JP3256431B2 - Unit fire alarm - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fire alarm system for a dwelling unit, and more particularly to a fire alarm system for a dwelling unit which can reliably issue a fire alarm irrespective of the ratio between the current at the time of fire and the current at the time of monitoring.

[0002]

2. Description of the Related Art Conventionally, a dwelling unit fire alarm device shown in FIG. 3 has been proposed. The dwelling fire alarm system, sensor terminal resistor R ₂₀ is a plurality of fire detectors S provided at the end
E ₁₁ , SE ₁₂ , an interface IF ₁₁ , an alarm sound circuit 51, an alarm display device 52, a receiver CPU 53, an alarm indicator LED _11, and a receiver EQ ₃ provided with an acoustic device SP ₁₁ , and a fire detector SE ₁₁ , SE ₁₂ are connected to sensing terminals T ₁₁ , T ₁₁ of the receiver EQ ₃ via sensing lines L ₁₁ , L _12.
Connected to ₁₂ respectively.

[0003] The interface IF ₁₁ of the receiver EQ ₃ is a detection unit K ₁₁ provided with a transistor Q ₁₁ and resistors R ₂₁ and R _22.
When having a transistor Q _12, resistors R _23, detector K ₁₂ having a R _24, diode D _11, resistor R _25, a resistor R _26,
Sensing terminal T ₁₁ is connected the cathode of the diode D _11, an input pin P ₁₂ of the receiver CPU53 through the anode.

The sensing terminal T ₁₁ is connected to a resistor R of the detecting section K ₁₁ .
₂₂ through the connected to the base of the transistor Q _11, the base and emitter of the transistor Q ₁₁ is connected by a resistor R _21. The emitter of the transistor Q ₁₁ is connected to the power supply + B, collector receiver CP which the detection signal f ₁₂ is input
It is connected to the input pin P ₁₂ of U53.

[0005] resistance of the sensing terminal T ₁₁ is detecting section K ₁₂ R
Is connected to the base of the transistor Q ₁₂ through _24, the base and emitter of the transistor Q ₁₂ is connected by a resistor R _23. The emitter of the transistor Q ₁₂ is connected to the power supply + B, collector detection signal f ₁₁ is a receiver CP input
It is connected to the input pin P ₁₁ of U53.

[0006] The collector of the transistor Q ₁₁ is connected through a resistor R _25, the collector of the transistor Q ₁₂ is respectively a reference potential point of the sensing terminal T ₁₂ is connected via the resistor R ₂₆ connected. Alarm sound output pin P _{14 of} receiver CPU 53
Is connected to the audio device SP ₁₁ via the alarm sound circuit 51,
Alarm display output pins P ₁₃ is connected through a resistor R ₂₇ which is provided on the alarm display device 52 and the base of the transistor Q _13, the base and emitter of the transistor Q ₁₃ is connected by a resistor R _28. The emitter of the transistor Q ₁₃ is connected to a reference potential point, and the collector is connected to the via to the power supply + B cathode alarm indicator LED ₁₁ to a light emitting diode, the anode.

In such a dwelling unit fire alarm device, for example, the fire detectors SE ₁₁ and SE ₁₂ are connected to a P-type Class 3 receiver for fire or a receiver EQ ₃ which is a GP-type Class 3 receiver for gas and fire. Connecting. Circuit disconnection (i.e. sensor terminal resistor R ₂₀ is disengaged, etc.) For the considered as disconnection state, the alarm sound output pins audio or alarm sound indicating the P ₁₄ is disconnected state of the receiver CPU53 "Phi ... ... "
Via blink at a slow cycle alarm indicator LED ₁₁ via the alarm display device 52 from the alarm display output pins P ₁₃ sends out the audio device SP _11.

If the fire detectors SE ₁₁ and SE ₁₂ are activated, a sound or warning sound indicating that a fire has occurred is displayed.
.... "The via an audible alarm circuit 51 to blink at short intervals an alarm indicator LED ₁₁ via the alarm display device 52 from the alarm display output pins P ₁₃ sends out the audio device SP _11. Here, the current flowing through the sensing lines L ₁₁ and L ₁₂ at the time of disconnection is referred to as a current i ₁₁ at the time of disconnection, and the sensing lines L ₁₁ and L ₁₂ at the time of monitoring.
The current flowing through the sensor is monitored i ₁₂ , and the sensing line L during a fire
_11, the current flowing through the L ₁₂ to fire when current i _13, if each is set to _{i 11 <1mA 2mA <i 12} <3.3mA 7mA <i 13 <50mA,
Sensor terminal resistor R ₂₀ is 4.7 kOhm, the resistor R ₂₁ is 90 ohms,
Resistor R ₂₂ is 180 ohms, the resistor R ₂₃ 100 K.OMEGA, resistor R ₂₄
Is 10 KΩ, the resistors R ₂₅ and R ₂₆ are each 47 KΩ, and the power supply + B is 12 V.

According to this condition, the base of the transistor Q ₁₂ when the disconnection current i ₁₁ flows through the sense line L _11, L _12, emitter operating voltage VBE ₁₂ is, RZ × [(R ₂₂ +
R ₂₁ ) × i ₁₁ ] <VBE ₁₂ . RZ is the resistance R
₂₃ (100 K in this case) divided by the resistance value (110 KΩ in this case) obtained by adding the resistance R ₂₄ and the resistance R ₂₃ .

Further, the monitoring current i ₁₂ is applied to the sensing lines L ₁₁ , L
When flowing to _12, based _{RZ × [(R 22 + R} 21) × i 12]> VBE 12 monitors when the transistor Q ₁₁ in the current i _12, the operating voltage VBE ₁₁ between emitter, R ₂₁ × i ₁₂ <VBE ₁₁ the base of the transistor Q ₁₁ in case of fire current i _13, the operating voltage VBE ₁₁ between the emitter becomes _{R 21 × i 13> VBE 11} .

[0011] In other words, the sensing line L from the sensing terminal T _11
11, the current flowing through the L ₁₂ is the transistor Q _11, Q ₁₂ are both turned off when the disconnection time of the current i _11, the detection signal f _11, f ₁₂ the voltage level of the input to the input pin P _11, P ₁₂ of CPU53 Is at the L level. Then the transistor Q ₁₁ when the sense lines L _11, L the current flowing through the ₁₂ is monitored during current i ₁₂ from the sensing terminal T ₁₁ is turned off, the voltage level of the detection signal f ₁₂ transistor Q ₁₂ is turned on is the L level It is as it is
The voltage level of the detection signal f ₁₁ becomes H level.

[0012] The next sensed from the sensing terminal T ₁₁ line L _11,
Transistor Q ₁₁ when the current fire during current i ₁₃ flowing through L _12, the transistor Q ₁₂ are both turned on, the voltage level of the detection signal f _12, f ₁₁ is both the H level, the receiver CPU53 input pin Based on the voltage levels of the detection signals f ₁₁ and f ₁₂ input to P ₁₁ and P ₁₂ , the disconnection, monitoring, and fire states are determined, and an alarm corresponding to each state is given by the sound device SP ₁₁ and the alarm indicator LED _11. Performed by

[0013]

THE INVENTION Problems to be Solved In such a dwelling unit fire alarm device, the size is monitored during current i ₁₂ fire when current i ₁₃
Based voltage drop transistor Q ₁₁ in the sensing terminal T ₁₁ when the about two to three times, emitter voltage VBE ₁
There is no problem because it is about two to three times larger than the above. However, if the fire current i ₁₃ becomes 10 times or more the monitoring current i ₁₂ depending on the type of the fire detectors SE ₁₁ and SE ₁₂ , the resistance R ₂₂ is reduced. Resistance R
₂₁ is required to be set to a very large resistance value compared to (e.g., a resistor R ₂₂ 1800Ω, the resistance R ₂₁ and 180 ohms).

[0014] sensing terminal T ₁₁ at the time of fire in a state set much larger than the resistor R ₂₂ in this manner the resistor R ₂₁
Voltage drop in the fire detector SE ₁₁ , SE
There was a disadvantage that the operation of ₁₂ could not be maintained. (In the above example, the fire current i ₁₃ is 3.4 mA or more, and the monitoring current i ₁₂ is 0.3 mA or less.) The present invention has been made to solve such a conventional difficulty. It is an object of the present invention to provide a dwelling unit fire alarm device that can surely issue a fire alarm regardless of the ratio of hourly current.

[0015]

In order to achieve the above object, a dwelling unit fire alarm device according to the present invention comprises a fire detector through which a current at the time of disconnection at the time of disconnection, a current at the time of monitoring at the time of monitoring, and a current at the time of fire at the time of fire, respectively. A sound device that sounds an alarm sound by an alarm sound circuit based on a fire current and a disconnection current, and a receiver that has an alarm indicator light that flashes an alarm display by an alarm display circuit. Disconnection current flowing through the sensing line connected by the sensing line,
It has an interface for detecting the monitoring current and the fire current respectively.
A detector consisting of a base resistor connected between the base and the emitter of the transistor and a Schottky diode connected between the base and the collector is vertically connected in a plurality of stages, and is turned on when a transistor in a stage preceding the last stage is turned on. A transistor that increases the emitter voltage of the transistor in the preceding stage by bypassing the transistor in the subsequent stage from the transistor in the preceding stage, connects the sensing line to the detection unit in the first stage, and extracts a detection signal from the detection unit in each stage. I have.

In such a fire alarm system for a dwelling unit, a current at the time of disconnection at the time of disconnection, a current at the time of monitoring at the time of monitoring, and a current at the time of fire at the time of fire flow to the receiver via the sensing line. When the disconnection current and the fire current flow to the receiver, the alarm sound circuit and the alarm display circuit provided in the receiver respectively operate, the alarm sounds from the sound device, and the alarm indicator of the alarm display device blinks. It has become.

The receiver is provided with an interface for such an alarm. The interface includes a transistor, a base resistor connected between the base and the emitter of the transistor, and a Schottky diode connected between the base and the collector. When a transistor at a stage preceding the last stage is turned on, a transistor at a stage subsequent to the turned-on transistor is bypassed, and a transistor for increasing the emitter voltage of the preceding stage transistor operates. .

When the transistor for increasing the emitter voltage of the preceding transistor operates, a detection signal is output from the detection section of each stage, and the detection signal is taken out and the above-mentioned alarm is issued.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the fire alarm system for dwelling units according to the present invention will be described in detail with reference to FIG. As shown in FIG. 1, the dwelling unit fire alarm device according to the present invention has a disconnection current i ₁ at the time of disconnection, a monitoring current i ₂ at the time of monitoring, and a fire current i at the time of fire.
₃ is a fire detector SE _1, SE ₂ flowing respectively, of fire current i _3, audio device SP ₁ and alarm display sounding an alarm sound by the alarm sound circuit 1 based on the disconnection current i ₁ circuit 2
And a receiver EQ ₁ with an alarm indicator LED ₁ flashing the alarm display by the receiver disconnection when current i ₁ which is connected by a sensing line L _1, L ₂ from the fire detector through the sensing line, during the monitoring current i _2, and an interface IF ₁ for detecting a fire when current i ₃ respectively, the interface IF _1, the transistor Q _1, and Q _2, the base of the transistor, base resistor R ₁ connected between the emitters, R
₂ and detectors K ₁ , K ₂ composed of Schottky diodes D ₁ , D ₂ connected between the base and the collector are vertically connected in a plurality of stages, and when a transistor Q ₂ in a stage preceding the last stage is turned on, the turned-on transistor Q ₂ from the rear stage of the transistor Q ₁ to bypass the transistor Q ₄ to raise the emitter voltage of the transistor Q ₂ of the preceding stage is provided, to connect the sense lines to the detection unit of the first stage, from the detection unit of each stage It is configured to extract the disconnection detection signal f ₂ and the operation detection signal f ₁ .

As shown in FIG. 1, the dwelling unit fire alarm device comprises:
A plurality of fire sensors SE ₁ and SE ₂ provided with a terminating resistor R ₀ at the end, an interface IF ₁ , an alarm sound circuit 1, an alarm display device 2, a receiver CPU 3, and an audio device SP.
Consists ₁ and an alarm indicator LED ₁ at the receiver EQ ₁ provided, fire detector SE _1, SE ₂ is sense lines L _1, the sensing terminal T ₁ of the receiver EQ ₁ through L _2, T ₂ When connected, respectively, the sensing terminal T ₂ is connected to a reference potential point.

The interface IF ₁ of the receiver EQ ₁ comprises a transistor Q ₁ , a resistor R ₁ and a Schottky diode D
₁ and the detection unit K ₁ provided with the transistors Q _2, resistors R ₂ and the Schottky diode and the detecting section K ₂ having a D _2, the upstream detection unit driving circuit Z ₁ and final stage comprising transistors Q ₄ and Q ₅ It has a reference potential point side resistor R _12, the sensing terminal T ₁ is connected to the base of the transistor Q ₂ to which is provided in the detection section K _2.

The base of the transistor Q ₂ is connected to the collector via the cathode and anode of the Schottky diode D ₂ , and the base is connected to the emitter via the resistor R ₂ . The collector of the transistor Q ₂ is connected to the input pin P ₁ receiver CPU3 the operation detection signal f ₁ is input.

The transistor collector of Q ₂ is connected via a base to a resistor R ₆ of the transistor Q ₅ provided on the upstream detection unit driving circuit Z _1, base and a reference potential emitter connected to the point of the transistor Q ₅ is It is connected via a resistor R _7. The emitter of the transistor Q ₂ is connected to the base of the transistor Q ₁ which is provided in the detection section K _1, the base of the transistor Q ₁ is connected to the collector via the cathode of the Schottky diode D _1, the anode.
The base of transistor Q ₁ is connected to the emitter via a resistor R _1, the collector is connected to the reference potential point through a final stage reference potential side resistor R _12.

The connection point of the collector of the transistor Q _1, the last stage reference potential side resistor R ₁₂ is connected to an input pin P ₂ receivers CPU3 the disconnection detection signal f ₂ is input, the emitter is connected to the power supply + B ing. Front-stage detector drive circuit Z
The emitter of the transistor Q ₄ provided in ₁ is connected to the power supply + B, and emitter connected to the base via a resistor R _4.

The collector of the transistor Q ₄ is connected to the transistor Q ₂ of the emitter provided on the detector K _2, the base of the transistor Q ₄ are connected to the collector of the transistor Q ₅ through a resistor R _5. The alarm sound output pin P ₄ of the receiver CPU 3 is connected to the sound device SP ₁ via the alarm sound circuit _1.
Is connected to an alarm display output pins P ₅ is connected to the base of the transistor Q ₈ through the resistor R ₁₃ provided in the alarm display device 2, the base and emitter of the transistor Q ₈ is connected by a resistor R ₁₄ . The emitter of the transistor Q ₈ is connected to a reference potential point, and the collector is connected to the via to the power supply + B alarm indicator cathode of LED _1, the anode and the resistor R ₁₅ to a light emitting diode.

In the dwelling unit fire alarm system shown in FIG. 1, for example, the fire detectors SE ₁ and SE ₂ receive a P-type Class 3 receiver for fire or a GP-type Class 3 receiver for gas or fire. via connecting machine EQ _1, the conventional similar operation is performed, the input pins P ₁ and actuation detection signal f ₁ is input to the P _2, the voltage level of the disconnection detection signal f _2, the alarm sound circuit 1 Then, the sound is displayed by the alarm indicator LED ₁ via the sound device SP ₁ and the alarm display device 2.

Here, when the fire detectors SE ₁ and SE ₂ are in the monitoring state, the current flowing through the sensing lines L ₁ and L ₂ is monitored by the monitoring current i ₂ and the sensing line L when the terminating resistor R ₀ is disconnected. _1, L ₂ the disconnection currents i ₁ the current flowing in the current flowing through the sensing line L _1, L ₂ when the fire detector SE _1, SE ₂ is operated to fire during current and i _3. At this time, the resistance R ₁ ,
R ₂ , R ₆ and R ₇ are set so as to satisfy the following conditions.

R ₁ × i ₁ <VBE ₁ R ₁ × i ₂ > VBE ₁ R ₂ × i ₂ <VBE ₂ R ₂ × i ₃ > VBE _{2 Further} , _VA is (12V−VBE ₁ −VCE ₂ ). , _VA × [R ₇ ÷ (R ₆ + R ₇ )]> V BE ₅ where [R ₇ ÷ (R ₆ + R ₇ )] is a voltage applied to the resistors R ₆ and R ₇ , and both ends of the resistor R ₇ generated voltage indicates that it is applied as a base bias of the transistor Q _5.

In this case, the resistance value of each resistor is R ₁
= 330Ω, R ₂ = 120Ω, R ₆ = 47 KΩ, R ₇ = 4.
7 KΩ and V _A means that if V CE ₂ is 1 V or less (when transistor Q ₂ operates), V _A becomes 10 V or more, and transistor Q ₅ is turned on. Further, the detector terminating resistance R ₀ = 4.7 KΩ, R ₄ = 3.3 KΩ, R ₅ = 3.
3 KΩ, and the final stage reference potential point side resistance R ₁₂ = 47 KΩ.

[0030] Incidentally, the power source + B is _{12V, VBE 1, VBE 2,} V
BE ₅ is the base of transistors Q ₁ , Q ₂ , Q ₅ , respectively.
Emitter operating voltage, VCE ₂ collector during operation of the transistor Q _2, an emitter voltage. Here, when disconnection of the like sensor terminal resistor R ₀ outside the detector K current outputted from the sensing terminal T ₁ of the receiver EQ ₁ to sense lines L _1, L ₂ becomes disconnected during current i ₁ Transistor Q provided in _1
1 and transistor Q ₂ to which is provided in the detection unit K ₂ are both turned off, the input pin P ₁ and the voltage level of the operation detecting signal f ₁ and the disconnection detection signal f ₂ inputted to the P ₂ receivers CPU3 is Both become L level.

Next, during monitoring, the current output from the sensing terminal T ₁ of the receiver EQ ₁ is the monitoring current i ₂ , and the detection unit K
A voltage of R ₁ × i ₂ is applied between the base and the emitter of the transistor Q ₁ provided in ₁ , and the transistor Q ₁ is turned on. At this time, when the transistor Q ₁ is completely turned on,
The collector of the transistor Q _1, emitter voltage VCE ₁ becomes about 0.1 V, since the voltage drop of the Schottky diode D ₁ is about 0.3V, the base of the transistor Q _1, emitter voltage VBE ₁ is about 0.4V And the transistor Q ₁
Turns off.

Therefore, the transistor Q ₁ is not completely turned on, and the Schottky diode D ₁ is operated so that the voltage VCE ₁ between the collector and the emitter operates in the active region of about 0.3 V.
Feedback. Transistor Q ₁ is a voltage develops across the last stage reference potential side resistor R ₁₂ when operating in the active region, the voltage level of the disconnection detection signal f ₂ inputted to the input pin P ₂ receivers CPU3 is the H level Become.

[0033] Although not be extracted so much current from the base of the transistor Q ₁ in this state, through the Schottky diode D _1, the collector current of the transistor Q ₁ is supplied, the voltage drop of the transistor Q ₁ base,
Emitter voltage VBE ₁ and monitoring during the current i ₂ is a voltage drop caused by the flowing through the resistor R ₂ (based on this circuit, emitter voltage VBE ₁ is determined by the collector current, 1V or less in general transistor Becomes).

Next, fire fire detector SE _1, SE ₂ the sensing line L ₁ from the sensing terminal T ₁ of the receiver EQ ₁ when operated, L ₂ to the current output by the fire when current i ₃ next detection transistor Q ₂ of the base parts K _2, the resistance between the emitter R ₂
, A voltage of R ₂ × i ₃ is applied to the transistor Q _2, and the transistor Q ₂ is turned on in the active region in the same manner as the transistor Q ₁ of the detection unit K ₁ during monitoring.

[0035] When the transistor Q ₂ is operated in the active region, the voltage level of the operation detecting signal f ₁ which is input to the input pin P ₁₂ of the receiver CPU3 has an H level. At this time, a voltage is applied to the resistors R ₆ and R ₇ of the preceding stage detection unit drive circuit Z ₁ ,
Base voltage transistor Q ₅ which occurs across the resistor R _7, because it is set to be larger than the emitter operating voltage VBE _5, the transistor Q ₅ is turned on.

[0036] In addition, it draws the base current of the transistor Q ₄ When the transistor Q ₅ is turned on, the transistor Q ₄
Also turns on at the same time. When the transistor Q ₄ is turned on, the emitter of the transistor Q _4, the collector voltage VCE ₄ 0.
Since a higher 1V, 12V from the transistor Q ₁ based power voltage collector voltage of the transistor Q _2, the collector emitter voltage VBE ₁ transistor Q ₄ than the voltage obtained by subtracting (0.7 V as) from the supply voltage 12V, The voltage is raised to a value obtained by subtracting the emitter voltage VCE ₄ (about 0.1 V).

This has the function of suppressing the voltage drop between the sensing terminals T ₁ and T ₂ . By the way, the transistor Q ₄
There is turned on, the base of the transistor Q _1, since emitter voltage VBE ₁ is about 0.1 V, the transistor Q ₁
Turns off. That is, the transistors Q ₁ and Q ₂ are not turned on at the same time. Above, output input pin disconnection detection signal f ₂ to P ₂ receivers CPU3 provided receiver EQ ₁ and transistor Q ₁ is turned on is, it can be seen that not disconnected. The operation detection signal f ₁ to an input pin P ₁ receiver CPU3 the transistor Q ₂ is turned on is outputted,
It can be seen that the fire detectors SE ₁ and SE ₂ have operated.

Here, the disconnection current i ₁ , the monitoring current i ₂ ,
The fire current i ₃ is i ₁ <1 mA ₂ mA <i ₂ <3.3 mA 6 mA <i ₃ <50 mA. The transistor may be a general low power PNP transistor, and the diode may be a Schottky diode.

FIG. 2 shows an example in which the function of the sensor is increased, three states of disconnection, monitoring and operation are detected, and a three-stage detection unit is provided to detect four or more states. The receiver EQ ₂ shown in FIG. 2 has an interface I in which detector driving circuits Z ₁ and Z ₂ are inserted between detectors K ₁ , K ₂ and K ₃ , respectively.
It has a F _2. Detector K ₃ of interface IF ₂
The emitter of the transistor Q ₃ which is provided is connected to the base of the transistor Q ₂ of detector K ₂ disposed downstream, the collector of the transistor Q ₆ emitters provided on the detector drive circuit Z ₂ of the transistor Q ₃ Is connected to

The base is disconnected when current i ₁ of the transistor Q _3, monitored during current i _2, a fire flowing when fire during current i ₃ flows when the fire detector SE ₁ is operated, and the fire detector SE ₂ is operated The current i ₄ is connected to the sensing terminal T ₁ to be inputted, and the fire detectors SE ₁ and SE ₂ are connected.
The emitter of the transistor Q ₃ are connected to the base via a resistor R _3, the collector is connected to the base via the anode of the Schottky diode D _3, the cathode.

The collector of the transistor Q ₃ is the detection signal f ₃
It is connected to the input pin P ₃ of receiver CPU3 input a. The emitter of the transistor Q ₆ provided in the detecting section drive circuit Z ₂ is connected to the power supply + B, and emitter connected to the base via a resistor R _8. Transistor Q ₆
The base is connected to the collector of the transistor Q ₇ through a resistor R _9.

The reference potential point connected to the sensing terminal T ₂ is connected to the emitter of the transistor Q ₇ , and the emitter of the transistor Q ₇ is connected to the base via the resistor R ₁₁ . Based transistor Q ₇ is connected to the collector of the transistor Q ₃ provided in the detection portion K ₃ through the resistor R _10. Note that the resistors R _{8 to} R _{11 of} the detection unit driving circuit Z ₂
The resistance value is equal to the resistance of the resistor R ₄ to R ₇ of the detector drive circuit Z _1, the resistance value of the resistor R ₃ of the detecting unit K ₃ is detecting section K ₂
A resistor R ₂ and slightly modified example 46Ω approximately.

[0043] _{i 3 <i 4 R 3 ×} i 3 <VBE 3 R 3 × i 4> VBE 3 Further, V _C is the _{(12V-VBE 2 -VCE 4 -VCE} 3), V C × [R 11 ÷ based _{(R 10 + R 11)]} > VBE 7 wherein VBE _2, VBE ₇ each transistor Q _2, Q _7, emitter operating voltage, VCE _3, VCE ₄ the collector during operation of the transistor Q _3, Q ₄ , The voltage between the emitters.

[0044] omitted because this operation principle of the receiver EQ ₂ shown in FIG. 2 is the same as the receiver EQ ₁ shown in FIG.

[0045]

As is apparent from the above description, according to the present invention, a fire detector through which a current at the time of disconnection when a wire breaks, a current at the time of monitoring at the time of monitoring, and a current at the time of fire during a fire, respectively, An alarm device for sounding an alarm sound by an alarm sound circuit based on an hour current; and a receiver having an alarm indicator light for flashing an alarm display by an alarm display circuit, wherein the receiver is connected to the fire detector by a sensing line and sensed. It has an interface for detecting the current at disconnection, the current at monitoring, and the current at fire, respectively, flowing through the line.The interface is connected between the transistor, a base resistor connected between the base and emitter of the transistor, and between the base and collector. Detectors consisting of Schottky diodes are connected in multiple stages vertically. Since the transistor at the later stage than the transistor is bypassed, a transistor that raises the emitter voltage of the transistor at the previous stage is provided, the sensing line is connected to the detection unit at the first stage, and the detection signal is extracted from the detection unit at each stage, Fire alarms can be issued reliably regardless of the ratio of fire current and monitoring current.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a dwelling unit fire alarm device according to the present invention.

FIG. 2 is a block diagram showing another embodiment of a dwelling unit fire alarm device according to the present invention.

FIG. 3 is a block diagram of a conventional dwelling unit fire alarm device.

[Explanation of symbols]

1 ... alarm sound circuit 2 ... alarm display circuit SE ₁ , SE ₂ ... fire detector EQ ₁ ... receiver IF ₁ ... Interface SP ₁ Sound device LED ₁ Alarm indicator Q ₁ , Q ₂ , Q ₄ Transistor i ₁ Disconnection current i ₂ · · · · · · monitored during current i ₃ · · · · · · of fire current f ₁ · · · · · · actuation detection signal (detection signal) f ₂ · · · · · · disconnection detection signal (detection Signal) L ₁ , L ₂ ... Sensing line R ₁ , R ₂ ... Base resistance D ₁ , D ₂ ... Schottky diode K ₁ , K _2. ···Detection unit

──────────────────────────────────────────────────続 き Continuation of front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G08B 29/18 G08B 23/00 530 G08B 25/00 520 H04M 11/04

Claims (1)

(57) [Claims] 1. A disconnection during current during disconnection (i _1), and during the monitoring when the monitoring current (i _2), the fire detector flowing fire during current (i ₃₎ are each in a fire (SE _1, SE _2), wherein An acoustic device (SP ₁ ) that sounds an alarm sound by an alarm sound circuit (1) based on the fire current and the disconnection current, and an alarm indicator (LED) that flashes an alarm display by an alarm display circuit (2).
Comprising ₁₎ a receiver having a (EQ _1), the receiver is sense lines from the fire detector (L _1,
L ₂ ), and an interface (IF ₁ ) for detecting the disconnection current, the monitoring current, and the fire current flowing through the sensing line, respectively, wherein the interface comprises a transistor (Q ₁ , Q ₂ )
A detection unit (K ₁ ) comprising a base resistor (R ₁ , R ₂ ) connected between the base and the emitter of the transistor and a Schottky diode (D ₁ , D ₂ ) connected between the base and the collector , K ₂ ) are vertically connected in a plurality of stages, and when a transistor (Q ₂ ) at a stage preceding the last stage is turned on, a transistor (Q ₁ ) at a stage subsequent to the turned-on transistor is bypassed, and the emitter voltage of the transistor at the preceding stage is reduced. A dwelling unit fire alarm, characterized in that a rising transistor (Q ₄ ) is provided, the sensing line is connected to a first stage detection unit, and detection signals (f ₂ , f ₁ ) are taken out from each stage detection unit. apparatus.