JPS5850475Y2 - Teiden Atsukasaikan Chiki - Google Patents

Description

[Detailed explanation of the invention] Recently, a fire detector has been developed that operates sequentially depending on the size of phenomena such as heat, smoke, gas, and light that occur with a fire, and generates two different types of signals. When the size of the above-mentioned phenomenon is relatively small, the sensor will issue a warning signal to display a warning and prepare the smoke evacuation equipment for operation. It has been proposed that a fire signal emitted when a fire occurs indicates a fire and activates smoke evacuation equipment, etc., but this idea uses a constant voltage device to stabilize the operation of such fire detectors. Regarding what has been established.

Many of the various fire detectors that have been developed in recent years use semiconductor circuits, and it is desirable for such detectors to have a constant voltage power supply in order to stabilize their operation. When connecting to a conventional receiver with
It is desirable to insert some kind of constant voltage circuit into the sensor.

It is the first ordinary fire detector equipped with a constant voltage circuit that has a single operating level and outputs a single output signal.
The one shown in the figure is known.

In the figure, A is a fire detection section including an amplifier circuit, D is a switching circuit, and E is a constant voltage circuit. It consists of a Zener diode ZD connected in parallel with T and a Zener current supplied through a resistor R connected between the pace and collector of T.

When such a sensor operates, a current higher than the current value of the receiving relay will flow, so unless a highly sensitive one with a small sensing current value is used as the receiving relay, the switching circuit will not be short-circuited. Since the constant voltage circuit E is designed to be in a similar state, the constant voltage circuit E will not be able to operate normally, and although this is fine when outputting a single signal, it will not be possible to output two types of signals one after another.

This idea is equipped with a constant voltage circuit to handle the heat generated in a fire.
A stable constant voltage fire that operates sequentially according to the size of phenomena such as smoke, gas, light, etc., and generates two different signals without any hindrance that can operate a receiving relay with normal sensitivity. The invention is aimed at obtaining a sensor, and the invention will be explained below with reference to embodiments shown in the drawings.

Figure 2 is a circuit diagram of a fire detector DE, which is one embodiment of this invention.It operates in sequence according to the size of the phenomenon associated with fire, for which a patent application was filed on January 2, 1975.There are two types of fire detectors. A fire detector that generates different signals is equipped with a constant voltage device.

The fire detector for which the patent application was filed (Japanese Patent Publication No. 57-3997) is characterized by the fact that it generates two types of signals without the need to provide separate signal generators for each, resulting in a simple configuration. As shown in Fig. 2, the fire detection part A and the detection part A operate sequentially depending on the temperature and the output size of the detection part A.
A signal generating device that generates different types of signals, which is formed by an operating level switching section B and a pulse voltage generating section C for periodically switching the operating level of the switching section B; The Zener diode ZD2 is omitted in the output signal generation section of the circuit, and the resistance value of the resistor R14 is increased instead. , B, and C are added based on this idea.

The fire detection section A includes a conductor t connected to a negative signal line t1 leading to the receiver via a transistor T6 in a constant voltage circuit E.
l, and a conductor t2/- directly connected to the positive signal line t2 leading to the receiver, and a thermistor Th as a heat-sensitive element connected through a resistor RO, and a base at the connection point p between the thermistor Th and the resistor Ro. an operation level switching section B, which is connected to a transistor T1 with conducting wires /, 1/, and 12 connected therebetween through a resistor R, which is connected to the emitter side, and forms the signal generating device together with the pulse voltage generating section C; Are the resistors R2 and R3? Conductor t1' through R4
.

A transistor T2 connected between ZZt and whose base is connected to the emitter of the transistor T1, a resistor R5 connected between the emitter of T2 and the conductor Z1t and forming a leader resistance together with a resistor R35R4, and a resistor between the base and emitter. Resistor R with R2 & and capacitor C1 in parallel
6, connected in parallel with the transistor T3 and the resistor R4, with the conducting wire Z t I ZZ connected therebetween through R7;
A transistor T4 whose conduction is controlled by a pulse voltage generating section C that periodically switches the operating level switching section B is connected to a conductor T1' through a resistor R8.

a capacitor C2 connected between Z2/ and an N-gate thyristor PU connected in parallel with C2 through a resistor R9.
T, and the conducting wire L11. /, 2/ A resistor R10sRo connected in series between the resistors R10sRo and their connection points connected to the gate of PUI', and a Zener diode ZD1 and resistors R12p and R13 connected in parallel with the resistor all.
A series circuit of
, are conductive, and the constant voltage circuit E consists of signal lines 1. A Zener diode zD3 connected between the base button of transistor T6 and the conductor Z 2 / and the base button of T6 and the conductor Z 2 /, and the capacitor C3
The base of the output signal generating section is the connection point between the resistors R6t and R7 of the operation level switching section B. A switching circuit is connected between the collector side of the transistor T6 and the conducting wire Z2t through the Zener diode (ZD2) as a constant voltage element, the low resistance R14 for current limiting, and the light emitting diode LD. It is constituted by a transistor T5.

Therefore, the capacitor C is passed through the resistor R8 to the pulse voltage generating section C that periodically switches the operating level switching section B.
2 is charged and the anode voltage of PUT becomes higher than the gate voltage, PUT starts conducting, and the Zener die, t-)'ZD, becomes resistor R11t R1 due to the increase in voltage drop across R11 due to the gate current flowing through resistor Ro.
3 and PUT (2) conducts through the gate and cathode.

The conduction with the capacitor C2 is maintained for a certain period of time until the capacitor C2 discharges through the resistor R9 and the PUT and the discharge current becomes less than the holding current value of the PUT, and then stops when the PUT stops conducting, but this operation is performed at a certain period. is repeated with resistance R
At 13, a pulse voltage having a pulse width r and a period T as shown in FIG. 3a is generated.

The horizontal axis of FIG. 3a shows time t, and the vertical axis shows voltage V.

Synchronized with this pulse voltage, the transistor T4 of the operation level switching section B becomes conductive and short-circuits the resistor R4. Therefore, the emitter voltage vb of the transistor T2, which determines the operation level of the signal generator, is plotted with time t on the horizontal axis. is shown by the broken line in Figure 3, where the vertical axis shows voltage vb and output voltage Va of fire detection part A as increasing upward in the negative direction with respect to the voltage of conductor t2/. 5, between the first operation level vb1 and the second operation level vb2
It changes with 0 width r period T.

On the other hand, the transistor T1 as the output voltage of the fire detection part A
The emitter voltage va is set lower than the operating level 71 and 1°vb2 of the sensor's signal generator under normal conditions, so this sensor does not operate, but in the event of a fire, the heat will cause the fire detection part A to The resistance of the thermistor Th gradually decreases, and accordingly, the emitter voltage va of the transistor T1 gradually increases upward in the negative direction as shown by curve a in FIG. 8, and reaches the first operating level Vb1 at time t1. When the voltage is exceeded, the transistors T2 and T3 become conductive one after another, and the voltage drop across the resistor R7 causes the transistor T2 to become conductive.
5 is also conductive, allowing a pulse current of sufficient magnitude to operate a receiving relay with normal sensitivity to flow through the lines t1 and t2, and at the same time, the Zener diode zD2 converts the time t on the horizontal axis and the voltage on the vertical axis. As shown in FIG. 3C, which shows line t1. Voltage V between t2.

The voltage v2 obtained by subtracting the voltage drop in the receiving relay and the signal line from the constant voltage circuit E is set to a voltage that allows the constant voltage circuit E to maintain its output voltage vl constant, and at the same time, the light emitting diode LD is caused to emit light for a period of time r.

The pulse current flowing through this line 11.12 is expressed by the time t on the horizontal axis.
As can be seen in FIG. 3d, where the vertical axis represents the current i, this occurs repeatedly each time the emitter voltage Va of the transistor T1 exceeds the first operating level Vb1, and at time t2 the second operating level is reached. When exceeding vb2, transistor T2
, T 3 , and T 5 successively become conductive and thereafter remain in the conductive state, and the light emitting diode LD continues to emit light.

These pulse signals and DC signals are distinguished by appropriate means by pressing a button on the receiver, the first pulse signal is used to display a warning and the necessary equipment is ready for operation, and the second DC signal is used to warn of a fire. It is possible to perform display and operate necessary equipment.

FIG. 4 is a circuit diagram of a fire detector DE which is a second embodiment. Compared to the embodiment of FIG. Instead, the internal ion chamber CHi, the external ion chamber CHo, and the field effect transistor FET are used to detect the concentration of fire smoke as the source voltage Va of the FET, and the transistor T is used as the operation level switching section B of the signal generator. Using an operational amplifier OP as a comparator which operates in the same way instead of the 2 t T 3 combination,
The circuit configuration is exactly the same, except that the reference signal vb, which determines the operating level applied to the upper input terminal, is switched depending on whether or not the transistor T4 is conductive. The corresponding parts are given the same reference numerals and their explanations are omitted.

Both of the above two embodiments relate to a fire detector in which two different signals are generated by periodically switching the operating level of the same signal generator into two stages. The present invention can also be applied to a fire detector in which two different signals are generated using different output signal generators with different operating levels.

FIG. 5 is a circuit diagram of a fire detector DE which is an embodiment of this invention regarding such a fire detector, and in the embodiment shown in FIG. In addition to removing the transistor T4 for the pulse voltage generation section CK-J? resistance R1
2f R] 3 Connect the mutual connection point to the base of the transistor T5 in the output signal generation section, disconnect the connection point between the pulse voltage generation section C and the conductor Z t t, and connect them with the transistor T4/. Then, when the source voltage Va of the FET in the fire detection section A exceeds the second operating level vb2, the operational amplifier OP conducts the transistor T5 in the output signal generation section and generates an output that causes a DC signal current to flow through the lines t1t and t2. Assume that another operational amplifier OP' is newly installed in which the connection point between the resistors R3+R4 is connected to the input terminal of the reference signal, and the source of the FET is connected to the other input terminal, and the connection point between the output terminal and the conductor t2I is The connection point between the resistors R6'tR7' connected in series with the transistor T
4/, and when the source voltage V& of the FET exceeds the first operating level vb1, the transistor T4/
conducts, the pulse voltage generating section C operates, and the pulse voltage generated in the resistor R13 as shown in FIG. This embodiment has the same circuit configuration as in Fig. 4, except that a pulse signal current as shown in Fig. d is passed, and in the event of a fire, the source voltage Va of the FET applied to the fire detection section A is negative. The pulse increases gradually in the direction, and when it exceeds the first operating level vb, similar to the embodiment shown in FIG. When the signal current exceeds the second operating level vb2, a similar DC signal current can be stably passed.

This idea can also be applied to detect phenomena such as gas and light in addition to the heat and smoke generated by fires.

As described above, the constant voltage fire detector of this invention operates sequentially depending on the magnitude of various phenomena associated with a fire, and stabilizes two different types of signals that can operate a receiving relay with normal sensitivity. It has the effect of being able to occur without any hindrance in a state where

[Brief explanation of the drawing]

Figure 1 is a circuit diagram of a conventional constant voltage fire detector, Figures 2, 4 and 5 are circuit diagrams of three different embodiments of this invention, and Figure 3 is a circuit diagram of a conventional constant voltage fire detector. FIG. 3d shows a pulse signal and a DC signal. A: Fire detection unit, B: Operation level switching unit of the signal generator, C: Pulse voltage generator of the signal generator, D: Output signal generator, z
D2... Constant voltage element in D, E... Constant voltage circuit.

Claims (1)

[Scope of utility model registration request] The fire detection section detects the magnitude of phenomena such as heat, smoke, gas, and light that occur with a fire, and operates sequentially depending on the magnitude of the output, sending two different types of signals to the signal line. A signal generator is equipped with a signal generating device that generates a signal from a nearby output signal generating section, a constant voltage element is connected in series with a switching circuit applied to the output signal generating section, and the output signal generating section and the fire detection section and the signal are connected in series. A constant voltage fire detector with a constant voltage circuit connected between the generator and the generator.