JP2862594B2 - Fire detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a fire detection system in which a plurality of receiving units such as a fire receiver and a repeater are connected and fire information relating to a fire phenomenon is transmitted to the receiving units. It is about a vessel.

[Prior art and problems] A plurality of fire detectors are connected to a fire receiver, and each fire detector is supplied with power from the fire receiver via a power line, and a signal processing unit in the fire detector generates a fire. When a fire signal is detected and a fire signal is output, the switch unit sends a fire signal to the fire transmitter, that is, short-circuits the power supply line or activates a relay etc. provided in the fire receiver as a very low impedance A so-called on-off type fire alarm device is known in which the occurrence of a fire is notified by causing the alarm to occur.

If the switch inside the fire detector is activated by the output of the fire signal and the power supply line is short-circuited or has a low impedance, to prevent unstable operation of the signal processing unit due to low voltage, The voltage detection unit provided in the first unit detects a short circuit or a voltage drop due to low impedance, and provides a reset signal to the signal processing unit.

However, when the power supply line is short-circuited or has low impedance at the time of a fire, the reduced voltage value is not constant due to variations in the relay of the fire receiver, the resistance of the power supply line, and the like, and is not close to the detection threshold of the voltage detection unit. In such a case, if the reduced applied voltage fluctuates due to external noise or the like, the voltage detection unit changes the “H” or “L” level to the signal processing unit. A repeated unstable reset signal will be given.

As a result, the signal processing unit repeats the unstable operation of the operation / cancellation by the “H” or “L” level of the reset signal repeatedly input under the unstable power supply voltage. When the unit is constituted by a microprocessor or the like, normal program processing is disturbed, and unintended operations cause problems such as loss of environmental data that should be originally stored.

[Means for Solving the Problem] Therefore, according to the present invention, a signal from an environment detection unit that is supplied with power from a remotely provided power supply via a power supply line and detects a physical quantity of an environment related to a fire phenomenon is provided. A signal processing unit that repeats an operation state of performing a fire determination by performing processing based on a predetermined processing procedure, and a standby state, and monitors a voltage to each internal circuit including the signal processing unit,
A voltage detection unit that outputs a reset signal for the signal processing unit when the monitoring voltage is equal to or less than a predetermined value, and a fire determination of the signal processing unit is performed when it is determined that a fire has occurred. A switch unit for outputting a reset signal for the signal processing unit while the power supply line has a low impedance in order to notify a fire occurrence to a remote place during operation. Is provided.

According to another aspect of the present invention, an operation state for performing a fire determination by processing a signal from an environment detection unit that detects a physical quantity of an environment related to a fire phenomenon based on a predetermined processing procedure, and a standby state Monitoring the voltage to each internal circuit that also includes the signal processing unit,
A voltage detection unit that outputs a reset signal for the signal processing unit when the monitored voltage is equal to or less than a predetermined value; and a signal processing unit that requires a predetermined time or more when the voltage detection unit outputs the reset signal. And a signal prohibition unit for prohibiting the reset signal from the voltage detection unit from being supplied to the signal processing unit until the processing is completed.

[Operation] In a fire detector supplied with power from a remotely provided power supply via a power supply line, the signal processing unit outputs the signal when the switch unit is operating, in addition to the reset signal from the voltage detection unit. Also receives a reset signal. In this way, when a fire occurs, a stable reset signal is supplied to the signal processing unit by the in-operation signal of the switch unit to bring the signal processing unit into a state instructed by a reset signal such as a standby state, and the reset signal is released. This operation is performed when the operation of the switch unit is stopped and a voltage equal to or higher than a predetermined voltage is detected by the voltage detection unit, and the reset can be reliably released.

According to another aspect of the present invention, when the reset signal is output from the voltage detection unit, the reset signal from the voltage detection unit is used for a predetermined time or more and until the signal processing unit completes necessary processing. The signal is prohibited from being given to the signal processing unit. Thus, supply of an unstable reset signal to the signal processing unit due to chattering or the like at the time of turning on the power to the fire detector or at the time of a recovery operation at the fire receiver and the repeater can be avoided.

Embodiment FIG. 1 is a block circuit diagram showing a fire detector according to an embodiment of the present invention, in which RE is a fire receiver,
SE is a fire detector in which a plurality of fire detectors are connected in parallel to the fire receiver RE, only one of which is shown.

In the fire detector SE, FS is an environment detector that detects physical quantities related to environmental fire phenomena, and PF processes signals from the environment detector FS and outputs a fire signal when it is determined that a fire has occurred. A signal processing unit composed of a microcomputer, etc., CV is a low voltage unit that stabilizes the voltage applied from the fire receiver at normal times to a constant voltage and supplies it to the internal circuit, and DT is a power supply voltage to the signal processing unit PR. A voltage detection unit that monitors and outputs a reset signal when the voltage is equal to or less than a predetermined voltage, HD is a signal holding unit for holding a fire signal from the signal processing unit PR, and SW is a fire signal from the signal processing unit PR. A switch section that turns on and sends a current increase signal or a short circuit signal as a fire signal to the fire receiver RE. OR is a signal based on a logical sum of a reset signal from the voltage detection section DT and an operation signal of the switch section. For processing unit PR An OR logic unit that gives a reset signal is a capacitor that supplies backup power to the signal processing unit PR even when the power supply from the fire receiver RE is temporarily cut off.

In the fire detector RE, E is a power supply for supplying power to the fire detector SE, and RL is a normally open contact that is activated by the operation of the switch SW when a fire occurs in the fire detector SE. The relay as a fire signal detector that closes a, the LP is a fire light that lights up when the contact a is closed to indicate a fire, and the SW _A is always closed, and the signal of the fire detector is retained by closing it. A recovery operation unit for releasing the holding of the unit HD.

First, when the power is turned on, the voltage detection unit DT of the fire detector SE is a signal processing unit until the power supply becomes stable.
A reset signal is given to PR, thereby setting the signal processing unit PR in a reset state and preventing malfunction.

In a steady state, the signal processing unit RP is supplied with a constant voltage by the constant voltage unit CV, and performs fire determination by inputting environment information from the environment detection unit FS.

When determining that a fire has occurred, the signal processing unit PR outputs a fire signal to the signal holding unit HD. The fire signal is held in the signal holding unit HD, the switch unit SW is operated, and the fire receiver
Activate relay RL in RE. As a result, the fire indicator light LP
Lights up to indicate a fire.

Since the voltage applied to the fire detector SE decreases due to the operation of the switch SW, the voltage detector DT detects this voltage decrease,
A reset signal is given to the signal processing unit PR via the OR logic unit OR, and at the same time, a signal indicating that the switch unit SW has been operated is also signaled via the OR logic unit OR as a reset signal. It is given to the processing unit PR. As a result, when the switch SW is operated, the signal processing unit PR is reset, the signal processing is stopped, and a transition is made to a predetermined state such as a standby state or a stop state.

As described above, when the switch section SW operates, the voltage detection section DT
The signal processing unit PR is reset based on the operation signal of the switch SW instead of resetting the signal processing unit PR only based on the voltage drop signal from the The unit PR can be stably and reliably reset.

FIG. 2 shows the voltage detection unit DT and the switch unit SW in more detail.

In the voltage detection unit DT, the + terminal of the comparator CM, is given a reference voltage by a constant current source CI and the resistance r _1, -
Voltage value proportional to the power supply voltage of the power supply line l ₂ to be monitored by the resistance r ₂ and r ₃ are given to the terminal. When the voltage value applied to the − terminal becomes lower than the reference voltage applied to the + terminal, the comparator CM outputs an “H” level signal or a high potential signal to output the field effect transistor TR.
₁ is turned on.

The potential of the point P is connected to the reset input terminal of the signal processing unit PR, by the power supply voltage of the power supply line l ₂ is given through a resistor r _4, normally a "H" level or a high potential ing. That is, in the example of FIG. 2, when the potential of the point P is high, the signal processing unit PR is not reset,
It is assumed that it is reset when it becomes “L” level or low potential. Therefore, although omitted in the figure,
Actually, in order to match the potential of the point P in FIG. 2 with the output of the OR logic OR in FIG. 1, it is necessary to invert the potential of the point P by an inverter or the like and to apply the inverted potential to the reset input of the signal processing unit PR. It is.

Therefore, comparator CM - supply voltage terminals, + the field-effect transistor TR ₁ comparator CM drops than the reference voltage and outputs a high potential signal at the terminal becomes a conductive state, to a ground potential the potential of the point P As a result, the reset signal is given to the signal processing unit PR.

In the switch section SW, the transistor TR ₂
When the signal holding unit HD outputs a high-potential signal at the time of a fire, it becomes conductive, and the power supply line l ₁ from the fire receiver RE is short-circuited or extremely low-potential via the resistor r ₇ , whereby the fire receiver The relay RL in the RE will be activated.
Moreover, in this way the transistor TR ₂ is turned, the potential of the point P via a diode DI for connected reverse blocking to the collector of the transistor TR ₂ is set to the ground potential is substantially short-circuited, thereby A low potential reset signal is supplied to the signal processing unit PR.

Thus from Figure 2, the signal processing section PR is seen that the reset state by any of the operation of the voltage drop or the switch portion SW of the line l _1.

After fire to fire action has been performed, in order to recovery, the recovery operation unit SW _A in according the receiver RE is manipulated. When the recovery operation unit SW _A is operated as shown in FIG. 1, relay RL is deenergized with contact a open to the fire indicator lamp LP is turned off, fire via a line l ₁ from the power supply E The power supply to the fire detector SE is cut off, whereby the signal holding unit HD and the switch unit SW of the fire detector SE are restored.

In this case, the reset signal to the signal processing unit PR is released only when the operation of the switch unit SW is restored and the voltage applied to the signal processing unit PR becomes equal to or higher than a predetermined voltage. Becomes an operating state, and the signal processing operation can be restarted from a step determined by a program (not shown), for example, a step where processing is stopped by a reset signal or an initial setting step.

FIG. 3 is a block circuit diagram showing another embodiment of the present invention. In FIG. 3, the different parts from FIG.
From the voltage detector DT, the signal inhibit section instead of the OR logic section OR
A signal is supplied to the signal processing unit PR via the IH, and the other parts are the same as those in FIG.

The role of the signal prohibition unit IH is to prohibit the input of unstable reset signals to the signal processing unit PR due to chattering when turning on the power to the fire detector SE or when performing a recovery operation with the fire receiver RE. It is in.

That is, in the signal processing unit PR, when the reset signal given to the reset terminal R of the signal processing unit PR is released, a predetermined time has elapsed since the release, and all processes required for initial setting and the like are performed. until it ended is confirmed, it outputs a control signal from the terminal I to the terminal T ₂ of the signal prohibiting unit IH. The signal prohibiting section the IH, while the control signal to the terminal T ₂ is given, that the unstable reset signal supplied from the voltage detection unit DT to the terminal T ₁ is is reentered terminal R of the signal processor PR Ban.

An example of the near signal section IH is shown in FIG. Similar to FIG. 2, the reset signal is set to "L" level signal from the terminal T _3, control signal from the signal processing unit PR, that is, the signal output from the terminal I when prohibit reset signal "H "It is a level signal.

If when the "L" level signal to the terminal T ₂ is given, since the one terminal of the AND logic AND via the inverter IV ₁ is given a high potential, of the AND logic unit AND gate and open and, therefore, if the signal is "L" level from the voltage detection unit DT given to the terminal T _1, the output signal from the terminal T ₃ by the inverter IV ₂ and IV ₃ also becomes "L", the reset The signal is provided to a terminal R of the signal processing unit PR. While a predetermined time elapses after the reset signal is supplied to the terminal R and until a necessary processing operation is completed,
The terminal T ₂ of the signal prohibiting unit IH from the terminal I is "H" level signal is applied, thereby the gates of the AND logic AND closed, the signal supplied from the terminal T ₃ to the terminal R of the signal processor PR Is always at “H” level, and thus the signal processing unit
Input of the reset signal to PR is prohibited.

In the embodiment shown in FIG. 3, the fire detector makes a fire judgment, and when a fire occurs, the power supply line is short-circuited or has a low impedance so that only the fire judgment result is received by a receiver such as a fire receiver or a repeater. In this example, the fire detector sends the environmental information from the environment detector to the receiver. To do
It can be easily understood that the embodiment of FIG. 3 can be applied to a so-called analog fire alarm device.

[Effects of the Invention] As described above, according to the present invention, the signal processing unit is configured to receive not only the reset signal from the voltage detection unit but also the reset signal output when the switch unit is operating. In a fire detector powered by a remotely provided power supply via a power supply line, when a fire occurs, a stable reset signal is supplied to a signal processing unit by a signal during operation of a switch unit, and the reset signal is released. Is performed when the operation of the switch unit is stopped and a voltage equal to or higher than a predetermined voltage is detected by the voltage detection unit, and there is an effect that the reset can be surely released.

Further, according to another aspect of the present invention, when the reset signal is output from the voltage detection unit, the reset signal is output from the voltage detection unit for a predetermined time or more and until the signal processing unit completes the necessary processing. A signal prohibition unit is provided to prohibit the reset signal from being given to the signal processing unit.This means that when power is turned on to the fire detector or when a fire receiver or repeater performs a recovery operation, a signal such as chattering is generated. There is an effect that supply of an unstable reset signal to the processing unit can be avoided.

[Brief description of the drawings]

FIG. 1 is a block circuit diagram showing a fire detector according to a first embodiment of the present invention, and FIG. 2 is a circuit diagram showing a voltage detector and a switch unit for generating a reset signal in FIG. 1 in more detail. FIG. 3 is a block circuit diagram showing a fire detector according to a second embodiment of the present invention, and FIG. 4 is a circuit diagram showing the signal prohibition unit of FIG. 3 in more detail. In FIG, RE is the fire receiver, SE fire detector, l ₁ is the power supply line,
FS is environment detector, PR is signal processor, DT is voltage detector, CV
Is a constant voltage section, HD is a signal holding section, SW is a switch section, SW _A is a recovery operation section, RL is a relay, E is a power supply, LP is a fire indicator,
IH is a signal prohibition unit.

Claims (2)

(57) [Claims] 1. A method according to claim 1, wherein a signal is supplied from a remotely provided power supply via a power supply line and a signal from an environment detection unit for detecting a physical quantity of an environment related to a fire phenomenon is processed based on a predetermined processing procedure. A signal processing unit that repeats an operation state for performing a fire determination, and a standby state; and monitors a voltage to each internal circuit including the signal processing unit. When the monitored voltage is equal to or less than a predetermined value, the signal processing unit A voltage detection unit that outputs a reset signal, and is operated when it is determined that a fire has occurred as a result of the fire determination of the signal processing unit, and the power supply line has a low impedance to notify the fire occurrence to the remote. And a switch unit that outputs a reset signal for the signal processing unit during operation. 2. A signal processing unit which repeats an operation state for performing a fire determination by processing a signal from an environment detection unit for detecting a physical quantity of an environment relating to a fire phenomenon based on a predetermined processing procedure, and a standby state. A voltage detection unit that monitors a voltage to each internal circuit including the signal processing unit, and outputs a reset signal for the signal processing unit when the monitored voltage is equal to or less than a predetermined value; A signal prohibition unit that prohibits a reset signal from the voltage detection unit from being supplied to the signal processing unit for a predetermined time or more and until the signal processing unit completes necessary processing when the reset signal is output. And a fire detector comprising: