JPH0441396B2 - - Google Patents

Description

[Detailed Description of the Invention] Conventionally, in a smoke detector in which light emitted from a light emitting element and scattered by smoke from a fire is received by a light receiving element, and smoke is detected by the output of the element, the smoke detector is configured to detect smoke by remote control from the receiver. It is known that operation tests are conducted by increasing the output of the light-emitting element by increasing the output of the light-receiving element due to noise light diffusely reflected on the wall inside the dark box, but this type of photoelectric smoke An important function for smoke detectors is to check whether the light output of the smoke detector is within a normal level range that will not cause false alarms, missed alarms, or late alarms, by remote control from the receiver. None were made available for testing. This invention uses an appropriate configuration of a photoelectric smoke detector that uses scattered light or transmitted light to automatically output light received by the smoke detector based on a signal sent from the receiver through a line connecting the smoke detector and the receiver. The object of the present invention is to obtain a photoelectric smoke detector equipped with a smoke detection function test device that can easily and accurately test whether or not the smoke is within the normal level range and report the result to the receiver through the same line. The present invention will be explained below with reference to embodiments shown in the drawings. FIG. 1 is a circuit diagram of an embodiment of the present invention relating to a scattered light type smoke detector that detects smoke using scattered light;
FIG. 2 is a circuit diagram of the receiver of this embodiment. In Fig. 1, l ₁ and l ₂ are two lines that connect the circuit of the scattered light smoke detector shown in the figure to the receiver circuit shown in Fig. 2, and a and b are the lines l ₁ and l ₂ is the conductor connected through the constant voltage circuit CV, PO ₁ is the conductor a,
a pulse oscillator for synchronizing signals connected between b; 1 a light emitting unit comprising a light emitting element LE such as a light emitting diode and its driving circuit PD connected between conductors a and b;
2 is a light-receiving unit that includes a light-receiving element SB, such as a solar cell, and its output amplifier AM, which receives the scattered light emitted by the light-emitting element LE due to smoke, and 3 is a light-receiving unit that detects the fire level and causes false alarms in a scattered-light smoke detector. In order to determine the upper limit value of the normal level range as the limit value at which the alarm becomes more likely to occur, and the lower limit value of the normal level range as the limit value at which the alarm is more likely to occur, conductors a and b are used.
Of the resistors r ₁ , r ₂ , r ₃ , r ₄ connected in series between
a comparator unit equipped with a comparator CM, which connects the voltage at the connection point between _r1 and _r2 to one terminal on the input side and the output of the amplifier AM of the light receiving unit 2 to the + terminal on the input side, with the voltage at the connection point of r1 and r2 as the operating reference level; is the output of the synchronizing signal pulse oscillator PO ₁ , the output of the comparator CM of the comparator 3 , and the Q output of the monostable multivibrator (hereinafter simply referred to as monostable multi) MM ₂ in the timer circuit 9 , which will be described later, are applied to the input terminal. Input is the output of NOT gate N ₃
AND gate _A1 and NOT gate _N2 in recovery signal generation circuit 8, which will be described later, uses the output of _A1 as set input.
NOR gate NR ₁ cleared by the output of NR 1 ,
_a fire discriminating unit comprising _a latch Lt ₁ formed by NR ₂ ; _The inputs are a pulse oscillator PO ₂ that generates _a
NAND gate NA ₁ and f ₂ pulse output and gate
A signal generation circuit includes a NAND gate NA ₂ which receives the output of NA ₁ as input, and 6 is an output generated when the fire discrimination section 4 detects a fire, and a NOR gate NR ₆ , NR of the smoke detection function discrimination circuit 11 . NOR gate NR ₈ whose input is the output of _{the latch Lt 3 formed} by
, the output of NR ₈ and the gate of signal generation circuit 5
a NOR gate NR ₉ whose input is the output of NA ₂ ;
Diode D ₁ and resistor r ₅ connected between lines l ₁ and l ₂
and a series circuit of a transistor T ₃ having a resistance r ₆ between the base and emitter, and by controlling the conduction of the transistor T ₃ by the output of the gate NR ₉ , a repetition rate f ₁ is applied to the lines l ₁ and l _2. Or it is a transmitting circuit designed to send out a pulse signal of _f2 . circuit 6
The circuit added with a broken line inside is to enable the receiver to identify the sensor that outputs the signal when multiple sensors are connected in parallel to the same line l ₁ and l ₂ . Each sensor is different,
An oscillator PO ₃ that generates pulses with a much higher repetition rate than f ₁ and f ₂ is connected between conductors a and b by a transistor.
T ₅ between the diode D ₁ and the resistor r ₅ , resistor r ₁₈ between the conductor a and the base of T ₅ , resistor r ₁₉ between the base of T ₅ and the collector of T ₃ , the capacitor C ₆
Connected between PO ₃ and the base of T ₅ , the pulse output of PO ₃ modulates each pulse of the pulse signal with the repetition rate f ₁ and f ₂ sent from each sensor to the lines l ₁ and l ₂ . That's what I do. Next, 7 is a receiving circuit that receives a narrow single pulse signal for test start and a wide single pulse signal for recovery sent from the receiver shown in Fig. 2, and conductors a and b. An output line d that comes out from the connection point between resistors r ₇ and r ₈ and capacitors C ₂ and r ₈ and C ₂ connected in series between them and reaches a recovery signal generation circuit 8 and a timer circuit 9 described later, and a line l ₁ A transistor whose conduction is controlled by the voltage at the connection point of resistors r ₉ and r ₁₀ connected in series between , l ₂ , and connected so as to short-circuit the series circuit of r ₈ and C ₂ when conductive. ₈ is a receiving circuit 7.
This is a recovery signal generation circuit that determines that a recovery signal has been received from the receiver and outputs a recovery signal into the sensor.The capacitor C is charged by the output of the receiver circuit 7 through the NOT gate _N1 and the resistor _r11 . ₃ ,
9 is _a timer circuit that operates when _the receiving circuit ₇ receives a test start signal from the receiver, and the output of the circuit 7 is The latch Lt ₂ formed by the NOR gates NR ₃ and NR _{4 set} by Monostable multi with short operating time, in which the output of Lt ₂ is triggered through resistor r ₁₃ and a delay circuit formed by capacitor C ₄ and resistor r ₁₄
MM ₁ and monostable multi-MM ₂ with long operating time
and the outputs of MM ₁ and MM ₂ are applied to the input terminal
It is equipped with AND gates A ₂ and A ₃ . 10 is an operation reference level switching circuit for switching the operation reference level of _the comparator CM in the comparator 3 _;
The series circuit of resistors r ₃ and r ₄ is short-circuited by transistor T ₁ which is made conductive through and resistor r ₁₅ ,
The output of AND gate A ₃ connects diode D ₃ and resistor
Transistor T ₂ conducted through R ₁₆
so that only the resistor _r4 is short-circuited, and the comparison section 3
The operating reference level voltage applied to one terminal on the input side of the comparator CM is the fire level for a scattered light smoke detector when both T ₁ and T ₂ are not conducting, and is the same as when T ₁ is conducting. This is the lower limit of the normal level range, which is the limit value at which a sensor is more likely to cause false alarms or delayed alarms, and the upper limit of the normal level range, which is the limit value at which false alarms are more likely to occur in the same sensor when T ₂ becomes conductive. That's what I do. And 11 is a pulse oscillator PO ₁ for synchronization signal
AND gates A 4 and A 5 which have the output of the comparator CM of the comparator 3 and the output of the AND gates A _{2 and} A ₃ in the timer circuit 9 as inputs, respectively, and the output of _{A 4 as} the set input, R-S flip-flop circuit whose reset input is the output of OR gate _R1 which inputs the output of _A5 and the output of recovery signal generation circuit 8 .
FF ₁ and the Q output of FF ₁ become the D input, which will be described later.
The clock signal generated by NOR gate _NR5 becomes the CP input, and the output of circuit 8 becomes the reset input.
Delayed flip-flop circuit FF ₂ and the Q output of the monostable multi MM ₂ of the timer circuit 9, and the voltage of the capacitor C ₅ charged through the resistor r ₁₇ by the same Q output is applied through the resistor R ₁₈ .
NOR gate NR 5 as a clock signal generator which takes the output of NOT gate N ₄ as an input, and NOR gates NR ₆ and NR which take the output of NR ₅ as a set input and are cleared by the output of the recovery signal generation circuit ₈ . This is a smoke detection function discrimination circuit equipped with a latch _Lt3 formed by ₇ . In Figure 2, E is a DC power supply, M is a detection circuit for abnormal signals including fire signals with a repetition rate of f ₂ , and N is a repetition rate.
f ₁ normal signal detection circuit, X is test start switch
A relay that operates when SW ₁ is closed, Y is a relay that operates when recovery switch SW ₂ is closed, TS is a test start signal generator that operates when contact x ₁ of X is closed,
RS is a recovery signal generator that operates when Y contact y ₁ is closed, L _a1 is a fire indicator light that lights up through X break contact x ₄ and M make contact m ₁ , L _a2 is X make contact x ₃ and M make contact m ₂ and L _a3 lights up through make contact x ₃ and N.
The normal indicator light lights up through the make contact N ₁ ,
T is _{a timer} that starts operating when contact _{x5 of} This is an accident indicator light that indicates an accident such as a disconnection of wires ₁ and _l2 . First, the operation of each part of this embodiment in the normal monitoring state and in the event of a fire will be explained with reference to the time chart shown in FIG. 3A. 1 in Figure 3A
is the smoke concentration, 2 is the voltage of the lines l ₁ and l ₂ ,
As shown at the left end of 1, under normal monitoring conditions with no smoke, the voltage on lines l ₁ and l ₂ of 2 is _EV . The voltage on the output line d of the receiving circuit 7 is L as shown at the left end of 3 because the transistor T ₄ is conductive. Therefore, in the recovery signal generating circuit 8 , the output of its NOT gate _N1 becomes H, and the capacitor _C3 is charged by the output, and the output of the NOT gate _N2 becomes L, and recovery is performed as shown in the left end of 4. Generates no signal. Also, in the timer circuit 9 , the NOR gate NR ₃ ,
Since the input of the latch Lt ₂ formed by NR ₄ is L, its output is also L as shown at the left end of 5.
Monostable multi-MM ₁ without clock signal,
As shown in 6 and 7, the Q output of MM ₂ is L, the Q output of MM ₁ is H, and the outputs of AND gates A ₂ and A ₃ are both L. Therefore, both transistors T ₁ and T ₂ of the operation reference level switching circuit 10 are not conductive, and the comparator 3
The operating reference level of the comparator CM is at the fire level _L3 , which is determined by the division ratio of the resistances _r1 and _r2 + _r3 + _r4 , as shown by the broken line in 11. Then, each time the pulse oscillator PO ₁ outputs the synchronization signal shown in 10, the light emitting element LE is activated through the drive circuit PD of the light emitting unit 1 .
emit light in the same way, and the light-receiving element of the light-receiving section 2 is affected by the diffusely reflected light from the inner wall of the dark box caused by the light emission.
The output amplifier AM of SB produces the received light output shown at 11. However, since this received light output is below the fire level _L3 in the absence of smoke, the comparator in comparator 3
CM produces no output as shown at the left end of 12. Furthermore, in the fire discriminator 4 , the output of the NOT gate _N3 is H because the Q output of the monostable multi _MM2 of the timer circuit 9 is L, but the output of the comparator CM is L.
Therefore, the output of AND gate _A1 becomes L,
Latch Lt ₁ formed by NOR gates NR ₁ and NR ₂
The input of NR 2 is L, and the output of NR ₂ is also L as shown at the left end of 13. On the other hand, smoke detection function discrimination circuit 11
Then, since the output of the comparator CM of the comparator 3 is L, the outputs of the AND gates A ₄ and A ₅ are L, and therefore,
The output of the OR gate _R1 is also L, the Q output of the R-S flip-flop circuit _FF1 is L as shown in 14, the Q output of the monostable multi-MM ₂ of the timer circuit 9 is L, and the Q output of the NOT gate _N4 is L. Since the output is H, the output of the NOR state NR ₅ as a clock signal generator is also L as shown in 16, and the Q output of the D-type flip-flop circuit FF ₂ is also L as shown in 15.
Latch Lt ₃ formed by NOR gates NR ₆ and NR ₇
The output of is also L as shown in 17. Therefore, in the signal generating circuit 5 , the pulse oscillator PO ₂ generates a pulse output with a repetition rate f ₁ shown in 18 and a pulse output with a repetition rate f ₂ shown in 19, and the output of the NAND gate NA ₁ is f ₁
The pulse output of NA 2 and the Q output L of circuit FF ₂ result in a continuous H, and the output of NA ₂ is the same as the pulse output of f ₂ .
Due to the continuous H output of NA ₁ , as shown in 20, the pulse output of PO ₂ has an opposite phase to the pulse output of f ₂ , and in the transmitting circuit 6 , the output of NOR gate NR ₈ is H, so The output of NOR gate NR ₉ is low as shown on the left side of 21 and transistor T ₄
is not conductive, and no output is produced on the lines l ₁ and l ₂ as shown at the left end of 2. Next, as shown in the middle of 1, when smoke from the fire enters the dark box and its concentration exceeds the fire level _L3 , when the light emitting element LE emits light, the output amplifier AM of the light receiving element SB is as shown in 11. When the pulse output exceeds the fire level _L3 , the comparator CM generates the pulse output shown in 12 corresponding to the pulse output, and the AND gate
_A1 generates a pulse output corresponding to the output of CM using this pulse output, the synchronization signal shown at 10 issued by the oscillator _PO1 , and the H root output of the NOT gate _N3 . This pulse output allows the NOR gate NR ₁ ,
The output of latch Lt ₁ formed by NR ₂ is set as shown at 13 and NR ₂ produces a fire output.
In addition, due to the fire output of NR ₂ , the output of the NOR gate NR ₈ of the transmitting circuit 6 becomes L, and this L output and the pulse output of the repetition rate f ₂ shown in 20 of the NAND gate NA ₂ of the signal generating circuit 5 cause nOR. Gate NR ₉ is 2
The transistor T ₃ produces a pulse output of f ₂ shown in 1.
An abnormal signal with a repetition rate f ₂ as shown in 2 is sent to the lines l ₁ and l ₂ as a fire signal. When this fire signal is detected by the abnormal signal detection circuit M of the receiver shown in Fig. 2, the contact _m1 closes and the fire indicator light L _a1
lights up. To restore a detector that is emitting a fire signal like this, turn on the receiver's recovery switch.
SW ₂ is closed to operate relay Y, contact y ₁ is closed to operate restoration signal generator RS, and a restoration signal shown as P ₂ in FIG. 32 is sent to lines l ₁ and l ₂ . This signal P ₂ then causes the transistor T ₄ of the receiving circuit 7 in the sensor to cease conducting, and the circuit 7 produces an output P ₂ ' shown at 3 on its output line d. As a result, the output of the NOT gate _N1 of the recovery signal generation circuit 8 becomes L, and the charge in the capacitor _C3 is discharged through _N1 .
When the input of NOT gate _N2 becomes L, _N2 outputs a clear signal c as shown in 4. On the other hand, before N ₂ issues a clear signal, the output P ₂ ' of circuit 7 is output to timer circuit 9.
When the input terminal of the latch Lt ₂ is formed by the NOR gates NR ₃ and NR ₄ , Lt ₂ is set and NR ₄ produces an H output as _shown in ₅ . 5 is charged through the resistor r ₁₃ as shown by the broken line, and before the voltage reaches the level that becomes the clock signal, the circuit 8 outputs the clear signal c of 4, so this signal c causes Lt ₂ to Clearing its set state, the charge on _C4 is discharged through resistor _r14 and no longer produces a clock signal. When the detector is restored as described above, the smoke density is below the fire level L ₃ as shown in 1, and the clear signal c of 4
As a result, the set state of the latch Lt ₁ formed by the NOR gates NR ₁ and NR ₂ is cleared, the fire output of NR ₂ is stopped as shown in 13, and the transmitting circuit 6
The output of NOR gate NR ₈ becomes H, and NR ₉ becomes 2
As shown in 1, the output is stopped and no fire signal is sent to the lines l ₁ and l ₂ . Therefore, in the receiver shown in FIG. 2, the abnormal signal detection circuit M no longer detects the fire signal, so the contact _m1 opens and the fire indicator L _a1 goes out. Next, the operation of each part during a test when the output of the light receiving output amplifier AM in the light receiving section 2 is within the normal level range will be explained with reference to the time chart shown in FIG. 4A. First, turn on the receiver test start switch shown in Figure 2.
When _{SW 1 is} closed _{, relay}
A test start signal shown as P1 is sent to ₂ in Figure A, and the transistor in the receiving circuit 7 of the sensor shown in Figure 1 is
T ₄ is made non-conducting for a short time and circuit 7 is connected to its output line d
The pulse output p ₁ ' shown in 3 is produced. This output
Due to P ₁ ', the NOT gate is activated in the recovery signal generation circuit 8.
The output of _N1 becomes L, and the charge of capacitor _C3 is
is discharged through N ₁ , but before the voltage on C ₃ makes the output of NOT gate N ₂ high, the output P ₁ ' disappears,
Since the output of N ₁ goes high again and C ₃ is recharged, N ₂ maintains the low output as shown in 4. Also, the output P ₁ ' of the circuit 7 sets the latch Lt ₂ formed by the NOR gates NR ₃ and NR ₄ of the timer circuit 9 , and the H output of NR ₄ causes the capacitor C ₄ to be connected through the resistor r ₁₃ as shown by the broken line at 5. When the voltage reaches H level, a clock signal is input to the CP terminals of monostable multi MM ₁ and MM ₂ .
The Q terminals of MM ₁ and MM ₂ have 6 and 6 H outputs, respectively.
As shown in 7, an L output is generated at the terminal of MM ₁ , the output of AND gate A ₂ becomes H as shown in 8, and the output of transistor T ₁ of the operation reference level switching circuit 10 also becomes _H. The reference level of the comparator CM of the comparator 3 becomes the lower limit value L ₁ of the normal level range determined by the resistance division ratio of the resistors r ₁ and r ₂ as shown by the broken line 11. Furthermore, since the Q output of MM ₂ is applied, the output of the NOT gate N ₂ of the fire discrimination section 4 becomes L and the operation of the gate A ₁ is prohibited, while the capacitor C ₅ of the function discrimination circuit 11 is charged. , when the voltage reaches the specified value, the output of gate N ₄ becomes L, but since the other input of gate NR ₅ is H, RH ₅ does not output a clock signal. In such a state, the light receiving amplifier of the light receiving section 2
When the AM pulse output is between the lower limit _L1 and the upper limit _L2 of the normal level range, as shown in 11, the pulse output is above the reference level of the comparator CM, so the CM is shown in 12. A detection pulse output is generated, and this pulse output is ANDed by the synchronization signal issued by the pulse oscillator PO ₁ and the H output of the NAD gate A ₂ .
Gate _A4 produces a pulse output similar to CM shown at 12. The function discrimination circuit 11 uses the output of _A4 .
The Q output of circuit FF ₁ is set to H as shown in 14, but circuit FF ₂ has a NOR gate at the CP terminal.
Since no clock signal is received from _NR5 , its Q output remains low as shown at 15. Then, after a short predetermined period of time has elapsed, the monostable multi-MM ₁ of the timer circuit 9 has its Q output set to L and its Q output set to H, as shown in 6. As a result, the output of AND gate _A2 becomes L as shown in 8, and circuit 1
The operation of the AND gate A ₄ of the circuit 10 is prohibited, and the transistor T ₁ of the circuit 10 is made non-conductive, while the output of the AND gate A ₃ becomes H as shown in 9, and the transistor T 2 becomes conductive, and the transistor T ₁ of the circuit 10 becomes non -conductive. The reference level of the comparator CM is the upper limit of the normal level range indicated by L2 at ₁₁ , which is determined by the division ratio of the resistance values of the resistors _r1 and _r2 + _r3 . In this state, the light receiving amplifier AM of the light receiving section 2
When a normal light receiving output is produced as shown in 11, the light receiving output is below the level _L2 , so the output of the comparator CM is L as shown in 12. When the output of the monostable multi-MM ₂ becomes L as shown in 7 after a long predetermined time has elapsed, the NOR gate NR ₅ is activated as shown in 16 by the L output and the L output of the NOT gate N ₄ in the function discrimination circuit 11 . A clock signal c is outputted as shown in FIG. 1. Due to this signal c, the Q output of the circuit FF ₂ becomes H as shown in 15 since the Q output of FF ₁ is H as shown in 14.
This H output of FF ₂ causes the signal generation circuit 5 to
The NAND gate NA ₁ produces a pulse output with a repetition rate f ₁ that is opposite in phase to the pulse output generated by the oscillator PO ₂ ,
NAND gate NA ₂ produces a repetition rate f ₁ pulse output shown at 20. In addition, the latch formed by NOR gates NR ₄ and NR ₇ is activated by the clock signal of NR _6.
Lt ₃ is set and the output of NR ₇ becomes H, which causes the output of the NOR gate NR ₈ of the transmitting circuit 6 to become L, and the NOR gate NR ₉ generates a pulse output with a repetition rate f ₁ shown in 21. , this output controls the conduction of the transistor T ₃ and sends the normal signal shown in 2 to the lines l ₁ and l ₂ . Finally, the receiving circuit 7 receives the restoration signal P ₂ shown in 2 from the receiver, and outputs the signal shown in 3 on its output line d.
When P ₂ ' occurs, the NOT gate N ₂ of the recovery signal generation 8 generates the clear signal c of 4, similar to the recovery operation at the time of a fire.
This signal c causes the NOR gate NR ₃ ,
The latches Lt ₂ and Lt ₃ formed by NR ₄ or NR ₆ and NR ₇ are reset, and the outputs of NR ₄ and NR ₇ become L as shown in 5 and 17, and the L of NR ₇ becomes L.
As a result of the output, the NOR gate ₉ no longer produces a pulse output as shown at 21, and the transmitting circuit 6 stops sending out the normal signal as shown at 2. In addition, the circuit in the function discrimination circuit 11 is activated by the clear signal of _N2 .
FF ₁ directly resets the circuit FF ₂ through the OR gate R ₁ , and the Q outputs of both circuits become L as shown in 14 and 15, and the L output of FF ₂ causes the output of the NAND gate NA ₁ of the signal generation circuit 5 to be reset. becomes H,
NA ₂ outputs a pulse signal with a repetition rate f ₂ as shown at 20, and the state of each part of the sensor returns to its original state. Next, because the light receiving surface of the light receiving element SB in the light receiving section 2 becomes contaminated with dust, the output of the light receiving output amplifier AM drops to the lower limit L ₁ of the normal level range.
The operation of each part during the test in the following cases will be explained with reference to the time chart shown in FIG. 5A. In this case as well, the receiving circuit 7 in FIG. 1 produces an output P ₁ ' on the output line d due to the test start signal P ₁ from the receiver shown _in 2 in FIG. The NOT gate _N2 of the recovery signal generation circuit 8 does not output a clear signal. On the other hand, P ₁ ' causes the timer circuit 9 to
Latch Lt ₂ formed by NOR gates NR ₂ and NR ₄
is set as shown in 5, and capacitor C ₄ is charged by the H output of NR ₄ as shown by the broken line in 5 through resistor r ₁₃ , and when it reaches the H level, the Q terminals of monostable multi MM ₁ and MM ₂ are connected. The H output is 6,7
The output of the AND gate _A2 becomes H, the transistor _T1 of the operation reference level switching circuit 10 becomes conductive as shown in 8, and the reference level of the comparator CM of the comparator 3 becomes 11 as shown by the broken line. As shown, the lower limit value L ₁ of the normal level range is reached. Also MM ₂ H
As a result of the output, the output of the NOT gate _N3 of the fire discrimination section 4 becomes L and prohibits the operation of the AND gate _A1 , while the NOR gate _NR5 of the function discrimination circuit 11 becomes 1.
No clock signal is output as shown in 6. In such a state, the amplifier AM of the light receiving section 2
When the received light output is below the level _L1 as shown at 11, the transistor _T1 of the operation reference level switching circuit 10 becomes conductive as shown at 8, and the reference level of the comparator CM of the comparator 3 becomes low. As shown in 11, even if it becomes L ₁ , the CM does not output a detection output as shown in 12, and the AND gate A ₄ of the function discrimination circuit 11
has no output and circuit FF ₁ is not set as shown at 14. Then, after a predetermined period of time has elapsed, the Q output of the monostable multi-MM ₁ of the timer circuit 9 becomes L and the output becomes H, as shown in 6, and the outputs of AND gates A ₂ and A ₃ become 8 and 9.
As shown in 11, each becomes L and becomes H, transistor T ₁ stops conducting, T ₂ becomes conductive, and even if the operating reference level of comparator CM becomes L ₂ as shown in 11, CM has 12 As shown in , there is no output and AND gate A ₅ produces no output. Further, after a predetermined period of time has elapsed, the Q output of the monostable multi MM ₂ becomes L as shown in 7, and the NOR gate NR ₅ of the circuit 11 outputs the clock signal c shown in 16.
Latch Lt ₃ is set and NOR gate NR ₇ is set to 17
The NOR gate of transmitter circuit 6 generates the H output shown in
When the output of _R8 becomes L, the signal generation circuit 5
NAND gate NA ₂ has a repetition rate f ₂ as shown in 20
Since it outputs a pulse signal of f 2, NR ₉ generates a pulse output of f ₂ as shown in 21, and the transistor
It controls the conduction of T ₃ and sends an abnormal signal to the receiver through lines l ₁ and l ₂ as shown in 2. Next , we will explain the operation of each part during the test when the output of the output amplifier AM of the light-receiving element SB in the light-receiving section ₂ exceeds the upper limit L2 of the normal level range due to dust accumulation in the dark box. This will be explained using the time chart shown in FIG. 6A. In this case, as in the previous case, in response to the test start signal P ₁ from the receiver shown in 2 in FIG. 6A, the receiving circuit 7 in FIG. 1 produces an output P ₁ ' shown in 3 on the output line d, The NOT gate _N2 of the recovery signal generation circuit 8 does not output a clear signal, but the latch _Lt2 of the timer circuit 9
is set, and the H output of the NOR gate _NR4 fills the capacitor _C4 to 5 as shown by the broken line.
When the level is reached, H output is generated at the Q terminals of monostable multi MM ₁ and MM ₂ as shown in 6 and 7,
The output of the AND gate _A2 becomes H, the transistor _T1 of the operating reference level switching circuit 10 becomes conductive as shown at 8, and the operating reference level of the comparator CM of the comparator 3 becomes the normal level as shown by the broken line at 11. The lower limit value of the range is _L1 . Furthermore, due to the H output of the Q terminal of MM ₂ , the output of the NOT gate _N3 of the fire discriminating section 4 becomes L, prohibiting the operation of the AND gate _A1 , while the NOR gate _NR5 of the function discriminating circuit 11 receives the clock signal. Not issued. In such a state, if the output of the amplifier AM in the light receiving section 2 exceeds _L2 as shown at 11, the transistor _T1 of the operation reference level switching circuit 10 becomes conductive as shown at 8, and the comparison section The operating reference level of comparator CM in No. 3 is as shown in No. 11.
When L becomes ₁ , the output of CM becomes H, and this output causes the output of AND gate _A4 of the function discrimination circuit 11 to become H.
As a result, the Q output of circuit FF ₁ is set to H as shown in 14, but since the clock signal from NOR gate NR ₅ does not enter the CP terminal of FF ₂ , FF ₂
The Q output of remains at L. After a predetermined period of time has elapsed in this state, the monostable multi-function of the timer circuit 9
The Q output of MM ₁ is L as shown in 6, and the output is H
As shown in 8 and 9, the outputs of AND gates A ₂ and A ₃ become L and H, respectively, transistor T ₁ stops conducting, T ₂ becomes conductive, and the operating reference level of CM becomes 11. As shown in the figure, even when switching to L ₂ , the CM output is H, and this output causes
AND gate _A5 and OR gate _R1 successively generate H outputs, which enter the reset terminal R of _FF1 , so
The Q output of FF ₁ is reset to L as shown at 14. Thereafter, even if an output is generated in CM, as long as the operating reference level of CM is _L2 , the Q output of FF ₁ will maintain L as shown in 14. It means that the output of CM is A ₅ and
This is because it enters the R terminal of FF ₁ through R ₁ . Then, as in the previous case, after a predetermined period of time has passed, the Q output of the monostable multi-MM ₂ becomes L as shown in 7.
When the NOR gate _NR5 of circuit 11 outputs the clock signal c shown in 16, the latch _Lt3 is set.
When the NOR gate NR ₇ produces the H output shown in 17 and the output of the NOR gate NR ₈ of the transmitting circuit 6 becomes L,
Since the NAND gate NA ₂ of circuit 5 is outputting a pulse signal with a repetition rate f ₂ as shown in 20, NR ₉ produces a pulse output of f ₂ as shown in 21 to control the conduction of transistor T _3. As shown in Figure 2, the line l ₁ ,
l Sends an abnormal signal to the receiver through ₂ . Therefore, if the output of the received light output amplifier AM falls below the lower limit L ₁ of the normal level range, and the upper limit
After the test when L ₂ or more, in FIGS. 5A and 6A, the operation when the receiving circuit 7 of the sensor receives the recovery signal P ₂ shown in 2 from the receiver will be explained. , the circuit 7 produces an output P ₂ ' shown in 3 on its output line d, and the NOT of the recovery signal generating circuit 8
Gate N ₂ outputs a clear signal c shown in 4, and this signal causes NOR gate NR ₃ , NR ₄ or
The latches Lt ₂ and Lt ₃ formed by NH ₆ and NR ₇ are reset, and the outputs of NR ₄ and NR ₇ become L as shown in 5 and 17, and the L output of NR ₇ causes
The NOR gate NR ₉ no longer produces a pulse output as shown in 21, the transmitter circuit 6 stops sending abnormal signals to the lines l ₁ and l ₂ as shown in 2, and the status of each part of the sensor is changed. Return to original condition. Finally, the operation of the receiver when a test is performed using the test start signal from the receiver shown in FIG. 2 will be explained. First _{, when switch} SW ₁ is closed for testing, relay Contact n ₁ closes and normal indicator light
When L _a3 lights up and an abnormal signal is received, relay M operates, contacts m ₁ and m ₂ close, and abnormal indicator lamp L _a2 lights up, indicating that an abnormality has occurred in the smoke detection function. Then, when switch SW ₂ is closed to restore the operation of the sensor, relay Y operates to close contact y ₁ and open contact y ₂ , operating the restoration signal generator RS and transmitting the restoration signal to line l ₁ , l ₂ , _{stops the operation of relay} and close _x4 to return to normal monitoring status. FIG. 7 is a circuit diagram of another embodiment of the present invention relating to a transmitted light type smoke detector that detects smoke using transmitted light, and the circuit diagram of a receiver corresponding to this embodiment is shown in the second embodiment.
It is similar to the figure. Compared to Figure 1, Figure 7 shows the upper limit L ₁ of the normal level range, which is the limit value at which transmitted light type smoke detectors are more likely to cause false alarms or delayed alarms.
and the lower limit value as the limit value that is likely to cause false alarms.
In order to determine the fire level L ₂ and the fire level L ₃ , the resistances r ₁ to _{r 4} connected in series between the conductors a and b are connected in the opposite order, and the resistances r ₁ and r The voltage at the connection point with ₂ goes to the + terminal of the comparator CM of the comparator 3 as the voltage at the operating reference level, and the output of the received light output amplifier AM of the light receiving part 2 goes to the - terminal, and the output of AM goes below the operating reference level. The only difference is that the CM generates a detection output when the voltage drops to . Therefore, the operational state of each part in the normal monitoring state and in the event of a fire in this embodiment is different from the time chart shown in FIG. 3A in the embodiment shown in FIG . 11 indicates the output of the comparator CM of the comparator 3 , and 12 indicates the output of the comparator CM of the comparator 3.
Therefore, only the different parts 11 and 12 are shown in the lower part of FIG. 3A as 11' and 12' in B. Next, the operation will be explained using the parts 11 and 12 in Fig. 3A and 11' and 12' in Fig. 3B.
Only the gist of the points already explained regarding Figure A will be described. In other words, in a normal monitoring state without smoke, the transistor _T1 of the receiving circuit 7 is conductive and there is no output on its output line d as shown at the left end of 3, and as a result, the output of the recovery signal generating circuit 8 is also , the outputs of the AND gates A ₂ and A ₃ of the timer circuit 9 are also L, the transistors T ₁ and T ₂ of the operation reference level switching circuit 10 are also not conductive, and the operation reference level of the comparator CM of the comparator 3 is at the fire level. L ₃ (for example, the output of the received light output amplifier AM, which indicates the amount of transmitted light when there is no smoke)
85% of the amount of transmitted light), so when AM generates a received light output pulse of L ₃ or more shown in 11', CM
In the L output state shown at 12', the output of A ₁ is L, and as a result, no signal is output to the lines l ₁ and l ₂ . However, the smoke from the fire causes the light-emitting element of light-emitting section 1 to
It enters between the LE and the light receiving element SB of the light receiving section 2 .
When the AM outputs a received light output pulse below the fire level as shown at 11', the CM is in the H output state as shown at 12', and the AND of the fire detection section 4
Gate _A1 uses the H output of this CM, the synchronization signal issued by oscillator _Po1 , and the H output of NOT gate _N3 .
A pulse output corresponding to the output of CM is generated, a latch Lt ₁ formed by NOR gates NR ₁ and NR ₂ is set as shown in 13, and the H output of NR ₂ is connected to the lines l ₁ and l through the transmitting circuit 6 . _2. Issue a fire signal with a repetition rate of f ₂ as shown in 2. The operation of the receiver that receives this fire signal and the recovery operation of the sensor based on the recovery signal from the receiver are the same as in the case of a scattered light type smoke detector. Next, the amplifier AM in the light receiving section 2 of this embodiment
The operational status of each part during the test when the output of 11 showing the output of amplifier AM
Since there is only a difference between 11 and 12 indicating the output of the comparator CM of the comparator 3 , only the different 11 and 12 are shown in the lower part of FIG.
1' and 12'. Therefore, the outline of the operation will be explained using the portions 11 and 12 in FIG. 4A and 11' and 12' in B. Test start signal shown in 2 sent from the receiver
Upon arrival of P ₁ , the receiving circuit 7 generates a pulse output P ₁ ' shown in 3 on its output line d, but since the pulse width is narrow, the recovery signal generating circuit 8 does not output a clear signal. Also, the timer circuit 9 is activated by the pulse P ₁ '.
The latch Lt ₂ is set by NOR gates NR ₃ and NR ₄ , and the H output of NR ₄ shown in 5 causes the capacitor to close.
When C ₄ is charged as shown by the broken line in 5 and reaches the H level, a clock signal is input to the CP terminals of monostable multi MM ₁ and MM ₂ , and the Q terminal of MM ₁ and MM ₂ as shown in 6 and 7. An H output is generated as _shown in _FIG . The level is at the upper limit L ₁ of the normal level range (for example, 105% of the amount of transmitted light), as shown by the broken line at 11'.
In this state, when the pulse output of the amplifier AM of the light receiving section 2 is between the upper limit value _L1 and the lower limit value _L2 of the normal level range as shown in 11', the pulse output is at the operating reference level of the comparator CM. Since the following, CM
is in the H output state as shown at 12' without producing an L output, and due to this H output, the synchronization signal issued by the pulse oscillator PO ₁ , and the H output of the AND gate A ₂ ,
A ₄ produces a pulse output similar to the pulse output shown in 12, and this pulse output causes the function discrimination circuit 11
The Q output of circuit FF ₁ is set to H as shown in 14, but since the clock signal from NOR gate NR ₅ is not input to the CP terminal of FF ₂ , its Q output is set to L as shown in 15. It remains as it is. Next, after a predetermined period of time has elapsed, the Q of the monostable multi-MM ₁ of the timer circuit 9 is
When the output becomes L as shown in 6 and the output becomes H, the output of AND gate A ₂ becomes L and the output of A ₃ becomes H as shown in 8 and 9, and the operation reference level switching circuit 10 Transistor T ₁ stops conducting,
T ₂ becomes conductive, and the operating reference level of the comparator CM of the comparator 3 becomes the lower limit value L ₂ of the normal level range. In this state, when the amplifier AM of the light receiving section 2 generates the normal light receiving output shown at 11', the light receiving output will be at the level
Since L ₂ or more, the output of the comparator CM becomes L as shown at 12'. Next, after a predetermined period of time has elapsed, when the output of the monostable multi-MM ₂ of the timer circuit 9 becomes L as shown in 7, the L output and the function discrimination circuit 1
By the L output of NOT gate N ₄ at 1
The NOR gate NR ₅ generates a clock signal c as shown at 16, and this signal c causes the circuit FF ₂ to generate the H output shown at 15 from the Q terminal, and the latch L _t3 set by the H output and the clock signal c. No. 1
With the H output of the NOR gate NR ₇ shown in 7, the line l ₁ ,
l Sends the normal signal shown in ₂ to 2. When the receiving circuit 7 receives the restoration signal _P2 shown in 2 from the receiver, the state of each part of the sensor is restored to its original state in the same manner as in the case of the scattered light type. Next, due to the influence of external light, the light receiving element of the light receiving section 2
The operating state of each part during the test when the output of SB increases and the received light output of amplifier AM exceeds the upper limit _L1 of the normal level range is also shown in Figure 5A of the embodiment shown in Figure 1. Compared to the time chart of
11 indicating the output of the light receiving output amplifier AM and the comparison section 3
12 which shows the output of the comparator CM of
Only these are shown as 11' and 12' in B at the bottom of FIG. 5A. Therefore, the operation will be explained using parts other than 11 and 12 in FIG. 5A and 11' and 12' in B.
Upon arrival of the test start signal P ₁ shown in 2, the receiving circuit 7 generates a pulse output P ₁ ' shown in 3 on its output line d in exactly the same way as in the previous case, but since the pulse width is narrow, the recovery signal cannot be generated. Circuit 8 does not output a clear signal, and the NOR gate NOR ₃ of timer circuit 9
The latch L _t2 by NOR ₄ is set, and the H output of NR ₄ as shown in 5 causes the monostable multi MM ₁ ,
The Q terminal of MM ₂ generates the H output shown in 6 and 7,
The output of the AND gate _A2 becomes H, the transistor _T1 of the operating reference level switching circuit 10 becomes conductive as shown at 8, and the operating reference level of the comparator CM of the comparator 3 becomes normal as shown by the broken line at 11'. The upper limit of the level range is _L1 . In this state, the light receiving output of the amplifier AM of the light receiving section 2 reaches the level L ₁ as shown at 11'.
If this is the case, the comparator CM of the comparator 3 has no output as shown at 12', and the transistors T ₁ and T ₂ of the circuit 10 switch to conduction as shown at 8 and 9, and the CM As shown in 11', even when the operating reference level changes from L ₁ to L ₂ , there is no output to CM,
After a certain period of time, the Q output of monostable multi MM ₂ becomes 7.
As shown in , the NOR gate _NR5 of the circuit 11 outputs the clock signal c shown in 16.
When NR ₇ produces an H output as shown at 17 and the output of the NOR gate ₈ of the transmitter circuit 6 becomes L, NR ₉ produces a pulse output with a repetition rate f ₂ as shown at 21, and the line l ₁ , l ₂ as shown in 2. Next, when the output of the received light output amplifier AM falls below the lower limit _L2 of the normal level range due to the light receiving surface of the light receiving element SB of the light receiving section 2 being contaminated with dust, etc. The operating states of the parts are also different from the time chart of FIG. 6A of the embodiment shown in FIG. Because there is a difference 1
1 and 12 at the bottom of Figure 6 A and 11' and 1 of B.
2'. Therefore , the operation will be explained by referring to the portions 11 and ₁₂ in FIG. A narrow pulse output P ₁ ′ shown in 3 is generated on the line d, the recovery signal generation circuit 8 does not output a clear signal, and the NOR gate NR ₃ of the timer circuit 9
The latch L _t2 by NR ₄ is set, and the H output of NR ₄ causes the monostable multi MM ₁ ,
The Q terminal of MM ₂ generates the H output shown in 6 and 7,
The output of the AND gate _A2 becomes H, the transistor _T1 of the operating reference level switching circuit 10 becomes conductive as shown at 8, and the operating reference level of the comparator CM of the comparator 3 becomes normal as shown by the broken line at 11'. The upper limit of the level range is _L1 . At this time, if the pulse output of the light receiving output amplifier AM of the light receiving section 2 is below the lower limit value _L2 of the normal level range, the comparator CM does not produce an L output and is in the H output state as shown at 12'. ,
This H output causes the AND gate _A4 of the function discrimination circuit 11 to generate a pulse output similar to the pulse output shown at 12, and this output sets the Q output of the circuit _FF1 to H as shown at 14. FF ₂
Since no clock signal is input to the CP terminal, FF ₂
The Q output of remains at L. In this state, transistor T ₂ eventually becomes conductive instead of T ₁ as shown in 9, and the operating reference level of CM switches to L ₂ as shown in 11', but at this time too, the output of CM is H. , This H output causes AND gate A ₅ and OR gate R ₁ to successively generate H output, which is input to the R terminal of FF ₁ , so that the Q output of FF ₁ becomes L as shown in 14. After a predetermined time has elapsed, the Q output of the monostable multi-MM ₂ becomes L as shown in 7, and the circuit 11
When the NOR gate NR ₅ outputs the clock signal c as shown in 16, the latch L _t3 by the NOR gates NR ₆ and NR ₇ is set, and NR ₇ produces an H output as shown in 17. In exactly the same manner as described in connection with FIG. 6A, an abnormality signal is sent to the receiver through the transmitting circuit 6 and lines l ₁ and l ₂ . When the output of the received light output amplifier AM exceeds the upper limit L ₁ of the normal level range and the lower limit
The operation of the sensor when the receiving circuit 7 of the sensor receives the recovery signal P ₂ from the receiver after the test when the voltage becomes L ₂ or less is also tested based on the test start signal from the receiver. The operation of the receiver in the case of a smoke detector is the same as in the case of a scattered light smoke detector. Furthermore, in the case of both scattered light and transmitted light smoke detectors, the sensor circuitry may fail or the line
Even after the test start signal is sent from the receiver shown in Figure 2 when l ₁ and l ₂ are disconnected, neither normal nor abnormal signals from the sensor reach the receiver, even if the operating time of timer T has elapsed. If not, the timer T operates and closes the contact t, so that the fault indicator light _L4 lights up, and it is possible to know that there is a fault in the sensor circuit or the lines _l1 and _l2 . In the above embodiment, the smoke detector and the receiver are connected by two lines that serve as a power supply line and a signal line. For example, in FIGS. 1 and 7, a constant voltage circuit Separate the power line and signal line by disconnecting the right terminal of the CV from the line _l1 and connecting it to the third line _l3 dedicated to the power supply, thereby eliminating the influence of the signal amplitude on the constant voltage circuit CV. Alternatively, the S/N ratio may be increased. Since this invention is provided with a timer circuit and an operating reference level switching circuit, the operating reference level of one comparator in the comparing section is normally maintained at the fire level, and during a functional test, the operating reference level of one comparator is maintained at the fire level. Each limit value is switched sequentially. Therefore, in addition to detecting a fire, the output of the comparator can be used to perform a sensitivity test to determine whether the sensitivity of the sensor itself is within the normal level range. In addition, since a receiving circuit, a signal generating circuit, and a transmitting circuit are provided, when a test start signal is received from the receiver, a sensitivity test is performed, and the result is sent as a normal or abnormal signal from the transmitting circuit to the receiver. be done.
Therefore, simply by transmitting a test start signal, it is possible to automatically know whether the sensitivity of the sensor itself is within the normal level range. More specifically, based on the signal sent from the receiver through the line connecting the smoke detector and the receiver, the light output at the smoke detector is automatically adjusted to a normal level range that does not cause false alarms, missed alarms, or delayed alarms. It has the excellent effect of easily and accurately testing the presence or absence of an important function for a photoelectric smoke detector, such as whether or not it is present inside the sensor, and reporting the results to the receiver through the same line. be.

[Brief explanation of drawings]

1 and 7 are circuit diagrams of respective embodiments of a scattered light type smoke detector and a transmitted light type smoke detector equipped with a smoke detection function test device according to the present invention, and FIG. 2 is a circuit diagram common to these two embodiments. The circuit diagrams of the receiver, FIGS. 3 to 6, are time charts showing the operating states of each part in various cases of the embodiments of FIGS. 1 and 7.
Figure 3A shows the embodiment shown in Figure 1 in normal conditions and in the event of a fire.
Figure 4A shows the results of Figures 5A and 6 during the test when the received light output of the embodiment shown in Figure 1 is within the normal level range.
Figure A is the test result when the received light output of the embodiment shown in Figure 1 is below the lower limit of the normal level range and when it is above the upper limit.
In the time charts corresponding to FIGS. 3A to 6A of the illustrated embodiment, 1 shows the output of the light receiving output amplifier AM different from that of FIGS. 3A to 6A.
Only 1' and 12' indicating the output of the comparator CM are shown. 1 ... Light emitting section, 2 ... Light receiving section, 3 ... Comparing section,
4...Fire discrimination section, 5 ...Signal generation circuit, 6 ...
Transmission circuit, 7 ...Reception circuit, 8 ...Recovery signal generation circuit, 9 ...Timer circuit, 10 ...Operation reference level switching circuit, 11 ...Smoke detection function determination circuit.

Claims (1)

[Claims] 1. A timer circuit that outputs a switching signal when the receiving circuit receives a test start signal; the operating reference level is normally held at the fire level, and the switching signal of the timer circuit sets each limit value level above and below the normal level range. an operating reference level switching circuit that sequentially switches to the operating reference level; a comparing section that is composed of one comparator and that compares the received light output of the light receiving section and the operating reference level;
a fire discrimination unit that maintains a fire output based on the output from the comparison unit at the fire level; determines whether or not the level is within the normal level range based on the output from the comparison unit at each of the limit value levels, and outputs the result for discrimination; a signal generation circuit that generates a fire signal based on the fire output and also generates a normal or abnormal signal based on the discrimination output;
A photoelectric smoke detector equipped with a smoke detection function testing device, characterized in that it comprises: a transmitting circuit for transmitting an output signal of the signal generating circuit to a receiver.