JPH01201799A - Fire alarm system for residential units - Google Patents

Abstract

PURPOSE:To detect the disconnection of a sensor by detecting the presence or absence of a current flowing in the prescribed terminal of the sensor having plural terminals. CONSTITUTION:When the fire sensitive device 3 operates, a display element 22 in the fire sensitive device 311 depends on an oscillation period which is decided by an oscillation circuit 29 and repeats flicker. When the connection line of a thermal sensor 411 connected any one of the terminals P1-P4 is disconnected, the generation of a loop via the thermal sensor 411 is prevented, and a transistor 19 is turned off. A voltage is impressed on the display element 22 through a diode 25 and a resistance 23 and the display element 22 continuously flickers.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a fire alarm system for a dwelling unit that notifies a fire within the dwelling unit by the operation of a sensor installed within the dwelling unit.

Conventional fire alarm systems for residential units have a structure in which a heat sensor, a smoke detector, etc. detect a rise in temperature in the room to be notified, or smoke generation, etc., and issue a fire alarm based on this detection. There is. That is, in the case of a heat sensor, its operation level is set above the normally considered ambient temperature, and a fire is determined based on the operation of the heat sensor above this temperature, and a fire alarm is issued.

Problems to be Solved by the Invention However, the conventional configuration described above does not have a function to detect a disconnection state of the wiring for the sensor, and cannot detect the occurrence of a fire. However, in recent years, due to the spread of security equipment, demands from the market, compliance with technical standards based on the Fire Service Act, etc., there has been a demand for sensors to be able to detect disconnection states.

The present invention solves the conventional problems as described above.
The object of the present invention is to provide a fire alarm system for a residential unit that can detect disconnection of a sensor.

Means for Solving the Problems In order to solve the above problems, the present invention provides a first detection circuit that detects a disconnection state of a sensor that operates by sensing an abnormality in the installation atmosphere, and a first detection circuit that detects a disconnection state of a sensor that operates by sensing an abnormality in the installation atmosphere, and a first detection circuit that detects an operation of the sensor. a second detection circuit that detects the state; an alarm that lights up or makes a sound when in operation; and a drive means that also operates the alarm A based on the operation of either the first or second detection circuit. It is equipped with the following.

For production The present invention has the following effects due to the above configuration.

That is, by detecting the presence or absence of current flowing through a predetermined terminal of a sensor having a plurality of terminals, disconnection of the sensor can be detected. By driving an alarm such as an LED upon this detection, the connection can be broken.

EXAMPLES Hereinafter, examples of the present invention will be described with reference to the drawings. FIG. 1 is a circuit diagram showing the configuration of a fire alarm system for a residential unit according to an embodiment of the present invention, and FIG. 2 is a block diagram showing an example of a fire alarm system configured using the fire alarm system shown in FIG. 1. It is.

In FIG. 2, 11, 12-1n and 21, 22
...2n is the residential unit targeted for fire alarm, 311-31
411 to 41n and 421 to 42n are connected to the fire alarm devices for residential units 3u to 3tn and 321 to 32n, respectively, to detect abnormal temperatures in the atmosphere. It is a heat detector that detects rising temperatures. The fire alarm systems of each dwelling unit are connected in parallel, with fire alarm systems 311 to 31n serving as system 1, and fire alarm system 3 as system 1.
21 to 32n are system 2, and each line 6a, 6
b is connected to the center receiver 5.

7a and 7b are terminators of the center receiver 7, which are used to check whether each of the fire alarm devices is properly connected.

Figure 1 shows the configuration of the fire alarm system 3.
The configuration is common to each of xn and 321 to 3zn. Similarly, the heat detectors 4 are 411 to 41n and 421 to
The configuration is common to each of the 42n.

Here, for convenience of explanation, only the dwelling unit 11 of system 1 will be explained.

The fire alarm device 311 includes an input line Ll that connects the center receiver 5, output lines L2 and C2 that connect the C11 fire alarm device 312, and terminals P1 to P4 that connect the heat sensor 411. Lines C1, C2 and terminal P4 are grounded.

In FIG. 1, 11 prevents the current in the fire alarm device 311 from flowing to the line Ll side (Ni line L
a diode 12 for applying current from l to terminal P1;
13 is a photocoupler in which a light emitting diode and a phototransistor are integrated, which is connected to the resistor 12; 14 is between the light emitting diode (hereinafter referred to as LED) of the photocoupler 13 and the diode 11; This is a diode provided in the line Ll side to prevent reverse flow from the line Ll side.

15 is a current limiting resistor connected to the positive power supply, 16 is a resistor 15
This is a pull-up resistor provided between the phototransistor of the photocoupler 13 and the phototransistor of the photocoupler 13.

The above part numbers 11 to 16 constitute the second detection circuit 8, and operate when the heat sensor 411 operates in a normal state. On the other hand, the first detection circuit 9 is activated when the heat sensor 411 is disconnected, and is constituted by part numbers 17 to 20.

17 is a resistor connected to terminal P2, 18 is a resistor connected between resistor 17 and terminal P3, 19 is a pace connected to the connection point of resistors 17 and 18, and an emitter is connected to terminal P.
20 is a backflow prevention diode whose cathode is connected to the collector of transistor 19 to prevent current from flowing into other circuits from the direction of transistor 19; 21 is a diode of diode 20; This is a pull-up resistor connected between the anode and the positive power supply.

22 is a display element whose cathode is grounded and functions as an alarm that lights up depending on the operating state of the heat sensor 41-1 and the presence or absence of a disconnection; 23 and 24 are protective elements connected to the drive side of the display element 22; A resistor 25 is a diode connected in series with the resistor 23 to prevent the current flowing through the resistor 24 from flowing into other circuits. A buffer circuit 26 is connected in series with the diode 25 to drive the display element 22. It is. A diode 27 prevents the voltage from the resistor 15 from being supplied to the diode 20 and the buffer circuit 26;
8 is an inverter circuit that inverts and outputs the voltage applied through the resistor 15, and 29 is an on/off circuit with a 0.5 second cycle, for example.
This is an oscillator circuit that generates a square wave signal when it is off. 30 is a NAND circuit which performs the logical product of the output signal of the oscillation circuit 29 and the output signal of the inverter circuit 28; 31 is a resistor connected to the output terminal of the NAND circuit 30; and 32 is a base connected to the resistor 31. 33 is a resistor connected between the emitter and the base of the transistor 32.

Next, the operation of the embodiment with the above configuration will be explained.

In the configuration shown in FIG. 2, for example, if a fire breaks out in the dwelling unit 11 and the fire alarm device 311 is activated, the display element 22 in the fire alarm device 311 lights up and at the same time,
A signal is given to the center receiver 5 via line 6a,
It is possible to detect that a warning has been issued to system 1.

In the fire alarm device 311, the terminals P1 and P2, and Pa and P4 of the heat sensor 411 are in a short-circuited state during standby. By shorting terminals PI and P2, resistance 12 →
The same voltage is applied to terminal P1 in the path from photocoupler 13 to diode 14, and two currents 11 are flowing through resistors 17 and 18. This current i1 is set to a value that does not cause the light emitting diode of photocoupler 13 to light up.

The transistor 19 is turned on by the voltage generated across the resistor 18 as the current il flows, and the buffer circuit 2 is turned on.
Input No. 6 is set to "L" level.

At this time, a voltage is applied to the input of the inverter circuit 28 via the resistor 15, and the output of the inverter circuit is at the "L" level (:), and the output of the NAND circuit 30 remains at the "H" level, so the transistor 32 is in an off state.Since the output of the buffer circuit 26 as well as the transistor 32 is at the "L" level, the display element 22 is turned off.

Next, if any one of the terminals P1 to P4≦2 is disconnected from the heat sensor 411, the heat sensor 411
A loop passing through is no longer formed, and the current 11 no longer flows. As a result, transistor 19 is turned off,
A "H" level voltage is applied to the buffer circuit 26 via the resistor 21, and the output of the buffer circuit 26 becomes "H" level. Therefore, the same voltage is applied to the display element 22 using an LED or the like via the diode 25 and the resistor 23.
The display element 22 lights up continuously.

Next, when the heat sensor 411 is activated due to a fire or the like in a normal state with no disconnection, the terminals P1 and Pa, or PI and P4, P2 and Pa, or P2 and P4 become short-circuited. As a result, a current flows through the path of resistor 12 → photocoupler 13 → diode 14 → heat sensor 411 → ground. That is, a current larger than the above-mentioned current 11 flows, and the LED in the photocoupler 13 lights up. By lighting up the LED, the photocoupler 13
The phototransistor inside turns on, the input of the inverter circuit 28 becomes "L" level, and its output becomes "H" level.
” level.

When the output of the inverter circuit 28 becomes "H" level, the output of the NAND circuit 30 becomes "L" level, and the transistor 32 is turned on. When the transistor 32 is turned on, the display element 22 is energized and blinks. This blinking depends on the oscillation period determined by the oscillation circuit 29. Therefore, while the display element 22 was lit continuously when the first detection circuit 9 was operating, the blinking indicates whether the display is due to a disconnection or a fire. can be easily distinguished by the user.

As described above, according to the embodiments of the present invention, it is possible to automatically monitor whether the connection of the heat sensor is normal or abnormal based on the display state of the display element, and to simultaneously issue an alarm in accordance with the operation of the heat sensor. Security functions can be further improved. In addition, the operation of the heat sensor is such that the line Ll is "H".
The center receiver 5 is notified of the change from the level to the "L" level, and the center receiver 5 can ascertain whether or not an alarm has been issued.

In the above embodiments, a heat sensor was used as the sensor, but the present invention can be applied to any sensor whose output terminal is short-circuited during operation.

Effects of the Invention As described above, according to the present invention, disconnection of the sensor can be automatically monitored, so that the operating state of the fire alarm device can be accurately grasped.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of the present invention, and FIG. 2 is a block diagram showing an example of a fire alarm system using the fire alarm device of the present invention. 3u-3tn, 321-3zn--Fire alarm device, 411-41n, 421-42n...Heat sensing device, 5...Center receiver, 8...First detection device, 9... Second detection device, 22...Display element, 26
... Buffer circuit, 28 ... Inverter circuit, 30
...NAND circuit, 32...transistor. Name of agent: Patent attorney Toshio Nakao
2 figure

Claims (1)

[Claims] A first detection circuit that detects a disconnection state of a sensor that operates by sensing an abnormality in the installation atmosphere, a second detection circuit that detects the operating state of the sensor, and an alarm that lights up or sounds when operating. A fire alarm device for a dwelling unit, comprising: a fire alarm device; and a driving means for driving the alarm device based on the operation of either the first or second detection circuit.