 8, wherein a parallel circuit of a reed switch and a switching element of the test circuit is provided in parallel with a gain control resistor of a second-stage amplifier circuit of the light receiving unit. sensor. 11. A fire signal transmitting unit comprising a transistor in parallel with an operation indicator, a zener diode provided between a collector and a base of the transistor, and a resistor connected between a base and an emitter. The fire photoelectric detector according to claim 8, characterized in that: 12. An oscillation circuit for generating a pulse output; a light emitting element for smoke detection of a light emitting section whose lighting is controlled by the pulse output of the oscillation circuit; and a scattered light of light emitted from the light emitting element for smoke detection due to smoke. A light detecting element for detecting smoke;
An amplifier circuit having an output adjustment variable resistor for amplifying the light receiving output of the light receiving element and adjusting the amplified output to a predetermined output value; and operating when the light receiving amplified output of the amplifier circuit reaches a predetermined level. A smoke fire discriminator having a reference voltage adjustment variable resistor for generating a discrimination output and adjusting a predetermined level for fire discrimination to a predetermined value; and outputting a heat fire output when a detection output of the thermosensitive element reaches a predetermined level. And a fire signal transmitting unit for transmitting a fire signal based on a discrimination output of the fire discriminating unit. 13. An output adjusting variable resistor is provided as a feedback resistor of an amplifier circuit.
2. The thermoelectric fire detector according to 2. 14. A smoke fire discriminating unit, comprising: a series resistor circuit including a first fixed resistor, a second sensitivity adjusting variable resistor, and a second fixed resistor to which an amplified output of the amplifier circuit is supplied; The thermoelectric fire detector according to claim 12 or 13, further comprising a switching transistor having a base and an emitter connected to both ends of the second fixed resistor. 15. A storage circuit to which an output of a transistor of a smoke fire determination unit and a transistor of a heat fire determination unit is connected to an output of an oscillation circuit of a light emitting unit, wherein the storage circuit is a switching element of a fire signal transmission unit. A thermoelectric photoelectric detector, comprising control means for controlling the current to be lower than the driving current. 16. A storage circuit for synchronizing an oscillation circuit with a pulse output to judge whether or not a transistor of a fire judging section has been turned on a plurality of times continuously, and that the transistor has been turned on a plurality of times continuously. The thermoelectric fire detector according to claim 15, wherein a detection output is generated when the determination is made. 17. A light emitting section having a smoke detecting light emitting element, a light receiving section having a smoke detecting light receiving element, a fire determining section for determining a fire based on a light receiving output of the light receiving element, and an output of the fire determining circuit. A storage circuit for preventing the fire signal transmission unit from malfunctioning, and a constant voltage circuit for supplying power to each of the storage circuits, wherein the constant current circuit includes a transistor having a constant current circuit between the collector and the base. And a zener diode connected between the base of the transistor and a ground terminal. 18. A junction field effect transistor having a drain connected to the collector of the transistor and a gate connected to the base of the transistor, and a resistor connected between the source and the gate of the field effect transistor. The thermoelectric fire detector according to claim 16, comprising: 19. A light emitting element for detecting smoke, an oscillation circuit for supplying a pulse output for light emission to the light emitting element, and a pulse width amplification circuit for expanding the pulse width of the pulse output of the oscillation circuit to output an expanded pulse. A light-emitting unit having a smoke detection light-receiving element for receiving scattered light of smoke emitted from the light-emitting element; and a detection output of the light-receiving unit having exceeded a fire determination level. A smoke / fire discriminator that produces a discriminating output at times;
A heat fire discriminator for outputting a heat fire output when the detection output of the heat sensitive element reaches a predetermined level; a fire signal transmitting switching element for transmitting a fire signal according to the discrimination output of the fire discriminator; A fire signal transmitting unit including an operation indicator for displaying an enlarged pulse output of the circuit;
Thermoelectric fire detector equipped with. 20. A light emitting element for smoke detection, an oscillation circuit for supplying a pulse output for light emission to the light emitting element, and a pulse width amplification circuit for expanding the pulse width of the pulse output of the oscillation circuit to output an expanded pulse. A light-emitting portion comprising: a light-receiving portion having a smoke-detecting light-receiving element for receiving scattered light due to smoke emitted from the light-emitting element; and a heat emitting portion when the output of the thermosensitive element reaches a predetermined level. A heat detection unit having a heat fire discrimination unit that outputs a fire output; an analog-to-digital conversion circuit that converts a smoke fire output of the light receiving unit and a heat fire output of the heat fire discrimination unit into a digital signal; A signal transmission unit having a digital signal converted by the circuit and an operation indicator light to which an expanded pulse output of the pulse width expansion circuit is supplied. Fire detector 21. A thermoelectric fire detector according to claim 19, wherein the operation indicator is provided in series with the switching element for transmitting a fire signal.