CN100373731C - Lightningproof circuit and immersion type piezoresistance liquid level transmitter with the same - Google Patents
Lightningproof circuit and immersion type piezoresistance liquid level transmitter with the same Download PDFInfo
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- CN100373731C CN100373731C CNB2005100379803A CN200510037980A CN100373731C CN 100373731 C CN100373731 C CN 100373731C CN B2005100379803 A CNB2005100379803 A CN B2005100379803A CN 200510037980 A CN200510037980 A CN 200510037980A CN 100373731 C CN100373731 C CN 100373731C
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Abstract
The present invention relates to an immersion type pressure resistance liquid level transmitter with a lightning protection circuit, which is composed of a pressure resistance sensitive component, a transmitter, a transmitter casing and an air guiding balanced cable, wherein the pressure resistance sensitive component is formed by isolating and soaking a stainless steel corrugation film into a silicon pressure resistance sensitive component in silicon oil, and the stainless steel corrugation film is used as a compression face which transmits the pressure to the silicon pressure resistance sensitive component. The back pressure side of the pressure resistance sensitive component and the transmitter casing are sealed in a waterproof way, and the air guiding balanced cable and the transmitter casing are sealed in the waterproof way. The silicon pressure resistance sensitive component is communicated with the external atmospheric pressure by using an air guiding pipe in the air guiding balanced cable. The lightning protection circuit is connected between an input line and an output line of the transmitter, and the lightning protection circuit is sealed on a lightning protection circuit board in a stainless steel casing. The stainless steel casing and the transmitter casing are sealed in the waterproof way, and the lightning protection circuit and the transmitter casing are connected to the ground. The present invention has the characteristics of large lightning protection energy, quick response time, less residual voltage and residual current, low clamp on voltage, small packaging size of the liquid level transmitter, etc.
Description
Technical field
The present invention relates to a kind of lightning protection circuit and have the throw-in type piezoresistance liquid level transmitter of lightning protection circuit, be particularly related to a kind of throw-in type piezoresistance liquid level transmitter that has the lightning protection circuit of strong anti-thunderbolt and have lightning protection circuit, be applied to that spaciousness, a high position are subject to be struck by lightning, the application scenario of long outgoing cable and pressure liquid level transmitter palpus microencapsulated.
Background technology
The lightning protection and the anti-surge protection circuit main method that now are applied to power supply and electric prospection have:
1. between power supply and holding wire and connect piezo-resistance or the TVS pipe is protected, this kind guard method is simple but surge impact energy that can protect is less;
2. between power supply and signal and connect potent lightning protection discharge tube and protect, the surge impact energy that this kind guard method can be protected is bigger, but residual voltage is bigger, causes the damage of transmitter integrated circuit easily;
3. adopt the anti-lightning strike and surge power supply protector of board plug type to protect, its protective capability is better, but external form is not suitable for the pressure liquid level transmitter of compact size more greatly.
Summary of the invention
In order to remedy above deficiency, a kind of lightning protection circuit provided by the invention has characteristics such as protection thunderbolt energy is big, the reaction time fast, the residual voltage residual flow is little, strangulation voltage is low and have this lightning protection circuit throw-in type piezoresistance liquid level transmitter package dimension is little.
Technical scheme of the present invention is achieved in that
A kind of lightning protection circuit is connected between the incoming line and output line of transmitter, and this lightning protection circuit is made up of three grades of circuit, wherein:
First order circuit is by three gas discharge tubes and first resistance, second resistance, first inductance, second inductance constitutes, a cross-over connection in these three gas discharge tubes is between this transmitter incoming line and output line, in addition two gas discharge tubes be connected across respectively the incoming line of this transmitter and output line over the ground between, these three gas discharge tubes have the bleed off electric energy power of 10KA and less than reaction time of 1us, first resistance and first inductance, second resistance and second inductance are serially connected in the incoming line of this transmitter respectively, constitute first order time delay circuit on the output line to next stage bleed off electricity;
Second level circuit is made of three solid discharging tubes and the 3rd inductance and the 4th inductance, in these three solid discharging tubes one be connected across this transmitter incoming line through first contact behind first resistance, first inductance and this transmitter output line through between second contact of first resistance, second inductance, two other solid discharging tube is connected across respectively between first contact, second contact and the ground, these three solid discharging tubes have≤reaction time of 10nS, and the 3rd inductance and the 4th inductance constitute respectively to the second level of next stage vent discharge time delay circuit;
Tertiary circuit is made of three Transient Suppression Diodes and first resettable fuse and second resettable fuse, one in these three Transient Suppression Diodes is connected across this transmitter incoming line through first resistance, first inductance, the 3rd contact behind the 3rd inductance and this transmitter output line are through second resistance, second inductance, between the 4th contact behind the 4th inductance, two other transient state diode is connected across the 3rd contact respectively, between the 4th contact and the ground, these three Transient Suppression Diodes have≤reaction time of 1ns, and the clamping voltage of these three Transient Suppression Diodes is lower than the maximal work voltage of this transmitter.
As a further improvement on the present invention, this lightning protection circuit satisfies the reaction time: gas discharge tube〉solid discharging tube〉Transient Suppression Diode; Shock resistance energy: gas discharge tube〉solid discharging tube〉Transient Suppression Diode; Clamping voltage: gas discharge tube〉solid discharging tube〉Transient Suppression Diode.
A kind of throw-in type piezoresistance liquid level transmitter that comprises that described lightning protection circuit is formed, by the quick assembly of liquid level pressure resistance, transmitter, transmitter housing and air guide balanced cable are formed, the quick assembly of this pressure resistance is isolated by stainless steel ripple film that the silicon pressure resistance photosensitive elements be soaked in the silicone oil forms, and give this silicon pressure resistance photosensitive elements as the compression face pressure transmission with this stainless steel ripple film, the signal of drawing of this silicon pressure resistance photosensitive elements is exported by output cable after this transmitter amplifies, realize waterproof sealing based on side arm zero type circle between the back pressure side of the quick assembly of this pressure resistance and this transmitter housing, realize waterproof sealing between this air guide balanced cable and this transmitter housing, realize this silicon pressure resistance photosensitive elements and the atmospheric communication balance of external environment by the wireway in this air guide balanced cable, this lightning protection circuit is connected between the input-output line of transmitter, the packed lightning protection circuit plate that is fixed in the Stainless Steel Shell that external diameter is φ 24mm～φ 40mm of this lightning protection circuit, realize waterproof sealing between this Stainless Steel Shell and this transmitter housing, this lightning protection circuit connects this transmitter shell and is grounded.
As a further improvement on the present invention, the affixed anti-drift of compression face one end of the quick assembly of this pressure resistance, and realize that by the water inlet on this anti-drift the compression face of the quick assembly of this pressure resistance is communicated with extraneous liquid phase, thus realize the impression of fluid pressure to external world.
As a further improvement on the present invention, this water inlet adopts the double-T shaped hole with minimizing fluid dynamics effects to disappear dynamic pressure diversion header structure to adapt to quick circulating water application operating mode.
As a further improvement on the present invention, this water inlet adopts the ring-like hole with minimizing fluid dynamics effects to disappear dynamic pressure diversion header structure to adapt to circulating water application operating mode at a slow speed.
As a further improvement on the present invention, this air guide balanced cable, shielding conductor by cable sheath, internal core wire and wrapped this internal core wire is formed, this cable sheath is made by polyethylene, polyvinyl chloride or the Polyurethane plastics of anti-water insulation, this internal core wire is that the wireway of material is formed by cable tail with polypropylene or polytetrafluoroethylene, thick zero type circle extruding realizes waterproof sealing based on silicon rubber between this air guide balanced cable and this transmitter housing, this cable lead division is coated with the nitrile rubber wire bushing simultaneously, and with line ball emit be rotated with realize in this transmitter housing afterbody fixing.
As a further improvement on the present invention, this transmitter is the two-wire system liquid level transmission circuit of 4-20mA output signal, adopts the XTR101 circuit of anti-overcurrent and mistake pressure, has 40V maximal work voltage, and the clamping voltage of this Transient Suppression Diode is 36V.
The invention has the beneficial effects as follows:
The ground connection of this lightning protection circuit is connected well with the shell of this transmitter, it is the main channel of thunderbolt induced current bleed off, the first order circuit of this lightning protection circuit has the bleed off electric energy power of 10KA and less than reaction time of 1uS, this first order time delay circuit plays certain time-lag action to surge impact voltage and electric current, and most surge impact energy is discharged in first order discharge tube; Second level circuit has the faster bleed off electricity reaction time for 10nS, and second level time delay circuit constitutes the time delay to third level vent discharge, thereby induction residual voltage and residual flow that the third level is born are almost nil; And the Transient Suppression Diode in the tertiary circuit has the reaction time of 1nS; even thereby the high-frequency induction residual voltage or the electric current that have prime to have little time to release; it has also guaranteed releasing of impact energy; its reaction time and transmitter instrument amplifier circuit are at the same order of magnitude; thereby guaranteed its realization as the purpose of afterbody insurance; resettable fuse is provided with for cooperating residual releasing; transmitter circuit input impedance along separate routes when being intended to strengthen residual flow; assurance is gone up the residual flow of releasing from TVS1 more; after the process protection of the third level; make protection voltage clamping to the integrated circuit of back in 36V; almost do not have impulse current, thereby integrated circuit is played a protective role.
This lightning protection circuit is packed to be fixed in lightning protection circuit plate in the metal-back of certain external diameter, thereby is not only applicable to freely throw in, also is applicable to prevent silt become silted up storehouse, the dam of installation in the pipe that buries, the little external diameter requirement of river level measurement.
This fluid level transmitter utilizes the Principles of Statics measuring liquid level, learns effect accuracy of measurement is influenced for reducing flow dynamic, uses operating mode for quick floating-channel water, and the good double-T shaped hole of the dynamic pressure effect that the disappears dynamic pressure diversion head that disappears has been adopted in this water inlet; Use operating mode for circulating water at a slow speed, this water inlet has adopted the dynamic pressure effect that disappears general, but the sand prevention blockage effect ring-like hole of the turbulent model dynamic pressure diversion head that disappears preferably.
Description of drawings
Fig. 1 is lightning protection circuit figure of the present invention;
Fig. 2 is the structural representation of air guide balanced cable of the present invention;
Fig. 3 is a fluid level transmitter XTR101 circuit diagram of the present invention;
Fig. 4 is the structural representation of throw-in type fluid level transmitter of the present invention.
Specific embodiment
Be further described below in conjunction with Fig. 1 to Fig. 4:
A kind of lightning protection circuit is connected between the incoming line and output line of transmitter, and this lightning protection circuit is made up of three grades of circuit, wherein:
First order circuit is by three gas discharge tube U1, U2 and U3 and first resistance R 1, second resistance R 2, first inductance L 1, second inductance L 2 constitutes, a cross-over connection in these three gas discharge tubes is between this transmitter incoming line and output line, in addition two gas discharge tubes be connected across respectively the incoming line of this transmitter and output line over the ground between, these three gas discharge tubes have the bleed off electric energy power of 10KA and less than reaction time of 1us, first resistance R 1 and first inductance L 1, second resistance R 2 and second inductance L 2 are serially connected in the incoming line of this transmitter respectively, constitute first order time delay circuit on the output line to next stage bleed off electricity;
Second level circuit is by three solid discharging tube U4, U5 and U6 and the 3rd inductance L 3 and the 4th inductance L 4 constitute, one in these three solid discharging tubes is connected across this transmitter incoming line through first resistance R 1, first contact after first inductance L 1 and this transmitter output line are through second resistance R 2, between second contact of second inductance L 2, two other solid discharging tube is connected across first contact respectively, between second contact and the ground, these three solid discharging tubes have≤reaction time of 10nS, and the 3rd inductance L 3 and the 4th inductance L 4 constitute respectively to the second level of next stage vent discharge time delay circuit;
Tertiary circuit is by three Transient Suppression Diode TVS1, TVS2 and TVS3 and the first resettable fuse F1 and the second resettable fuse F2 constitute, one in these three Transient Suppression Diodes is connected across this transmitter incoming line through first resistance R 1, first inductance L 1, the 3rd contact after the 3rd inductance L 3 and this transmitter output line are through second resistance R 2, second inductance L 2, between the 4th contact after the 4th inductance L 4, two other transient state diode is connected across the 3rd contact respectively, between the 4th contact and the ground, these three Transient Suppression Diodes have≤reaction time of 1ns, and the clamping voltage of these three Transient Suppression Diodes is lower than the maximal work voltage of this transmitter.
This lightning protection circuit satisfies the reaction time: gas discharge tube〉solid discharging tube〉Transient Suppression Diode; Shock resistance energy: gas discharge tube〉solid discharging tube〉Transient Suppression Diode; Clamping voltage: gas discharge tube〉solid discharging tube〉Transient Suppression Diode.
A kind of throw-in type piezoresistance liquid level transmitter that comprises that described lightning protection circuit is formed, by the quick assembly 2 of liquid level pressure resistance, transmitter 6, transmitter housing 7 and air guide balanced cable 20 are formed, the quick assembly of this pressure resistance is isolated by stainless steel ripple film that the silicon pressure resistance photosensitive elements be soaked in the silicone oil forms, and give this silicon pressure resistance photosensitive elements as the compression face pressure transmission with this stainless steel ripple film, the signal of drawing of this silicon pressure resistance photosensitive elements is exported by output cable after this transmitter amplifies, realize waterproof sealing based on side arm zero type circle 3 between the back pressure side of the quick assembly of this pressure resistance and this transmitter housing, realize waterproof sealing between this air guide balanced cable and this transmitter housing, realize this silicon pressure resistance photosensitive elements and the atmospheric communication balance of external environment by the wireway in this air guide balanced cable, this lightning protection circuit is connected between the input-output line of transmitter, the packed lightning protection circuit plate 11 that is fixed in the Stainless Steel Shell 10 that external diameter is φ 24mm～φ 40mm of this lightning protection circuit, realize waterproof sealing between this Stainless Steel Shell and this transmitter housing, this lightning protection circuit connects this transmitter shell and is grounded.
The affixed anti-drift of compression face one end of the quick assembly of this pressure resistance, and realize that by the water inlet on this anti-drift the compression face of the quick assembly of this pressure resistance is communicated with extraneous liquid phase, thus realize the impression of fluid pressure to external world.This water inlet employing has the double-T shaped hole of reducing the fluid dynamics effects and disappears dynamic pressure diversion header structure to adapt to quick circulating water application operating mode, and perhaps this water inlet adopts the ring-like hole with minimizing fluid dynamics effects to disappear dynamic pressure diversion header structure to adapt to circulating water application operating mode at a slow speed.
This air guide balanced cable, shielding conductor 14 by cable sheath 21, internal core wire and wrapped this internal core wire is formed, this cable sheath is made by polyethylene, polyvinyl chloride or the Polyurethane plastics of anti-water insulation, this internal core wire is that the wireway 13 of material is formed by cable tail 12 with polypropylene or polytetrafluoroethylene, 16 extruding realize waterproof sealing based on the thick zero type circle of silicon rubber between this air guide balanced cable and this transmitter housing, this cable lead division is coated with nitrile rubber wire bushing 19 simultaneously, and with line ball emit 18 be rotated with realize in this transmitter housing afterbody fixing.
This transmitter is the two-wire system liquid level transmission circuit of 4-20mA output signal, adopts the XTR101 circuit of anti-overcurrent and mistake pressure, has 40V maximal work voltage, and the clamping voltage of this Transient Suppression Diode is 36V.
The operating mode that the throw-in type piezoresistance liquid level transmitter in use often has is spacious; a high position is subject to thunderbolt; its long cable that reaches tens of rice even surpass hundred meters also very easily induction lightening cause transmitter circuit even transducer damage; general shocking preventing technology and lightning protection component size are too big; can't pack in the transmitter housing thereby inapplicable; and the residual voltage residual flow is big; be not suitable for protection precision instrument integrated circuit yet; therefore the present invention utilizes different discharge tube characteristics under the prerequisite of miniaturization; coupling corresponding protection circuit; to since the surge voltage that cable conduction enters of passing through that lightning induction causes protect and voltage clamping, thereby avoid the destruction of surge voltage to transmitter circuit and transducer.
Lightning protection circuit of the present invention is made up of three grades of circuit: first order circuit has the bleed off electric energy power of 10KA and less than reaction time of 1uS, most surge impact energy is discharged in first order discharge tube, guaranteed that first order bleed off reaches 70% ~ 80% of induction electric weight; In the bleed off electricity reaction time of second level circuit≤10nS, guarantee that the second level amount of releasing reaches the 20%-30% of induction electric weight, thereby induction residual voltage and residual flow that the third level is born are almost nil; Tertiary circuit has≤reaction time of 1nS; and with this transmitter instrument amplifier circuit at the same order of magnitude; thereby guaranteed its realization as the purpose of afterbody insurance; resettable fuse is provided with for cooperating residual releasing; transmitter circuit input impedance along separate routes when being intended to strengthen residual flow; assurance is gone up the residual flow of releasing from TVS1 more; after the process protection of the third level; make protection voltage clamping to the integrated circuit of back in 36V; almost do not have impulse current, thereby integrated circuit is played a protective role.
Properties of product test of the present invention
The invention test agent is pressed GB/T 17626.5-1999 surge impact immunity experiment standard, pressed the poorest 3-5 class installation environment by testpieces, test severity grade is pressed the highest 3 grades and 4 grades, follows the inferior complex wave surge impact test of having carried out 2KV/1KA, 4KV/2KA;
Three red lines to shielding conductor, three blue lines to the complex wave shock-testing of shielding conductor, three red lines to the 2KV/1KA of blue line;
(＜1 minute, the power supply 24VDC) detection of switching on immediately after the test is normal by the test specimen output current, is the preceding output current of test, current changing rate＜0.05%FS;
Three red lines to shielding conductor, three blue lines to the complex wave shock-testing of shielding conductor, three red lines to the 4KV/2KA of blue line;
(＜1 minute, the power supply 24VDC) detection of switching on immediately after the test is normal by the test specimen output current, is the preceding output current of test, current changing rate＜0.05%FS;
After test finishes, carried out the test of shock resistance ultimate strength with reference to multiple power source lightning protection device concerned countries standard:
Experimental condition 10KV/5KA, sample is by test, and output current is normal;
Experimental condition 20KV/10KA, after the sampling test, the no-output electric current checks that lightning protection component is normal, source of damage system inserts between electrode because of the big inadequately dielectric strength of size small distance is not enough, the electrode punch through damage.
Result of the test shows that originally strong anti-thunderbolt throw-in type piezoresistance liquid level transmitter has surge impact ability of extremely strong strong anti lightning induction, and the energy Secure Application is in thunderbolt is frequent, lightning induction is strong southern river and northern high mountain measuring point operating mode.
Claims (8)
1. a lightning protection circuit is connected between the incoming line and output line of transmitter, it is characterized in that, this lightning protection circuit is made up of three grades of circuit, wherein:
First order circuit is by three gas discharge tube (U1, U2, U3) and first resistance (R1), second resistance (R2), first inductance (L1), second inductance (L2) constitutes, a cross-over connection in these three gas discharge tubes is between this transmitter incoming line and output line, in addition two gas discharge tubes be connected across respectively the incoming line of this transmitter and output line over the ground between, these three gas discharge tubes have the bleed off electric energy power of 10KA and less than reaction time of 1us, first resistance (R1) and first inductance (L1), second resistance (R2) and second inductance (L2) are serially connected in the incoming line of this transmitter respectively, constitute first order time delay circuit on the output line to next stage bleed off electricity;
Second level circuit is by three solid discharging tube (U4, U5, U6) and the 3rd inductance (L3) and the 4th inductance (L4) constitute, one in these three solid discharging tubes is connected across this transmitter incoming line through first resistance (R1), first contact behind first inductance (L1) and this transmitter output line are through second resistance (R2), between second contact of second inductance (L2), two other solid discharging tube is connected across first contact respectively, between second contact and the ground, these three solid discharging tubes have≤reaction time of 10nS, and the 3rd inductance (L3) and the 4th inductance (L4) constitute respectively to the second level of next stage vent discharge time delay circuit;
Tertiary circuit is by three Transient Suppression Diode (TVS1, TVS2, TVS3) and first resettable fuse (F1) and second resettable fuse (F2) constitute, one in these three Transient Suppression Diodes is connected across this transmitter incoming line through first resistance (R1), first inductance (L1), the 3rd contact behind the 3rd inductance (L3) and this transmitter output line are through second resistance (R2), second inductance (L2), between the 4th contact behind the 4th inductance (L4), two other transient state diode is connected across the 3rd contact respectively, between the 4th contact and the ground, these three Transient Suppression Diodes have≤reaction time of 1ns, and the clamping voltage of these three Transient Suppression Diodes is lower than the maximal work voltage of this transmitter.
2. lightning protection circuit as claimed in claim 1 is characterized in that, this lightning protection circuit satisfies the reaction time: gas discharge tube＞solid discharging tube＞Transient Suppression Diode; Shock resistance energy: gas discharge tube＞solid discharging tube＞Transient Suppression Diode; Clamping voltage: gas discharge tube＞solid discharging tube＞Transient Suppression Diode.
3. throw-in type piezoresistance liquid level transmitter that comprises that claim 1 or 2 described lightning protection circuits are formed, by the quick assembly of liquid level pressure resistance (2), transmitter (6), transmitter housing (7) and air guide balanced cable (20) are formed, the quick assembly of this pressure resistance is isolated by stainless steel ripple film that the silicon pressure resistance photosensitive elements be soaked in the silicone oil forms, and give this silicon pressure resistance photosensitive elements as the compression face pressure transmission with this stainless steel ripple film, the signal of drawing of this silicon pressure resistance photosensitive elements is exported by output cable after this transmitter amplifies, realize waterproof sealing based on side arm O type circle (3) between the back pressure side of the quick assembly of this pressure resistance and this transmitter housing, realize waterproof sealing between this air guide balanced cable and this transmitter housing, realize this silicon pressure resistance photosensitive elements and the atmospheric communication balance of external environment by the wireway in this air guide balanced cable, it is characterized in that: this lightning protection circuit is connected between the input-output line of this transmitter, the packed lightning protection circuit plate (11) that is fixed in the Stainless Steel Shell (10) that external diameter is φ 24mm～φ 40mm of this lightning protection circuit, realize waterproof sealing between this Stainless Steel Shell and this transmitter housing, this lightning protection circuit connects this transmitter shell and is grounded.
4. throw-in type fluid level transmitter as claimed in claim 3, it is characterized in that, the affixed anti-drift of compression face one end (1) of the quick assembly of this pressure resistance, and realize that by the water inlet on this anti-drift the compression face of the quick assembly of this pressure resistance is communicated with extraneous liquid phase, thereby realize the impression of fluid pressure to external world.
5. throw-in type fluid level transmitter as claimed in claim 4 is characterized in that, this water inlet adopts the double-T shaped hole with minimizing fluid dynamics effects to disappear dynamic pressure diversion header structure to adapt to quick circulating water application operating mode.
6. throw-in type fluid level transmitter as claimed in claim 4 is characterized in that, this water inlet adopts the ring-like hole with minimizing fluid dynamics effects to disappear dynamic pressure diversion header structure to adapt to circulating water application operating mode at a slow speed.
7. throw-in type fluid level transmitter as claimed in claim 3, it is characterized in that, this air guide balanced cable, by cable sheath (21), the shielding conductor of internal core wire and wrapped this internal core wire (14) is formed, this cable sheath is by the polyethylene of anti-water insulation, polyvinyl chloride or Polyurethane plastics are made, this internal core wire is that the wireway (13) of material is formed by cable tail (12) with polypropylene or polytetrafluoroethylene, extruding realizes waterproof sealing based on the thick O type of silicon rubber circle (16) between this air guide balanced cable and this transmitter housing, this cable lead division is coated with nitrile rubber wire bushing (19) simultaneously, and emits (18) to be rotated with in this transmitter housing afterbody with line ball and realize fixing.
8. throw-in type fluid level transmitter as claimed in claim 3, it is characterized in that this transmitter is the two-wire system liquid level transmission circuit of 4-20mA output signal, adopt the XTR101 circuit of anti-overcurrent and mistake pressure, have 40V maximal work voltage, the clamping voltage of this Transient Suppression Diode is 36V.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2005100379803A CN100373731C (en) | 2005-03-04 | 2005-03-04 | Lightningproof circuit and immersion type piezoresistance liquid level transmitter with the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2005100379803A CN100373731C (en) | 2005-03-04 | 2005-03-04 | Lightningproof circuit and immersion type piezoresistance liquid level transmitter with the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1829033A CN1829033A (en) | 2006-09-06 |
| CN100373731C true CN100373731C (en) | 2008-03-05 |
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| Application Number | Title | Priority Date | Filing Date |
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| CNB2005100379803A Expired - Fee Related CN100373731C (en) | 2005-03-04 | 2005-03-04 | Lightningproof circuit and immersion type piezoresistance liquid level transmitter with the same |
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Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101546901B (en) * | 2009-05-07 | 2012-09-26 | 北京玛斯特系统工程有限公司 | Circuit protection device for building automation system |
| CN101882784A (en) * | 2010-06-30 | 2010-11-10 | 广西地凯科技有限公司 | Lightning protection method for solar cell panel |
| CN103414177A (en) * | 2013-07-26 | 2013-11-27 | 北京广利核系统工程有限公司 | Electromagnetic protection circuit of analog signal input line |
| CN105004470A (en) * | 2015-07-10 | 2015-10-28 | 四川奇胜科技有限公司 | Pressure transmitter capable of stabilizing power supply voltage |
| CN105043645A (en) * | 2015-07-10 | 2015-11-11 | 四川奇胜科技有限公司 | Pressure transmitter convenient to debug |
| SE539127C2 (en) * | 2015-08-20 | 2017-04-11 | Anders Karlzon Med Firma Zitt Innovation | A surge arrester for a domestic robot assembly |
| CN106505842B (en) * | 2016-10-19 | 2019-09-10 | 飞亚达（集团）股份有限公司 | Airborne DC power supply |
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|---|---|---|---|---|
| CN2315696Y (en) * | 1997-11-25 | 1999-04-21 | 石峰 | Discharge type protector |
| CN2321155Y (en) * | 1997-12-08 | 1999-05-26 | 栖霞市供电公司 | Lightening arrester for electronic equipment |
| JP2004080970A (en) * | 2002-08-22 | 2004-03-11 | Hitachi Kokusai Electric Inc | Protective circuit for lightning surge |
| JP2004254487A (en) * | 2003-02-24 | 2004-09-09 | Nippon Kouatsu Electric Co | Lightning surge protection method |
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2005
- 2005-03-04 CN CNB2005100379803A patent/CN100373731C/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2315696Y (en) * | 1997-11-25 | 1999-04-21 | 石峰 | Discharge type protector |
| CN2321155Y (en) * | 1997-12-08 | 1999-05-26 | 栖霞市供电公司 | Lightening arrester for electronic equipment |
| JP2004080970A (en) * | 2002-08-22 | 2004-03-11 | Hitachi Kokusai Electric Inc | Protective circuit for lightning surge |
| JP2004254487A (en) * | 2003-02-24 | 2004-09-09 | Nippon Kouatsu Electric Co | Lightning surge protection method |
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