CN203480616U

CN203480616U - Household bridge-type alarm

Info

Publication number: CN203480616U
Application number: CN201320406281.1U
Authority: CN
Inventors: 邬启兵
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-07-09
Filing date: 2013-07-09
Publication date: 2014-03-12
Anticipated expiration: 2023-07-09

Abstract

The utility model discloses a household bridge-type alarm and belongs to the technical field of security. The alarm consists of a touch sheet, a bridge early-warning unit, an alarm starting unit, and an on-site alarm unit. The touch sheet is disposed on a lockhole, and covers the lockhole and a lockhole switch in the alarm starting unit. When a person tries to crack the lockhole, a touch signal is generated. The signal reliably starts the on-site alarm unit to give an alarm after being amplified by the bridge early-warning unit. If the person is not stopped, the touch sheet just loosens, and the contact of the lockhole switch changes to generate an alarm starting signal. The alarm starting signal accurately starts the on-site alarm unit to give an alarm after being amplified by an electronic self-locking circuit in the alarm starting unit, thereby further improving the performances of products of an antitheft type, and increasing the types of antitheft products.

Description

Household electric bridge-type alarm

Technical field

Belong to safety technique field.

Background technology

Family is the bay of life, and family public security facility is sound, is conducive to people and works contentedly, and is conducive to harmonious life, is the primary demand of each family.

Anti-theft safety door is basic security personnel's equipment; in numerous anti-theft safety doors; the alarm being equipped with is all to only have in flagrant delict just to produce and report to the police, cannot at the beginning of crime, just send warning and be prevented, and with regard to anti-theft safety door, can only be just the protection of passive type like this.But solve " initiatively " protection, produced again a new difficult problem: how to reach alarm and there is lead? and had lead, which type of method to improve the dynamics of reporting to the police by again? for a long time, such difficult problem can not be properly settled all the time.

Antitheft series products, the startup of reporting to the police is critical element, if because start bad and cause can not and alarm, the consequence of generation is very serious, if there is malfunction when nil case, in the course of time just lost trust, consequence is also very serious, and that accomplish to report to the police and start is reliable, needs combinations mechanical and electronics two aspects, but to just can reach and start reliable requirement with which type of physical construction and which type of electronic circuit, also become a difficult point.

Exactly because above-mentioned difficult point, so present antitheft series products is also not very outstanding, solve the above problems, and also requires further study.

Summary of the invention

For improving the dynamics of reporting to the police, fundamental purpose of the present invention is to make full use of the existing patent of inventor and technological achievement, a kind of new technical measures are proposed again, the feature of this measure is just, to have had the beginning of crime, or the preparatory stage, can send immediately a kind of pre-warning, prevent, there is so better prevention effect, antitheft series products is obtained further perfect.

The technical solution used in the present invention is:

1, household electric bridge-type alarm is by touch sheet, electric bridge prewarning unit, and warning start unit, onsite alarming unit forms jointly.

Warning start unit is by lockhole switch and electric timing switch the electric circuit constitute.

Lockhole switch is arranged on lockhole top, touch sheet below, and touch sheet is oppressed the button of lockhole switch after being fixed on door, and lockhole switch contact is drawn with wire, connecting electronic latching circuit.

Electronic self-locking circuit is: with lockhole switch contact extension line, connect the base stage of a NPN amplifying triode after the series connection of input resistance, the grounded emitter line of NPN amplifying triode, one end of steady resistance connects the base stage of NPN amplifying triode, other end ground wire; The base stage of the rear connection PNP amplifying triode of a commissure resistance of collector series connection of NPN amplifying triode, the emitter of PNP amplifying triode connects 12 volts of power supplys, and the resistance of sealing up a door is connected between the emitter and collector of PNP amplifying triode; Isolating diode positive pole is connected on the collector of PNP amplifying triode, negative pole is connected on one of feedback capacity and extremely goes up, the negative pole of isolating diode has also connect over the ground one and has put remaining resistance, is connected to the base stage of NPN amplifying triode after another utmost point serial Feedback resistance of feedback capacity and feedback diode; Another utmost point of this electric capacity has also connect a discharge resistance over the ground, and PNP amplifying triode collector is connected in onsite alarming unit.

Bridge type prewarning unit by transformer unit, the preposition unit of bridge type, penetrate with isolated location, amplifying unit and form.

With transformer unit, connected the preposition unit of bridge type, the preposition unit of bridge type has connected to be penetrated with isolated location, penetrates with isolated location and has connected amplifying unit, and amplifying unit has connected onsite alarming unit; With the wires touch sheet sheet metal of ining succession, the other end of this metal wire has connected the preposition unit of bridge type after having connected a commissure electric capacity.

The connection of transformer unit is; The positive pole that connects respectively two diodes with the secondary two ends of transformation, secondary central shaft heads ground connection, has connected two-way after the negative pole of two diodes links together, and the first via has connected working power, the second tunnel has connected the positive pole of an electric capacity, the minus earth of this electric capacity.

The preposition unit of bridge type is that rectifier cell in electric bridge and the electric capacity in electric bridge form; Two diodes of the rectifier cell in electric bridge are composed in series a new branch road, and two diode series connection points become the outside output terminal of the preposition unit of bridge type; Another two diodes are composed in series another new branch road, and its series connection point connects ground wire; The positive pole of two new branch roads links together, and becomes bridge rectifier circuit positive pole, and negative pole connects together, as the negative pole of bridge rectifier circuit.

With the electric capacity one in electric bridge, be connected the positive terminal of rectification circuit with one end of electric capacity two in electric bridge, the other end of the electric capacity one in electric bridge has connected one end of primary, and the other end of the electric capacity two in electric bridge has connected the other end of primary; Electric capacity three in bridge rectifier circuit negative pole connection electric bridge and one end of the electric capacity four in electric bridge, the electric capacity three elementary one end of other end connection transformer in electric bridge, the other end of the electric capacity four in electric bridge has connected the other end of primary.

Penetrate with isolated location, by a triode and a resistance, formed, by the base stage of penetrating with triode in isolated location, the output terminal that has connected the preposition unit of bridge type, penetrate with the collector of isolated location triode and connect power supply, emitter has been connected after a resistance as penetrating the output terminal with isolated location.

Amplifying unit, by first NPN triode and second PNP triode, jointly formed, with first transistor base, connect and penetrate the output terminal with isolated location, grounded emitter, collector has been connected and has been connected the base stage of second triode after a resistance, the emitter of second triode connects power supply, and collector is as output terminal at the corresponding levels; This output terminal has connected onsite alarming unit.

The one end that has connected touch sheet with a wires, the other end has been connected to have connected after an electric capacity and in the preposition unit of bridge type, has been connected two utmost point positive terminals.

Onsite alarming unit is the base stage that the output of voice sheet has connected preposition amplifier tube, the grounded emitter of preposition amplifier tube, collector is connected in the base stage of the PNP pipe that forms power amplifier, the base stage that forms the PNP pipe of power amplifier has also connect one end of power amplifier level pull-up resistor, the pull-up resistor other end connects to form the base stage of the NPN pipe of power amplifier, the PNP pipe that forms power amplifier manages with NPN the commissure electric capacity of central point series winding that emitter is connected, one end of another termination loudspeaker of commissure electric capacity, the other end ground wire of loudspeaker, the NPN pipe Integrated electrode that forms power amplifier is received on the electronic switch of shooting with video-corder control module.

2,4 capacitance parameters that connect in the preposition unit of bridge type are consistent, and adopt high-tension electric capacity.

3, touch sheet is mounted in the shop front of antitheft door, and the lockhole on door is covered together with lockhole switch.

4, lockhole switch is travel switch.

What 5, in onsite alarming, loudspeaker were selected is internal magnetization loudspeaker.

What 6, in onsite alarming, form that the triode of power amplifier selects is large power triode.

For having a clear understanding of the meaning of the technical program, first will make the following instructions:

It one is that normal door is opened the door without mechanical key that inventor has been fruitful, but the mode of opening the door with electronics telecontrol engineering or phone.When normal door, be installed on the propulsion system in door, will promote lockset action, realization is opened the door.Meanwhile, still retained the form that mechanical key opens the door, its objective is and when automatic system goes wrong, can have a kind of opening the door to make up.This be if opened the door with mechanical key, and great majority are to want by joining the situation of mechanical key crime, are also the situations that needs telephone call.And a few cases is own oneself to want the situation of opening the door with mechanical key because electrical equipment goes wrong, but this situation is own clearly situation on the scene, produces alert sound oneself and does not also feel fearful and nervous.

Have identification circuit, can correctly identify is the situation of crime behavior or owner's normal door.Its reason is that the behavior of opening the door is normally to open the door by electronic technology, rather than opens the door with mechanical key.When normal method is used electronic open-door, identification circuit input has electronic signal, and the input of crime behavior identification circuit is without electronic signal, will start warning system.

For this reason, the existing meaning to each technical measures of the present invention, concrete condition is further explained as follows:

One, the present invention design is that a kind of band has levels and has the alarming device of several functions.

(1). the first level is pre-warning: fundamental purpose is to prevent the heart that has crime, or firm crowd when bud.Function is to rigidly connect and touch above lockhole after cover plate at the hand when crime, sound system will send pre-warning, this warning is more neutral, as the sound can send " please noting ", or the language such as " please not staying at this " is prevented, by the benefit of gender neutral language, be to may criminal causing very large psychological pressure, but can not damage being not intended to person, to neighbours, more can not cause in terror, because causing consequence, pre-warning and crime also have very large gap, can produce so very large benefit, be to produce pressure very greatly at heart to criminal, the generation of pre-warning can make him know clearly, in room, early there is preparation, if continued, must there is " below " waiting for, by have thereby hint obliquely at later difficult, probably impel it to stop as early as possible, halt at this point, so played the initiatively effect of protection.

(2), the protection of the second level is warning device; mainly the criminal for the pre-warning of not preventing, if think formal damage lock port lid, while entering house by cracking lockhole; to be subjected to displacement by the shift knob of lockhole cap lower compression, and send formal warning enabling signal.

Electronic self-locking circuit has been used in the startup of reporting to the police, and its benefit one is the requirement of having relaxed switch, is that switch can be key type, also can be button-type, and on the power of contact without impact, so can adopt miniature, the difficulty of installing to reduce switch increases the attractive in appearance of door simultaneously.The 2nd, improved sensitivity and the reliability of the starting of reporting to the police.Because principle of the present invention is, when its people has when cracking lockhole or having the action that barbarous mode forces open the door, alarming starter action, sends warning initiating signal, and electronic timing formula on-off circuit starts immediately, sends initiating signal.

One of (1) form that pipe is amplified that adopts NPN and PNP to constitute jointly, has following meaning,, amplification quantity is large; Two, PNP amplifying triode become saturated after, the loss of voltage little (when being furnished with accumulator, peculiar meaning) of generation; Three, can easily transient signal be changed into a kind of long signal; Four, formed electronic switch volume urine is in miniaturization.

(2), in the electronic switching circuit that pipe is formed, anti-remaining resistance, be that the resistance connecing between PNP amplifying triode emitter and base stage has played vital role in circuit, its effect is when NPN amplifying triode no signal, the thorough no-voltage of output of switch, output, without any remaining electricity, for the through engineering approaches that electronic switch uses, has been created essential condition.

(3), why between two pipes, add the positive feedback with Capacitance derivative, the one, meet this condition, the 2nd, can realize automatic recovery.

Two. principle and effect that pre-warning produces:

1, touch principle: when no touch signal, the bridge diagram no-output that four electric capacity in communication channel form, the preposition unit of bridge type, no-output.When having touch signal, the bridge diagram parameter generation great change that former four electric capacity form, there is alternating current output, through after diode is the rectification circuit that forms of the rectifier cell (11 in Fig. 1) in electric bridge, there is direct current output, through penetrating with isolated location, after amplifying unit amplifies, finally encourage onsite alarming unit, thereby produced the various effects that various functional units produce.

2, circuit is outstanding reliable: sensitive reliable.

(1), the preposition unit of bridge type, performance is good: its reason is when no touch signal, 4 electric capacity (07 in Fig. 1,08,09,10) parameter of electric bridge is consistent, internal current balance, the output of bridge-type output terminal no signal, after hand contact chip, there is serious variation in the capacitance parameter that contains touch sheet end, so output terminal has signal output, bridge diagram and bridge rectifier circuit all belong to classical circuit in circuit, theoretical show with test, and this circuit has very high sensitivity, and circuit is very reliable and stable, for the present invention has established fine basis.

(2), isolated location played matching effect well between the preposition unit of bridge type and amplifier stage, further promoted the performance of measure of the present invention.This grade of the first has very high input impedance, played good buffer action in two-stage.It two is that output impedance is low, and the excitation of rear class is had to very strong surplus.

(3), amplifier stage has outstanding performance.First NPN triode of this grade of the first is that the door of first triode (14 in Fig. 1) input in amplifying unit is very low, only has 0.7 volt.Two is that second PNP triode is that in amplifying unit, second triode (16 in Fig. 1) has very strong amplifying power, because first triode in amplifying unit (14 in Fig. 1) has formed complementary relationship with second triode (16 in Fig. 1) in amplifying unit, the 3rd, second triode (16 in Fig. 1) in amplifying unit has very strong carrying load ability, formed the form of electronic switch.

(4) it is that operating voltage can have relatively wide scope that, in the present invention active all adopts the benefit of triodes, thereby can save mu balanced circuit in working power, and its benefit has two, the first, and circuit simplifies, more reliable.The secondth, if while adopting three end contain integrated regulator, when civil power changes when too high, fragile.

(5), when no touch signal, system power saving has also reduced having " electrical wear " of element, the reliability of having promoted circuit from another angle simultaneously.

The lockhole switch of three, pacifying in measure scheme one, it is the key component that warning of the present invention starts, also be a bright spot of putting of the present invention, because after the existing achievement of this part and inventor cooperatively interacts, warning of the present invention has been accomplished more scientific, also be the place different from a lot of alarms, its reason is:

The one, can generation not make us terrified wrong report, this is the most important.Its reason is, the door that owner is absent from the scene is within doors opened (with improper, opening), or opens the door by lockhole with ' key ', is all crime behaviors, and warning is now all very significant.

The 2nd, very reliable, because the opening the door at closing time of normal life, do not need artificial additional move, do not affect the normal habits and customs of people, thereby do not affect the normal operation of the each starting of security system.

The 3rd, warning starting switch is sensitive and reliable, can when crime behavior is not accomplished, just not report to the police, thereby loss is reduced to minimum.The initiating signal of reporting to the police because the switch contact when lockhole cap is becoming flexible on lockhole will change.

Four, in onsite alarming, by a triode, formed the prestage that sound equipment amplifies, by a PNP pipe that forms power amplifier, formed complementary circuit with the NPN pipe that forms power amplifier audio frequency has been carried out to power amplifier, when having pre-alarm signal, the power supply of having opened this part is controlled in its output, so have voice to produce, due to this electric circuit constitute be an OTL rather than OCL circuit, so debugging is simple, and have element not perishable, and the higher advantage of efficiency.

After the invention process, anti-theft security goalkeeper presents a kind of brand-new looks, has following outstanding advantage:

1, after the invention process; anti-theft safety door and alarm have been realized the combination of science; the advantage that has possessed two kinds of protectors; usually both people can be kept outside the door; when running into other people and committing a crime; can send two kinds of warnings; to increasing " the initiatively protectiveness " of anti-theft safety door; (its implication is; function of the present invention will suppress crime behavior generation; and whether waiting for passively that it destroys) and be all very significant, the situation of the passive defence of anti-theft safety door so this product is through with completely, has promoted security personnel's performance of anti-theft safety door all sidedly.

2, Forewarning Measures performance is outstanding reliable, can guarantee this functional effect.Reason one is highly sensitive, can guarantee that early warning system will be started immediately when having people to want to destroy lockhole.The 2nd, load capacity is strong, thereby various effect can fully demonstrate, and the 3rd, circuit is reliable, not fragile.

3, warning system partial properties is very excellent, for alarm, is most valuable, embodies in the following areas:

The one, warning system can not reported by mistake completely.Because after coordinating with existing achievement, there is automatic recognition property.The warning producing when owner is absent from the scene may be only crime behavior.Otherwise the behavior of not committing a crime, switch can not send signal, at this moment because the structures shape of switch is installed.Due to the intrinsic property of switch, when being subject to compressing and not suffering oppression, shift knob there is to occur the variation of contact.

The 2nd, reliable, its reason one is, user is closing the door when opening without any need for other additional move, thereby warning system is at any time all in a kind of " highly waiting " state, do not need any preliminary work, the 2nd, the malfunctioning chance of mechanical switch is far superior to electronic component.

The 3rd, easy to use.After installation, do not affect normal habits and customs completely.If increased trouble with former life, the shortcoming of obviously bringing to people is or is to use inconvenience, or forgotten necessary operation and bring the malfunction of warning or malfunctioning.

The 4th, protection is tight, has laid special stress on protecting the practice that cracks lockhole.

The 5th, relaxed the requirement to switch, reduce the difficulty that switch is installed, the reliable and confidence level that having improved reports to the police starts.

Accompanying drawing explanation

Fig. 1 is that electric bridge of the present invention is warned basic diagram in advance.

In figure: 01, the primary side of transformer; 02, the out secondary of transformer; 03, full-wave rectification diode; 04, rectifying and wave-filtering electric capacity; 05, touch sheet; 06, commissure electric capacity; 07, the electric capacity in electric bridge one; 08, the electric capacity in electric bridge two; 09, the electric capacity in electric bridge three; 10, the electric capacity in electric bridge four; 11, the rectifier cell in electric bridge; 12, penetrate with isolated location; 13, protective resistance; 14, first triode in amplifying unit; 15, the commissure resistance of two triodes in amplifier stage; 16, second triode in amplifying unit; 17, bridge type early warning amplifying unit output.

Fig. 2 is the scheme of installation of touch sheet and lockhole switch.

In figure: 05, touch sheet; 390, lockhole; 391, the printed panel of welding lockhole switch; 392, the fixing screw of touch sheet; 393, lockhole switch; 395, lockhole switch extension line; 397, anti-theft safety door.

Fig. 3 is electronic self-locking circuit figure.

In figure: 395, lockhole switch extension line; 52, input resistance; 53, NPN amplifying triode; 54, commissure resistance; 55, the resistance of sealing up a door; 56, PNP amplifying triode; 57, isolating diode; 58, put remaining resistance; 59, feedback capacity; 60, discharge resistance; 61, feedback resistance; 62 feedback diodes; 63, steady resistance; 71, the electrochemical capacitor that forms electrodeless electric capacity; 75, electronic self-locking circuit output.

Fig. 4 is onsite alarming circuit diagram.

In figure: 17, bridge type early warning amplifying unit output; 75, timing feedback output; 301, neutral voice sheet; 302, preposition amplifier tube; 303, preamplifier state load dual-use function resistance; 304, the PNP pipe that forms power amplifier; 305, the NPN pipe that forms power amplifier; 306, commissure electric capacity (OTL circuit capacitance); 308, loudspeaker.

Fig. 5 is that each several part is related to block diagram.

In figure: 05, touch sheet; 290, the pre-warning circuit of electric bridge; 393, lockhole switch; 256, electronic self-locking circuit; 291, onsite alarming unit.

Embodiment

Fig. 1,2,3,4,5 has described specific embodiment of the invention example.

One, according to Fig. 3 embodiment, the cover plate of covering lockhole being installed, is also touch sheet and the lockhole switch in indication function.

1, with a hard material, be processed into and strike out the touch sheet larger than lockhole, touch sheet is also to cover the cover plate of lockhole.

2, the periphery in touch sheet (cover plate) spiles, and the place punching that cover plate is installed at shop front lockhole is corresponding with it, the mounting hole tapping of the shop front.

4, between touch sheet and door, add hollow cushion ring, allow hollow place expose lockhole.

5, touch sheet is fixed in the shop front.Fixedly time, should notice between touch sheet and door fixedly time that pad last layer insulant is as plastic washer.

6, with one end of a wire, connect touch sheet, the other end has connected the electric bridge being positioned in door and has warned in electronic circuit in advance.

7, lockhole switch is welded on a bar printing plate, the printed panel that has welded switch is fixed on door lock hole.

8, lockhole switch contact is drawn the input that has connected timing feedback circuit with wire.

9, touch sheet is oppressed lockhole shift knob after fixing.

10, the enforcement of electronic self-locking circuit is pressed shown in Fig. 3, adjusts feedback capacity and feedback resistance, allows feedback time meet the requirements.

Two, installation and debugging electronic circuit;

1, selectors; The preposition unit of bridge type electric capacity used adopts withstand voltage high electric capacity kind.Bridge diode in electric bridge also should select the kind that back-pressure grade is high.Onsite alarming unit can be selected one, or two, or a plurality of etc., can be selected by the requirement of oneself, as onsite alarming, telephone call, automatic camera etc. function.

2, welding: weld according to Fig. 1.

3, debugging:

(1), test and the adjustment preposition unit of bridge type: with the voltage gear of multimeter, survey and penetrate penetrating with output with triode in isolated location, when contacting when coverage sheet on lockhole is touch sheet, do not penetrate with being output as low level with device in hand, below 0.5 volt, and integrated circuit the 2nd pin should be exported a high position when hand contacts the coverage sheet on lockhole, whether equally the nonconforming emphasis of answering changes four capacitance values of electric bridge, if desired, the capacity inspection of available electric bridge to four electric capacity, whether the same referring to seeing number.

Test with adjust amplifier stage unit: second transistor emitter in the use voltage detecting amplifying unit of multimeter and the voltage between collector, when prestage integrated circuit no-output, voltage should be supply voltage substantially, and while having touch signal, voltage should be less than 0.5 volt nonconformingly should adjust the commissure resistance between two triodes in this grade.

Three, the enforcement of onsite alarming unit: weld audio amplification circuit by shown in Fig. 4, electric bridge early warning is amplified to output and be connected respectively in audio amplification circuit with the output of electronic self-locking circuit.

Four, Detection and adjustment onsite alarming unit effect:

When hand contact touch sheet, on-the-spot early warning should be sent early warning sound, and when hand leaves touch sheet, corresponding function should stop, otherwise should adjust the adjustment part in corresponding unit.

Claims

1. household electric bridge-type alarm, is characterized in that: by touch sheet, and electric bridge prewarning unit, warning start unit, onsite alarming unit forms jointly;

Warning start unit is comprised of lockhole switch and electronic self-locking circuit:

Lockhole switch is arranged on lockhole top, touch sheet below, and touch sheet is oppressed the button of lockhole switch after being fixed on door, and lockhole switch contact is drawn with wire, connecting electronic latching circuit;

Electronic self-locking circuit is: with lockhole switch contact extension line, connect the base stage of a NPN amplifying triode after the series connection of input resistance, the grounded emitter line of NPN amplifying triode, one end of steady resistance connects the base stage of NPN amplifying triode, other end ground wire; The base stage of the rear connection PNP amplifying triode of a commissure resistance of collector series connection of NPN amplifying triode, the emitter of PNP amplifying triode connects 12 volts of power supplys, and the resistance of sealing up a door is connected between the emitter and collector of PNP amplifying triode; Isolating diode positive pole is connected on the collector of PNP amplifying triode, negative pole is connected on one of feedback capacity and extremely goes up, the negative pole of isolating diode has also connect over the ground one and has put remaining resistance, is connected to the base stage of NPN amplifying triode after another utmost point serial Feedback resistance of feedback capacity and feedback diode; Another utmost point of this electric capacity has also connect a discharge resistance over the ground, and PNP amplifying triode collector is connected in onsite alarming unit;

Bridge type prewarning unit by transformer unit, the preposition unit of bridge type, penetrate with isolated location, amplifying unit and form;

With transformer unit, connected the preposition unit of bridge type, the preposition unit of bridge type has connected to be penetrated with isolated location, penetrates with isolated location and has connected amplifying unit, and amplifying unit has connected onsite alarming unit; With the wires touch sheet sheet metal of ining succession, the other end of this metal wire has connected the preposition unit of bridge type after having connected a commissure electric capacity;

The connection of transformer unit is; The positive pole that connects respectively two diodes with the secondary two ends of transformation, secondary central shaft heads ground connection, has connected two-way after the negative pole of two diodes links together, and the first via has connected working power, the second tunnel has connected the positive pole of an electric capacity, the minus earth of this electric capacity;

The preposition unit of bridge type is that rectifier cell in electric bridge and the electric capacity in electric bridge form; Two diodes of the rectifier cell in electric bridge are composed in series a new branch road, and two diode series connection points become the outside output terminal of the preposition unit of bridge type; Another two diodes are composed in series another new branch road, and its series connection point connects ground wire; The positive pole of two new branch roads links together, and becomes bridge rectifier circuit positive pole, and negative pole connects together, as the negative pole of bridge rectifier circuit;

With the electric capacity one in electric bridge, be connected the positive terminal of rectification circuit with one end of electric capacity two in electric bridge, the other end of the electric capacity one in electric bridge has connected one end of primary, and the other end of the electric capacity two in electric bridge has connected the other end of primary; Electric capacity three in bridge rectifier circuit negative pole connection electric bridge and one end of the electric capacity four in electric bridge, the electric capacity three elementary one end of other end connection transformer in electric bridge, the other end of the electric capacity four in electric bridge has connected the other end of primary;

Penetrate with isolated location, by a triode and a resistance, formed, by the base stage of penetrating with triode in isolated location, the output terminal that has connected the preposition unit of bridge type, penetrate with the collector of isolated location triode and connect power supply, emitter has been connected after a resistance as penetrating the output terminal with isolated location;

Amplifying unit, by first NPN triode and second PNP triode, jointly formed, with first transistor base, connect and penetrate the output terminal with isolated location, grounded emitter, collector has been connected and has been connected the base stage of second triode after a resistance, the emitter of second triode connects power supply, and collector is as output terminal at the corresponding levels; This output terminal has connected onsite alarming unit;

The one end that has connected touch sheet with a wires, the other end has been connected to have connected after an electric capacity and in the preposition unit of bridge type, has been connected two utmost point positive terminals;

2. household electric bridge-type alarm according to claim 1, is characterized in that: 4 capacitance parameters that connect in the preposition unit of bridge type are consistent, and adopt high-tension electric capacity.

3. household electric bridge-type alarm according to claim 1, is characterized in that: touch sheet is mounted in the shop front of antitheft door, and the lockhole on door is covered together with lockhole switch.

4. household electric bridge-type alarm according to claim 1, is characterized in that: lockhole switch is travel switch.

5. household electric bridge-type alarm according to claim 1, is characterized in that: what in onsite alarming, loudspeaker were selected is internal magnetization loudspeaker.

6. household electric bridge-type alarm according to claim 1, is characterized in that: what in onsite alarming, form that the triode of power amplifier selects is large power triode.