JPS60211599A - Malfunctioning preventor for fire alarm system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] 〔Technical field〕 This invention relates to a malfunction prevention device for fire alarm systems.

[Background technology]

Fig. 1 shows a schematic configuration diagram of a fire alarm system. Conventionally, in this type of fire alarm system, the receiver A DC voltage is applied between the connection line 21 and the common line -ec, and a smoke detector (1a), a heat sensor (1b), and a transmitter (3) are connected in parallel to the lines -e, -ec. ) is turned on, an excitation current flows through the receiving relay RY installed in each region in receiver A, and the receiving relay operates uniformly.The relay contact R forms a self-holding circuit and also connects other relay contacts. The connection circuit of the connecting terminal LA which generates an alarm output from the district alarm alarm output terminal B, and which also constitutes the energization path of the operation display lamp La in the transmitter (3). It is designed to pee. In the figure, SWo is a recovery switch.

Therefore, for example, even if the smoke detector (1a) temporarily operates due to smoke other than fire, there is a problem in that the receiving relay Ry of receiver A immediately operates, forming a self-holding circuit and issuing an alarm. .

[Purpose of the invention]

The present invention has been made in view of the above-mentioned problems, and its purpose is to prevent the reception relay of the receiver from operating due to a temporary malfunction of the sensor or transmitter, thereby improving the reliability of the system. The purpose of the present invention is to provide a malfunction prevention device for a fire alarm system that can improve the safety of fire alarm systems.

[Disclosure of the invention]

The present invention will be explained below with reference to Examples. FIG. 2 shows a circuit block diagram of an embodiment of the invention. In the figure, (6) is a constant voltage circuit section, and this constant voltage circuit section (6) is connected to the existing power output terminal Io, which is provided to supply DC power from the receiver A to the sub-receiver, etc., and a common line. The DC output between terminal C is stabilized to a DC output of a predetermined voltage, and is supplied as a power source to each circuit described below. (2) is a line voltage detection circuit section, and this line voltage detection circuit section (2) is connected to the common line -ec which is connected to the common line connection terminal C, and the sensor connection which is connected to the sensor connection line connection terminal. The voltage between wire 1□ is constantly monitored and the voltage is detected by the smoke detector (1a) and heat detector (1b).
Alternatively, when the transmitter (3) operates and detects that the voltage is below a certain level, it generates a detection output. (4) is a switching circuit section that turns on when a detection output is input and drives the high sensitivity relay (5) for a certain period of time.

The high-sensitivity relay (5) is a high-sensitivity type that operates faster than the time it takes for receiver A's receiving relay RydE to operate. Relay contact r before forming a self-holding circuit with relay contact r of receiving relay RY.

can be reversed from a normally closed contact to a normally open contact. When the normally closed contact side of the relay contact is inserted in series into the starting end of the common line 13c that connects the common line connection terminal C, when the normally closed contact side is opened, the common line I
Cut off between nc and common line connection terminal C, and connect common line -13c
And the sensor connection line! , a smoke detector connected between
1a) and the like, the excitation circuit of the receiving relay Ry in the receiver A is cut off. (7) is a timer circuit section, and this timer circuit section (7) starts a time-limited operation at the same time as the switch':J circuit section (4) returns to the OFF operation state, and during the operation period, the line voltage detection circuit section Even if (2) detects a change in line voltage and attempts to turn on the switch circuit section (6), it is forcibly maintained in the off state and a monitoring time is set. However, the constant voltage circuit section (1),
Line voltage detection circuit section (2) and switching circuit section (4)
), a timer circuit section (7), and a high-sensitivity relay (6) constitute a repeater-type malfunction prevention device (9) attached to the existing receiver A. Assuming we are in normal condition now,
The voltage applied between the sensor connection line and the common line IC hardly changes, and the detection output of the line voltage detection circuit section (2) is at a normal level. (4) does not work. Next, when the smoke detector (1a) detects smoke and turns on, it is connected to the sensor 9I'J device connection line C. As shown in FIG. 3(a), the voltage applied to both lines 4, & becomes lower, and this change is immediately amplified and discriminated by the line voltage detection circuit (2). If this change exceeds a predetermined level, the line voltage detection circuit (
2) generates a detection output of "Hl level" and turns on the switch circuit (4). This on operation drives the high-sensitivity relay (5), as shown in Figure 3 (b). The normally closed contact ro of the high-sensitivity relay (5) turns off, opening -ec to the common line.
, 'Receive relay RY, sensor connection line 11, relevant smoke detector (
1a), the receiving relay R formed by the common line -13cK
The energization path of Y's excitation current is cut off. In other words, the time required for the operation of the receiving sushi-Ry (for example, 10m5
If the high-sensitivity relay (5) operates earlier than ec) (for example, l m 5ec), the receiving relay RY does not operate and the receiver A does not issue an alarm. Now, the ON operation of the switching circuit section (4) is maintained for a certain period of time by a time constant circuit built in the switching circuit section (4).

During the ON operation of the switching circuit section (4), the common line I
Since the starting end of C is opened by turning off the normally closed contact of relay contact rO, the smoke detector (1a), which was being operated by the power supply from receiver A, will no longer operate and will return to normal operation. Then, the line voltage returns and the line voltage detection circuit section (2) no longer generates a detection output, and the switching circuit section (4) turns off. This turning off causes the high-sensitivity relay (6) to return to its original state, turning on the normally closed contact of the relay contact ro. This turns on the streak disease 1 again. t3
A DC voltage from the receiver A is applied between the terminals c and c. Power is also often supplied to the smoke detector (1a), but regardless of whether the smoke detector (la) is a photoelectric type or an ion type, there is a period from when the power is turned on to when it shifts to smoke detection operation. It takes several to 10 seconds for this to occur, and the smoke detector (1a) operates again a little later after the DC voltage is applied. This ON operation causes the line voltage to drop and the circuit voltage detection circuit section (2) again generates a detection output, turning on the switching circuit section (4) and driving the high sensitivity relay (5). In this way,
Every time the smoke detector (1a) is activated, the high sensitivity relay (5
) to prevent the receiving relay RY of receiver A from operating and self-holding. The operable time of this high-sensitivity relay (5) is defined by the time limit operation time of the switching circuit section (4). In other words, when the switching circuit section (4) turns off, it sends an output to the timer circuit section (7), causing the timer circuit section (7) to operate for a limited time as shown in FIG. 3(c), and during the time limited operation period, the switching circuit Part (4
) is forced off. Therefore, during the time limit operation period of the timer circuit section (7), the smoke detector (1a)
When activated, the reception relay RY of the receiver A is connected to the sensor connection line 41, the smoke detector (la), and the common line 1c.
An excitation current flows through the normally closed contact S of the relay contact ro, operating the receiving relay Ry75E, forming its self-holding circuit, and transmitting an alarm from the receiver A as shown in Fig. 3(d). It turns out. By the way, the timer circuit section (
If the smoke detector (1a) does not operate during the time-limited operation period (for example, 30 to 4 O5ec) of 7), the reception relay Ry75E of receiver A will not operate.
This indicates that the sensor operation during the on-operation period of the switching circuit section (4) was a temporary malfunction, which means that false alarms due to malfunction could be prevented. If the sensor operates after the time limit operation of the timer circuit section (7), the line voltage detection circuit section (2) and the switching circuit section (
4) and the highly sensitive relay (5), the line opening operation is performed in the same manner as described above.

〔Effect of the invention〕

The present invention includes a line voltage detection circuit configured as described above,
A switching circuit section and a timer circuit section are provided, and when the switching circuit section drives the switching means, the switching means opens at least a starting end portion of either the sensor connection line or the common line. During the operating period of the switching circuit section, the sensing operation of the sensor and transmitter can be interrupted, thereby preventing temporary malfunctions.Moreover, the time-limited operation of the timer circuit section allows the receiver's receiving relay to be interrupted. Since the operation period is set, if there is no alarm by the end of this period, the original state will be returned to prevent false alarms by the line voltage detection circuit, switching circuit, and timer circuit, thereby improving system reliability. It is something that can be improved.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram of a conventional example, Figure 2 is a line voltage detection circuit of the present invention, (3) is a transmitter, (4) is a switching circuit, (5) is a high sensitivity relay, (6) is the constant voltage circuit section,
(7) is the timer circuit, rO is the relay contact, Ry is the reception relay, Ishi is the sensor connection line, -ec is the common line Agent Patent Attorney Ishi 1) Long 7 Figure 3 (d)-17 1116 Yumi et al.

Claims (1)

[Claims] +l) Apply a DC voltage between the sensor connection line and the common line via the reception relay in the receiver, and connect a transmitter, heat sensor, or smoke detector between the sensor connection line and the common line. In a fire alarm system, the voltage applied between the sensor connection line and the common line is a line voltage detection circuit section that generates an output when the voltage drops to a predetermined level, a switching circuit section and a switcher circuit that drive a switching means whose operating time is faster than the receiving relay for a certain period of time based on the detection output of the line voltage detection circuit section. a monitoring timer circuit section that starts a time-limited operation when the switching circuit section returns to the off state and sets the switching circuit section in the off state until a preset time has elapsed to determine the monitoring time;
A malfunction prevention device for a fire alarm system, characterized in that when the switching means is driven by the switcher circuit section, the switching means opens at least a starting end portion of either a sensor connection line or a common line.