UA23246U - Fire signal device - Google Patents

Abstract

The utility model relates to fire signal devices. Smoke fire signal device includes pulse generator, smoke indicator, connected ion sequence amplifier and pulse detector, and threshold unit. To increase reliability and safety smoke indicator additionally has IR emitter connected to third input of pulse generator. Two IR emitters and two IR receivers installed one in front of another form two slot optoelectronic couples.

Description

Description of the invention

A useful model relates to fire alarms, namely fire alarms.

A known smoke fire detector including a pulse generator and a series-connected smoke sensor, amplifier, pulse detector and threshold device, the smoke sensor comprising an IR receiver, a light-tight barrier and an IR emitter connected at the input to the first output pulse generator, the second output of which is connected to the second input of the pulse detector |H.M. Karnaukhov, E.A. Karnaukhov in the book "Large fire: warning and extinguishing". Material! KhMI scientific and practical conference. M. FSU 70. VnNIIPpO of the Ministry of Internal Affairs of Russia, 2001, p. 216-218).

However, the known device has insufficient operational reliability.

The closest in terms of technical essence to the smoke fire alarm that is claimed is the "fire alarm of the Karnaukhovs" |patent KO Mo2234737, MPKOO8В17/10, publ. 08/20/2004|.

The fire detector contains a smoke sensor, which contains a housing with slots, inside which is installed 12 light-impermeable partitions with a triangular cross-section with an angle of inclination of the faces of 20-70°. An IR emitter and an IR receiver are mounted on the opposite sides of the partition faces, each IR emitter and IR receiver are made with cross-sectional diagrams of reception radiation. In the sensor housing, a noise interference sensor is vertically installed, made in the form of an IR receiver, with a reception diagram in the range of 2-152, oriented outside the visibility zone of the IR radiation diagram of the emitter. The sensor and IR receiver are made of the same type of photodiodes. Directivity diagrams of the IR emitter and IR receiver are formed by installing the appropriate diaphragms or formed optics. The outputs of the IR receiver and noise interference sensor are connected oppositely to the inputs of the noise interference compensator. The compensator is made in the form of a series-connected current amplifier of the carrier signal and a current-to-voltage converter. The output of the compensator is connected through the amplifier to the first input of the pulse detector, the second input of which is connected to the second output of the pulse generator, the second output of which is connected to the input of the IR emitter. The output of the pulse detector is connected to the input of the threshold device through the amplitude converter of the pulse duration signals and the integrator. The threshold device is made in the form of a trigger that produces an alarm signal.

The work of a fire announcer consists of the following.

Under the influence of signals from the output of the IR pulse generator, the emitter periodically emits IR pulses. When smoke enters through the slits in the intersection of the directional diagrams of the IR emitter and the IR receiver, the latter receives the IR signals reflected from the smoke particles and outputs the corresponding electrical signal to the first input of the interference compensator. At the same time, the second input of this compensator receives a noisy scattered IR signal from the sensor body. Thermal and background interference is compensated due to the counter-inclusion of the IR receiver and the sensor in the interference compensator Ge).

In addition, when the upper part of the sensor housing is smoky, the input signal at the cm input of the sensor decreases and an additional uncompensated fire signal appears at the input of the compensator. In the compensator, the current of the carrier signal is amplified and the direct current is converted into voltage. The signal voltage from the output of the compensator through the amplifier is fed to the first input of the pulse detector, to the second input of which a selection pulse from the pulse generator is fed. -at

The selective signal from the output of the pulse detector is fed to the converter, where the amplitude of the signal c is converted into the duration of the pulse. The received signal is fed to the integrator. At the same time, the potential is accumulated in the integrator "z", which is transferred to the input of the threshold device (trigger). When the voltage at the output of the integrator reaches the threshold value for triggering the trigger, the latter is inverted and the fire signal in the form of a potential voltage from the output of the trigger is transmitted to the annunciator output. 15 Installation between the pulse detector and the threshold device of the converter of the amplitude of the pulse signal into the duration and the integrator allows to additionally reduce the probability of incorrect activation of the annunciator from (95) external electromagnetic signals. t The disadvantage of this fire alarm is the fact that the IR signal reflected from the smoke sensor housing and falling on the noise sensor depends not only on the presence of smoke, but also on the dustiness of the reflective walls of the housing. As a result, the carrier signal of the smoke sensor and the noise sensor,

Ф will also depend on the dustiness of the housing walls, which makes the compensation incomplete and preserves the possibility of incorrect operation.

The authors faced the task of increasing the reliability and reliability of the fire detector, that is, to minimize the probability of false alarms, by eliminating the effect of dustiness of emitters, receivers and the case on the sensitivity of the detector to smoke. c The technical result is achieved in that the claimed smoke fire detector, which includes a pulse generator, a smoke sensor, a series-connected amplifier and a pulse detector, as well as a threshold device, and the smoke sensor contains two IR receivers and an IR emitter, with connected at the input to the first output of the pulse generator, the second output of which is connected to the second input of the pulse detector, an interference compensator 60, a pulse duration signal amplitude converter and an integrator, the outputs of both IR receivers are connected through the mentioned interference compensator to the input of the amplifier, and the output of the pulse detector through the converter of the signal amplitude into the duration of the pulse and the integrator is connected to the input of the threshold device, according to the useful model, the smoke detector additionally contains 14 - an emitter connected to the third output of the pulse generator, at the same time, two IR emitters and two The IR receivers, which are installed opposite each other, form two slit optocouplers.

The design of the declared fire alarm allows to exclude the influence of dustiness of the body of emitters and receivers on the reliability of work.

Due to the design of the declared fire alarm, both optocouplers will have the same degree of dustiness, as a result of which, the carrier signal of two IR receivers in the absence of smoke will be strictly equal to zero, regardless of the level of dustiness of the housing.

The essence of the useful model is explained by the drawing, which shows the scheme of the proposed fire alarm.

The following marks are given on the drawing: 70 1 - fire alarm body; 2 - slots;

C - IR emitters; 4 - IR - receivers; 5 - noise interference compensator; 15 6 - amplifier; 7 - pulse detector; 8 - pulse generator; 9 - amplitude converter of pulse duration signals; - integrator; 11 - threshold device; 12 - IR radiation pulses.

The fire detector contains a smoke detector, which includes a housing 1 with slots 2, inside which two IR emitters C with a small aperture are installed, which are installed, respectively, against each other, forming two slit optocouples 3-4 and two identical IR receivers 4 (IR - photodiodes). The outputs of the IR photodiodes 4 are connected to the inputs of the noise interference compensator 5, which is made in the form of a series-connected current amplifier of the carrier signal and a current-to-voltage converter. The output of the compensator 5 Through o, the amplifier b is connected to the first input of the pulse detector 7, the second input of which is connected to the second output of the pulse generator 8, the first and third outputs of which are connected to the inputs of the IR emitters 3. Output of the pulse detector / through the converter 9 of the amplitude of the pulse duration signals and the integrator 10, it is connected to the input of the threshold device 11. The threshold device 11 is made in the form of a trigger that produces an alarm signal. -

The fire detector works as follows. Under the influence of signals from the output of the generator 8, the IR emitters З s periodically emit IR pulses 12. When smoke enters the gap between the emitters З and the receivers 4 through the slits 2, the carrier signal of two photodiodes 4, switched on oppositely, enters the two inputs of the interference compensator 5. Since at the initial stage of the fire, the smoke flow is pulsed in nature, its density is spatially heterogeneous, as a result of which the absorption intensity of IR pulses 12 on one and the other slit optocoupler 3-4 will be varied.

In addition, the IR pulse of the optocoupler, where the concentration of smoke is higher, will be partially scattered and fall on the photoreceptor of another optocoupler, which will cause the appearance of an additional uncompensated fire signal.

At the input of compensator 5. This increases the sensitivity of two differentially switched slit optocouplers 3-4. with c In the compensator 5, the current of the carrier signal is amplified and the direct current is converted into voltage. The signal voltage from the output of the compensator 5 through the amplifier 6 is fed to the first input of the pulse ;" detector 7, the second input of which is supplied with a selection pulse from the pulse generator 8.

The selective signal from the output of the pulse detector 7 is fed to the converter 9, where the signal amplitude is converted into the pulse duration. The received signal is fed to the integrator 10. At the same time, the potential accumulates in the integrator 10 and is transmitted to the input of the threshold device 11 (trigger). When the voltage at the output of the integrator 10 reaches the threshold value for triggering the trigger 11, the latter is turned over and the fire signal in the form of a potential voltage from the output of the trigger 11 is transmitted to the output of the annunciator.

The proposed technical solution allows to increase the reliability and reliability of the detector by reducing the probability of its incorrect operation, especially in the initial stage of the fire. Provided

Ф compensation of background interference and temperature fluctuations.

The claimed utility model can be widely used in fire alarm systems to effectively detect the initial stage of fire. with

Claims (1)

The formula of the invention is a smoke fire detector, which includes a pulse generator, a smoke sensor connected in series to an amplifier and a pulse detector, as well as a threshold device, and the smoke sensor contains two IR receivers and an IR emitter connected at the input to the first output pulse generator, the second output of which is connected to the second input of the pulse detector, the interference compensator, the amplitude converter of the pulse duration signal and the integrator, the outputs of both IR receivers are connected through the mentioned interference compensator to the input of the amplifier, and the output of the pulse detector is through the signal amplitude converter in the duration of the pulse and 65 the integrator is connected to the input of the threshold device, which differs in that the smoke sensor additionally contains an IR emitter connected to the third output of the pulse generator, at the same time, two IR emitters and two IR receivers, which are installed respectively against each other, form two slit optocouples. - (Se) «I se Ge) s - with . a ko (95) ko t» 4) s bo b5