CN2032718U

CN2032718U - Ion smoke-sensitive fire detector

Info

Publication number: CN2032718U
Application number: CN 88210275
Authority: CN
Inventors: 孙金海; 戴兵
Original assignee: Individual
Current assignee: Individual
Priority date: 1988-03-12
Filing date: 1988-03-12
Publication date: 1989-02-15

Abstract

The utility model discloses an ion sensing smoke fire detector. The utility model is characterized in that an integrated circuit composed of a linear amplifier and two complementary switch circuits is adopted, and the signal line and the check line adopt the same conductor which can directly output the variation characteristics of smoke density in working environment. The utility model has the advantages of small power consumption, big output current, conductor saving, high reliability, etc. The utility model can match with local fire alarm device, computer system and automatic fire extinguishing system. The utility model is a fire prevention safeguard and indispensable to all walks of life.

Description

Ion smoke-sensitive fire detector

The utility model relates to a kind of ion smoke detector, and it is fit to the exploring block in the mineral wool warning system.

Present ion smoke detector (with reference to figure 1) is surveying next signal directly as switch controlling signal, drive alarm work, reaching the purpose of fire alarm; The source S terminal voltage of this detector field effect transistor FED adopts electric resistance partial pressure given; Adopt a switch transition loop, and form by dispersive element; Adopt four lines (power supply+, power supply-, signal wire X, check line J); Drive the amplifier tube BG of alarm ₃Alarm lamp L and the resistance R of collector through being connected in parallel ₁₂With power supply+link to each other, therefore the problem that has following several respects: 1. can not follow-up work point (A) level, because environmental impact, after the detector long-term work, its working point level will drift about, if drift downwards, working point (A) level reduces, above field effect transistor FED conducting after the fire alarm threshold value, send fire alarm signal mistakenly; If upwards drift, working point (A) level increases, and causes detector sensitivity to reduce, slow movement or be failure to actuate during breaking out of fire, and this also is the main cause that current various smoke detector is often reported gentle newspaper by mistake.2. the monitored state current sinking is big.3. damage or interelement tie point when snapping when electronic component, can't realize fire alarm.4. establish special inspection line, the waste lead.5. output current is little, can not drive than heavy load.

The ion smoke detector that the purpose of this utility model provides that a kind of power consumption is little, output current is big, save lead, reliability is high.

The purpose of this utility model is achieved in that it comprises and detects ionization chamber, compensated ionization chamber, signal amplifying return circuit, switch transition loop, fire disaster simulation test check line, alarm lamp, it is characterized in that: add a linear amplifier between signal amplifying return circuit and switch transition loop, signal output part; Adopt two complementary switch change-over circuits; Linear amplifier and two complementary switch change-over circuits adopt an integrated circuit; The field effect transistor source electrode of signal amplifying return circuit links to each other with power supply by a current-limiting resistance, and the final stage in switch transition loop adopts emitter follower to export, and this output terminal and be connected to an amplifirer; Signal wire adopts same transmission line with checking line.During supervision,,, send into the fire controller through signal transmssion line by linear amplifier output and the proportional working signal of working point level, by be located at the fire controller on transfinite partially and descend the threshold value that transfinites partially, the drift situation of follow-up work level point.During breaking out of fire, linear amplifier output terminal working signal level increases, after reaching certain value, the conducting of trying to be the first in two switch transition loops, and pin another, drive alarm lamp and gate light, realize fire alarm, only need when checking circuit to add a high level, make the conducting of switch transition loop, reach simulated fire and report to the police at the signal wire output terminal.

Characteristics of the present utility model, standby current is little, and the big reliability of output current can improve more than several times.

Below in conjunction with accompanying drawing the utility model is further described:

The existing ion smoke detector schematic diagram of Fig. 1.

Fig. 2 the utility model theory diagram.

Fig. 3 the utility model electrical schematic diagram.

With reference to figure 2, the utility model is made up of detection ionization chamber 1, compensated ionization chamber 2, signal amplifying return circuit 3, linear amplifier 4, amplitude limit adjustment 5, switch transition loop 6,7, interlocking door 8,9, alarm lamp 10, amplifirer 11.Its principle of work is: monitored state, because the influence of environment, working point (A) level in the middle of detection ionization chamber 1 and the compensated ionization chamber 2 drift about, give linear amplifier 4 through signal amplifying return circuit 3 outputs one amplifying signal, make linear amplifier 4 outputs and the proportional working signal of working point level, deliver to the fire controller by signal transmssion line XJ.The drift situation of follow-up work level point, surpass be located in the fire controller on transfinite partially or transfinite partially down and just send failure alarm signal after the threshold value, notify the watch to overhaul or change detector, system is reliable with assurance.During breaking out of fire, combustion productss such as smog enter and detect ionization chamber 1, its impedance is changed, equiva lent impedance increases, and compensated ionization chamber's 2 smog can not enter, impedance does not change, therefore cause that two ionization chamber two ends intrinsic standoff ratios change, the working point level is lower, and signal amplifying return circuit 3 and linear amplifier 4 are amplified, when reaching certain value, adjust 5 through amplitude limit, make the conducting of trying to be the first in switch transition loop 6 or 7, and by interlocking door 8 or 9 one of pinning in switch transition loop 7 and 6, light alarm lamp 10 simultaneously, drive gate light through amplifirer 11 and send fire alarm signal to the fire controller through signal wire XJ.During mock survey, add a level (this level threshold value that transfinites partially on being higher than in the alarm controller at signal wire XJ end, but be lower than the fire alarm threshold value), adjust 5 by amplitude limit, make conducting in the switch transition loop 6,7, drive alarm lamp 10, drive gate light and send fire alarm signal back to by amplifirer 11 and signal wire XJ respectively, reach the purpose of test check circuit to the fire controller.

With reference to be integrated circuit in the frame of broken lines among the figure 3(figure, marking sequence number is the integrated circuit Wiring port) above-described each several part circuit is specifically composed as follows:

Detect ionization chamber 1 and compensated ionization chamber 2 by americium Am ²⁴¹Radioactive source is formed, as smog one level sensor.Detect ionization chamber 1 and be in communication with the outside, change its equiva lent impedance along with the variation of smokescope, compensated ionization chamber 2 is isolated from the outside, and smog can not enter, so impedance does not change.Two ionization chambers are connected in series, and a middle tie point A has level output, and this level is the working point level.

Signal amplifying return circuit 3 is by the field effect transistor PG of high impedance ₁And resistance R ₁, R ₂Form BG ₁Grid C link to each other BG with working point A point ₁Source S and drain D pass through resistance R respectively ₁And R ₂With power supply+, power supply-link to each other, adjust R ₂Resistance can change BG ₁Enlargement factor.

Linear amplifier 4 is by triode BG ₂, BG ₃, BG ₄, resistance R ₃Form.Its input end BG ₂Base stage (being integrated circuit 8 ports) and signal amplifying return circuit BG ₁Drain electrode connect output terminal BG ₄Emitter-base bandgap grading (being 10 ports of integrated circuit) and signal wire XJ adjust input end with amplitude limit and link to each other, when the level-shift of working point, signal amplifying return circuit drain D is exported an amplifying signal, passes to BG ₂Base stage, make BG ₂, BG ₃, BG ₄Conducting is by BG ₄Emitter-base bandgap grading output and the proportional working signal of working point level, give fire controller, the drift situation of follow-up work level point by signal wire transmits.During breaking out of fire, BG ₄After the working signal level of emitter-base bandgap grading output reaches certain value, adjust the conducting in gauge tap conversion loop by amplitude limit.

Amplitude limit is adjusted 5 and is adopted adjustable resistance R ₅, adjust resistance R ₅Resistance can adjust the detector action value, R simultaneously ₅Resistance size decision fire disaster simulation should add the amplitude of checking level at signal wire lamp XJ when checking.

Switch transition loop 6,7 is respectively by triode BG _5-9, resistance R _6-10, stabilivolt WD _1-2Diode D ₄, capacitor C ₂With triode BG _10-14, resistance R _11-15, stabilivolt WD _3-4, diode D ₈Form.C ₂Be to be attempted by BG ₅And BG ₁₀Base loop in a delay capacitor (being not included in the integrated circuit), the input end BG in two switch transition loops ₅And BG ₁₀Base stage and amplitude limit adjust R ₅Link to each other output terminal BG ₉And BG ₁₄Emitter-base bandgap grading respectively by diode D ₁And D ₅XJ links to each other with signal wire.During breaking out of fire, adjust R by amplitude limit by linear amplifier ₅The operation level of output is added in BG ₅And BG ₁₀Base stage on, be located at BG when surpassing ₇The base stage threshold level, make BG _5-9Conducting is amplified, and reports to the police to the fire controller by signal wire XJ, passes through D simultaneously ₃Drive alarm lamp, by interlocking door D ₂Give another conversion switch BG ₁₂High level of base stage pins this switch transition loop, passes through BG ₈, R ₉, D ₄Give BG ₅Base stage injects a big electric current, even if field effect transistor is ended BG _5-9As usual conducting, thus make detector have memory function.A damage in two switch transition loops, another is devoted oneself to work automatically, diode D ₂And D ₆Form two interlocking doors 8,9.

Alarm lamp 10 is made up of light emitting diode L, and an end passes through resistance R ₁₇With diode D ₃And D ₇Negative electrode link to each other, the other end links to each other with power supply one.

Amplifirer 11 is by triode BG ₁₅Form its base stage and diode D ₃And D ₇Negative electrode links to each other, and collector passes through resistance R ₁₆With power supply+link to each other, emitter-base bandgap grading drives gate light.

Claims

1, a kind of ion smoke detector, it comprises detects ionization chamber, compensated ionization chamber, signal amplifying return circuit, switch transition loop, fire disaster simulation inspection line, alarm lamp, it is characterized in that:

1. between signal amplifying return circuit and switch transition loop, signal output part, add a linear amplifier;

2. adopt two complementary switch conversion loops;

3. an integrated circuit is adopted in linear amplifier and two complementary switch conversion loops;

4. signal wire adopts same transmission line with checking line;

5. the field effect transistor source electrode of signal amplifying return circuit links to each other with power supply by a current-limiting resistance;

6. the final stage in switch transition loop adopts emitter follower output, and this output terminal and connect an amplifirer.