CN1426620A - Digital instrumentation - Google Patents
Digital instrumentation Download PDFInfo
- Publication number
- CN1426620A CN1426620A CN 01808737 CN01808737A CN1426620A CN 1426620 A CN1426620 A CN 1426620A CN 01808737 CN01808737 CN 01808737 CN 01808737 A CN01808737 A CN 01808737A CN 1426620 A CN1426620 A CN 1426620A
- Authority
- CN
- China
- Prior art keywords
- power
- instrument
- voltage
- power limitation
- area
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H9/00—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection
- H02H9/008—Intrinsically safe circuits
Landscapes
- Emergency Protection Circuit Devices (AREA)
- Arrangements For Transmission Of Measured Signals (AREA)
- Safety Devices In Control Systems (AREA)
Abstract
A digital instrumentation system has a power supply means (36) which supplies power to at least one instrument (3) located in a hazardous area (5). Also located in the hazardous area (5) is power limiting means (27) for limiting the power supplied to each instrument (3).
Description
The present invention relates to digital instrument, and be particularly related to the power of digital instrument transmit and with the communication of digital instrument.
Many houses, structures and facility etc. have such zone and area, promptly need the process that monitors and control in this zone.These zones are considered to dangerous as the consequence that may pollute of band blast or inflammable gas or liquid.Latent dangerous factor such as spark, electric arc and temperature need be maintained at lsafety level in the deathtrap.Can use the instrument that is positioned at the deathtrap to detect and control, information be propagated to Other Instruments and/or controller by cable.Such as on the platform of Petroleum Production, the interior temperature in zone that may comprise blast or inflammable gas can be by the local apparatus measures that is connected with remote controllers, and these remote controllers can give the alarm when arriving dangerous high scale.
Some are arranged about use the regulation of the electric equipment such as instrument in the deathtrap.Such as, in the zone that may comprise inflammable gas, equipment must or be packed and protect with suitable blast or burning protective cover, and perhaps equipment must be made into inherently safe.For inherent safety, to or must be limited in can not producing in any case dangerous level by the power supply that is positioned at the deathtrap and provides.In other words, the energy level in the equipment must be such, promptly under the situation of short circuit, can not light any inflammable gas that is present in the zone.Inherent safety has such advantage, comprises that promptly the electric equipment of instrument can or interrupt except that de-energisation can shifting out in the deathtrap such as the power supply of electrical separation device.
The power limitations that in any zone inherent safety is required is to be determined by the character that easily occupies this regional hazardous material.Such as, gas is classified according to their light off characteristics.Need the gas classification of minimum energy ignition need the restriction maximum of power supply of confession.For inherent safety given to the detailed description of gas classification by the annex A of standard EN 50014.
A kind of like this trend that tends to instrument system is arranged recently, and promptly some instruments are shared same transmission line, feedback or main line, or are hung on same transmission line, feedback or the main line.Also use this line between controller and instrument, to transmit communication signal to and fro.Usually, instrument is the DC power supply, and communication signal is digitally coded AC waveform.Normally, the AC communication signal is superimposed on the DC supply voltage.There is multiple different type in such system, comprises that those are in the well-known system under appointment HART, basic Fieldbus and Profibus of Britain.
In Fig. 1, described the arrangement of typical inherently safe Fieldbus (fieldbus) system.This is arranged with transmission line 6, and power is sent to two or more instruments 3 in the deathtrap 5 by this line based on inherently safe.Mainly the reliable voltage clamper of forming by voltage stabilizing didoe 52 and reliably current-limiting resistor device 51 by line 6 with the Power Limitation of transmission in inherently safe level.Each instrument 3 is connected with transmission line 6 by branch line or joint 4.
Bus and similarly based on the problem that occurs in the inherently safe operated system be at the scene is to the quantitative restriction of the instrument that can share same transmission line.Ampere between the common needs 0.01 to 0.03 of fieldbus instrument and the volt between 9 to 32 work.Instrument also needs and can guarantee 1.2 watts maximum power.Before the total amount arrival maximum that instrument power needs can provide power,, not that a lot of equipment can both be shared this line for inherently safe transmission line.Give an example, the instrument that needs 1.2 watts of 0.02 ampere fieldbus instrument and mesh powers 9 volts of minimum values, for inherent safety, needing maximum is to operate in the zone of 22 volts and 0.224 ampere, for short fieldbus length of transmission line, the actual maximum number of instrument is approximately four.Be that known length is that the transmission line of 1Km will have sizable resistance in place, and the loss of voltage can be directly proportional with the electric current that transmits by line such as oil plant.As a result, the actual maximum number of instrument can be dropped to three or still less.In addition, in the inherently safe compliance of decision, do not consider the resistance of transmission line.The DC supply voltage needs referred maximum to allow voltage drop along the line, and this forces current-limiting resistor higher relatively value to be arranged to reach and the mesh power that hangs instrument on line.Thereby, high-resistance needs have been limited electric current again.
EP0666631 has disclosed a kind of digital instrument system, and wherein the configuration of the device of pressure limiting or current limliting spatially separates with power supply, and the connection right and wrong between power supply and the restraint device are inherently safe.
The purpose of this invention is to provide a kind of improved digital instrument system.
The invention provides a kind of digital instrument system, it comprise supply unit, at least one be positioned at the hazardous area instrument, be used for power from supply by the hazardous area be sent to each instrument transmission line device, be used for limiting the power limited device of supply power and being positioned at the power limitation device that the hazardous area is used to limit the power that transmits at least one instrument from transmission line by transmission line device.
By power limitation device being set, that is to say that away from electric supply installation power limitation device is set, the power in the line apparatus can remain height, thereby make the line length and/or the quantity of the instrument of common lines device be maximum in the transmission line device downstream.Power limitation device can be with the Power Limitation of carrying at least one instrument inherently safe level in the hazardous area.Equally, power limitation device can be with the Power Limitation of carrying at least one instrument under inherently safe level.In the situation to the ohmic load short circuit of instrument, the power of inherently safe level still enough is elevated to danger level with the temperature of instrument, and further power-limiting can prevent this possibility.
Preferably, power limitation device comprises current-limiting apparatus, and it can preferably comprise resistance device.Current-limiting apparatus can be additionally or is replacedly comprised fuse equipment and/or switching device.At least each instrument can have special current-limiting apparatus.
Power limitation device can additionally or alternatively comprise pressure limiting device, is used to clamp down on the voltage to instrument or the conveying of each instrument.Pressure limiting device can comprise the voltage stabilizing didoe based on voltage clamp or any other similar or equivalent voltage clamp form.
Basic voltage for hazardous area that is provided with instrument or area assessment is the voltage that enters the inherently safe point in zone or area.The power limitation device that comprises pressure limiting device makes the voltage of the inherently safe point of carrying by power limitation device that enters zone or area be lower than the voltage of being exported by electric supply installation.Have lower voltage at that point and make used low current limit resistance device, and electric current can excessively not limited power demand and instrument coupling.
Power limitation device can be carried power to a plurality of instruments, each instrument can be positioned at hazardous area and the area of other area with identical or different inherently safe demand, zone.Instrument can be starlike or multiterminal configuration.Power from power limitation device can not only be transported to each instrument, also can be transported to the power limitation device that is arranged in same or another hazardous area, thereby and gives Other Instruments with power delivery.
Preferably, will arrive inherently safe level by the Power Limitation that transmission line provides in the area in power level device for limiting zone between electric supply installation and power limitation device.At least one instrument can with electric supply installation and power limitation device between inherently safe require different, in the usually more strict area.In other words, Power Limitation is preferably finished by bi-level treatment, makes full use of the maximum allowable power in each area and keeps inherent safety in each area simultaneously.
Power limited device preferably comprises pincers stream device, and it preferably comprises resistance device.Pincers stream device replacedly or additionally comprises fuse equipment and/or switching device.Fuse and/or switching device can be warm starts.The power level device for limiting can be alternatively or is additionally comprised clipper, and it can comprise the voltage stabilizing didoe based on voltage clamp or any other similar or equivalent voltage clamp form.Fuse and/or switching device can be in response to the temperature of clipper by warm starts.
In addition preferably, when power limitation device and power limited device all comprise resistance device, thereby the value of resistance device can be mated the power that makes between electric supply installation and at least one instrument respectively and is transmitted as maximum.
In addition preferably, system comprises the regulator that is used to regulate the input voltage from the transmission line to the power limitation device.Regulator can be the structure of serial or parallel connection.In parallel-connection structure, regulator can have for numeral or AC signal and/or high impedance for the high frequency voltage component and the low resistance for dc voltage.In other words, regulator can play the effect of low pass voltage parallel regulator, only with dc voltage and AC voltage limit in predetermined threshold value, allow near threshold value AC exchange communication signal by and unaffected.The regulator that comprises the inductance of parallel-connection structure and voltage stabilizing didoe plays the effect of low pass voltage parallel regulator.In cascaded structure, regulator can comprise field-effect transistor.
Regulator is used for the DC level of electric supply installation is limited under the inherently safe pincers voltage levels of being forced by the power limitation device that comprises pressure limiting device, thereby prevents that pressure limiting device is adversely affected, the AC communication signal of clamping down on or prune.
System also can comprise the additional current-limiting apparatus between electric supply installation and power limitation device.Additional current-limiting apparatus can comprise resistance device and/or fuse equipment.
System also can comprise transducer.
Electric supply installation can be positioned at the safety zone.Electric supply installation can comprise digital I/O section, by coupler, links to each other with transmission line such as transformer.Coupler can have the circuit of two or three electrical insulation and can support one or multiple-transmission-line more.Numeral I/O section can be by inherently safe insulation blocking, in this case, can not need the electrical insulation with the coupler of transmission line.Power can by from the coupler of one or more power supplys to one or more multiple-transmission-line supply with, this power supply can be a utility power.Power supply can be subjected to the protection of inherently safe insulation, can not need the electrical insulation of power supply in this case.In addition, coupler can have its oneself power supply, onboard or not onboard, thereby does not directly power to coupler.Can be connected with single section and surpass one coupler, thereby the connection of section can form being connected of daisy chain, bridge shape or multiterminal of coupler and bus by bus.
The present invention describes in conjunction with example referring now to figure below, wherein:
Fig. 1 is the schematic diagram of the inherently safe fieldbus numeral instrument system of prior art;
Fig. 2 is the schematic diagram of digital instrument system;
Fig. 3 is the schematic diagram of another kind of digital instrument system;
Fig. 4 is the pressure regulation of using in Fig. 2 and system shown in Figure 3 and the schematic diagram of power limitation device;
Fig. 5 is the chart to the voltage influence of power limitation device shown in Figure 4;
Fig. 6 is the chart to the voltage influence of regulator shown in Figure 4;
Fig. 7 is the schematic diagram of a kind of structure of regulator output shown in Figure 4;
Fig. 8 is the schematic diagram of a kind of replaceable structure of power limitation device output shown in Figure 4;
Fig. 9 is the schematic diagram according to digital instrument system of the present invention;
Figure 10 is the schematic diagram according to another kind of digital instrument system of the present invention;
Figure 11-the 14th, the schematic diagram of other digital instrument system;
Figure 15 is the structural representation that is connected according to instrument of the present invention and digital instrument system output;
Figure 16 is the schematic diagram that also has a kind of digital instrument system according to of the present invention;
Figure 17 is the schematic diagram that is used to connect the transducer of digital instrument system according to the present invention;
Figure 18 is the schematic diagram that is used for the electric supply installation of digital instrument system according to the present invention; And
Figure 19 is the schematic diagram that is used for the electric supply installation of digital instrument system according to the present invention.
With reference to figure 2, press the DC power of electric supply installation 36 to transmit by transmission line 6 from the pincers of the extrinsic safety that is arranged in safe non-hazardous area (being meant the unrestricted hazardous area on line 5 left sides), pass hazardous area 5 and arrive three instruments 3 that are arranged in hazardous area 5.Is in the extrinsic lsafety level from supply 36 output for hazardous area 5, is necessary for transmission line 6 due care such as explosion proof enclosure is provided.Power is carried to each instrument 3 with relevant output 37 by branch line respectively from transmission line 6.Be superimposed upon on the supply voltage DC level is the AC communication signal of the information of carrying back and forth between controller (not shown) and instrument 3.In every branch line, there is the power limitation device with current-limiting resistance 27 forms also to be positioned among the hazardous area 5.Being connected between all three resistance 27 and line 6 and the branch line, because the extrinsic lsafety level of power, and be housed in the shell of due care.Output 37, as the result of the current limliting of being forced by their related resistors 27, each all is inherently safe for hazardous area 5.Therefore, before not being limited in the downstream of leaving electric supply installation 36 of inherently safe level in line 6 to the power of instrument, power level on the transmission line 6 can remain height thus, thereby can make the length of transmission line 6 and the instrument number of shared transmission line 6 be maximum.Transmission line 6 continues to remain height outside a line position of the branch line (not shown) that other links to each other with instrument.
With reference to figure 3, press the power of electric supply installation 38 to be conveyed through three instruments 3 that hazardous area 5 arrival are positioned at hazardous area 5 from the non-pincers of extrinsic safety by transmission line 6.Because the output that comes self-power supply device 38 provides suitable protection to the inherently safe level of hazardous area 5 right and wrong so be necessary for transmission line 6.Power is carried to each instrument 3 from transmission line 6 with relevant output 37 by branch line.Be superimposed upon on the supply voltage DC level is the AC communication signal of the information of carrying back and forth between controller (not shown) and instrument 3.Power is carried by the power limitation device 17 that also is arranged in hazardous area 5.Power limitation device 17 comprises current-limiting resistance 27 and clamps down on the pressure limiting circuit of the voltage of carrying in each output 37.In addition, the power that provides to power limitation device 17 is supplied with by the regulator 10 that is arranged in hazardous area 5 equally.Power limitation device 17 and regulator 10, because the extrinsic lsafety level of power, and all be housed in the shell 99 of identical due care.Power limitation device 17 with each output power export-restriction on 37 in the hazardous area 5 inherently safe level.Regulator 10 has guaranteed, the DC level of the supply voltage that provides to power limitation device 17 is limited or leaves behind to certain level, can not affect adversely, can not clamp down at power limitation device 17 under this level or prune to be superimposed upon AC communication signal on the dc voltage level.Transmission line 6 continues to remain height outside a line position of the branch line (not shown) that links to each other with instrument at other.
Owing to the decision of the compliance of hazardous area 5 desired inherently safe levels is based on the voltage of clamping down on of power limitation device 17, this voltage can be significantly less than the voltage by electric supply installation 38 outputs, resistance 27 in the power limitation device 17 can be lower than the resistance of the power demand that needs coupling instrument 3, so electric current can exceedingly not limited.
Shown in Figure 4 is the example of a suitable equivalent electric circuit, and this circuit is used for finishing at above Power Limitation and the voltage regulation function that uses that be provided with reference to figure 3 descriptions.Power limitation device 17 comprises voltage stabilizing didoe pincers depressor 23 and at least one current-limiting resistance 27.Pincers depressor 23 will limit the AC and the dc voltage of any direction that may be by passing power limitation device 17.The such a dc voltage that not only is used for to any instrument 3 power supplies, the device of the AC communication voltage that can also be used for superposeing on dc voltage is with restricted.Fig. 5 has described to have the performance of the power limitation device 17 of absolute voltage threshold value with illustrating, when to the dc voltage level that provides of pincers depressor 23 from operate as normal level 12 be increased to approaching, arrive absolute extremes 19 or at absolute extremes more than 19, the AC communication signal 20 that is superimposed upon on the dc voltage 16 can be affected, more precisely clipped wave.In order to prevent this problem, use the regulator that comprises inductance 25 and voltage stabilizing didoe 24 shown in Figure 4, with the voltage that limits or leave behind and provide to power limitation device 17.It is how to limit supply voltage that Fig. 6 has described regulator with illustrating, irrelevant with the input voltage shown on 9, thereby provides sufficient head room to surpass absolute extremes 19 sometimes to prevent the AC communication signal.Simultaneously, 20 maintenances of AC communication signal are not subjected to the influence of regulator 10.
Fig. 3 and any one or more resistance before regulator 10 shown in Figure 4 can be integrated resistor and/or transmission line resistance, and/or they also can finish current limliting and/or Power Limitation function in electric supply installation.
Fig. 7 has showed above-mentioned power limitation device with reference to figure 4-6, has the output 37 that is referred to as star topology.The inherently safe level of each output 37 depends on the maximum voltage that pincers depressor 23 is allowed and the value of related resistors 27.Therefore select the power of the value of resistance 27 with the restriction appropriate area, output will enter this zone and mesh power requirement respectively.Each resistance 27 can be made up of one or more resistance, can be by one or more fuses replacement or additional.
Fig. 8 has described the replaceable structure of power limitation device shown in Figure 7, has the output 37 that is referred to as multiterminal configuration.Output 37 directly is delivered to instrument 3 or other power limitation device with power.Resistance 27 can intactly be housed in the suitable shell 35 with being connected of transmission line 6 separately or covers on individually in the suitable shell 34 along them.At shell 35 on one side, transmission line 6 continues to be connected with other branch's (not shown).Equally, each resistance 27 can be made up of one or more resistance, can or replenish by one or more fuses replacements.
One embodiment of the present of invention in Fig. 9, have been described.Come the power of self-power supply device 40 to be limited to the inherently safe level in area 5 ' by power limited device with hazardous area 5.Power limited device comprises voltage stabilizing didoe voltage clamp 41 and pincers leakage resistance 42.Inherently safe power is sent to the area 5 that is positioned at hazardous area 5 by area 5 ' " three instruments 3, wherein hazardous area 5 has the inherently safe requirement stricter more than area 5 '.Power is carried to each instrument 3 respectively from transmission line 6 with relevant output 37 by branch line.Be superimposed upon on the supply voltage DC level is the AC communication signal of the information of carrying back and forth between controller (not shown) and instrument 3.In every branch line, what be positioned at hazardous area 5 ' in addition equally is the power limitation device of form with current-limiting resistance 27.Connection and branch line between all three resistance 27 and the line 6 are covered with the inherently safe requirement of satisfying area 5 ', and this area is between electric supply installation 40 and shell 77.Required power restraint device 27 is to satisfy area 5 " stricter inherently safe requirement, wherein instrument 3 is arranged in this area.Thereby resistance 27 makes output 37 for zone 5 by the power that transmits on the further restraining line 6 " inherently safe.In other words, power drops to area 5 " requirement.According to area 5 ' and 5 " in the bi-level treatment of safety requirements, power transmits and makes full use of each area 5 ' and 5 by this area " maximum allowable power.In addition, thus mesh power limits the value of resistance 42 and Power Limitation resistance 27 guarantees that from electric supply installation 40 to instrument 3 maximum power transmits.
Figure 10 has described another embodiment of the present invention, done variation to above with reference to figure 9 described embodiment, wherein, be sent to inherently safe shell 77 from the power of inherently safe electric supply installation 40 area 5 ' by an inherently safe level, in this shell, clamp down on all modes of voltage and current to be mentioned with reference to figure 5-7 by regulator 10 regulation voltages and by power limitation device 17, thereby make the area 5 by stricter safety requirements in output 37 " conveying have inherently safely, wherein instrument 3 is positioned at this area.
Figure 11-14 has described the above-mentioned further variation that is provided with (label that same section is given is identical), and wherein each output 37 is not to be connected with instrument 3, but is connected with the above same another class power limitation device of describing.
Figure 15 shows in above-mentioned any setting one, two or more equipment 3 and each output 37 possibility that are connected.
Figure 16 has described the further variation on above-mentioned the setting, wherein the output from the transmission line 6 of power limitation device 17 is that basic delivering power arrives another current-limiting apparatus by another hazardous area 96 with extrinsic safety, and this current-limiting apparatus is used for limiting to the power that has with the Other Instruments (not shown) conveying in 96 other hazardous areas 100 of different inherently safe levels, zone.
Figure 17 has schematically described the transducer 200 that can use in system according to the present invention, such as, need in conversion under the situation of power supply on online 6, that is to say, from the extrinsic lsafety level in first area to inherently safe level, and then use according to power limitation device of the present invention, with the inherently safe level of Power Limitation in second area, this level is the inherently safe level stricter than first area.Each input of transducer 200 can have the output above one.
During each is provided with, will understand is that the electric supply installation that is positioned at the place of safety comprises the digital communication signal input/output device, can adopt the example of form shown in Figure 180 above-mentioned.Single digital I/O section (not shown) is connected with multiple transmission line 6 by coupler 102 with bus 100, every transmission line 6 all has the above power limitation device of describing with reference to any embodiment of the present invention, comprises the circuit that the coupler 102 of reliable transformer has two inherently safe electrical insulation.Power is shared or public electric supply installation 104 is sent to transmission line 6 from one or more by coupler 102, wherein electric supply installation each equally all comprise the transformer that is positioned at the place of safety reliably, each place of safety all has inherently safe electrical insulation.
What Figure 19 described is the inherently safe electric supply installation 40 that is used for transmission power on the transmission line 6, and it has reached the inherently safe level in zone 5.Institute's power supply source is limited by the power lsafety level device for limiting that comprises voltage clamp 401 and current-limiting resistance 402.The thermal switch that ' upstream ' or ' downstream ' located in the line 6 or the line of return or fuse 403 and voltage clamp 401 thermal couplings.Under the situation that voltage 401 becomes very hot, thereby switch or fuse 403 are activated the electric current that is cut to voltage clamp 401.Voltage clamp 401 can comprise the voltage stabilizing didoe of high watt capacity, and it is connected with the fin of corresponding high power capacity, thereby take up room very much usually.Having had hot protection has just given up thereby the needs of this fin have also been reduced space requirement.Switch or fuse 403 also can with resistance 402 thermal couplings, and can provide additional fuse 404 in the upstream or the downstream of switch or fuse 403.
Claims (26)
1. a digital instrument system comprises: electric supply installation; At least one is positioned at the instrument in hazardous area; Transmission line device is used for that power is passed the hazardous area from power supply and is sent at least one instrument; Power limited device is used to limit the power that provides by transmission line device; And the power limitation device that is arranged in the hazardous area, be used to limit the power of carrying at least one instrument from transmission line.
2. according to the system of claim 1, it is characterized in that power limitation device comprises current-limiting apparatus.
3. according to the system of claim 2, it is characterized in that current-limiting apparatus comprises resistance device.
4. according to the system of claim 3, it is characterized in that current-limiting apparatus additionally or alternatively comprises fuse equipment and/or switching device.
5. according to the system of claim 1, it is characterized in that at least one instrument has special-purpose current-limiting apparatus.
6. according to the system of claim 2, it is characterized in that power limitation device additionally or alternatively comprises pressure limiting device.
7. according to the system of claim 6, it is characterized in that pressure limiting device comprises the voltage stabilizing didoe based on voltage clamp or any other voltage clamp.
8. according to the system of arbitrary claim in the claim 1 to 7, it is characterized in that, power limitation device is carried power to a plurality of instruments, each instrument is arranged in the area that has the hazardous area of identical or different inherently safe requirement with zone any one and other area.
9. system according to Claim 8 is characterized in that, described a plurality of instruments are with star topology or multiterminal configuration configuration.
10. according to the system of any aforementioned claim, it is characterized in that, carry to the power limitation device that other is arranged in same or another hazardous area from the power of power limitation device, thereby to another instrument transmission power at least.
11. the system according to any aforementioned claim is characterized in that, the power level device for limiting will be limited to inherently safe level along the power of transmission line supply in the area in the zone between electric supply installation and power limitation device.
12. the system according to claim 11 is characterized in that, instrument or at least one instrument with electric supply installation and power limitation device between the inherently safe of area require in the different areas.
13. the system according to any aforementioned claim is characterized in that, power limited device comprises pincers stream device.
14. the system according to claim 13 is characterized in that, pincers stream device comprises resistance device.
15. the system according to claim 14 is characterized in that, pincers stream device is replaceable or additionally comprise fuse equipment and/or switching device.
16. the system according to claim 15 is characterized in that, fuse and/or switching device are warm starts.
17. the system according to claim 14 is characterized in that, power limited device is replaceable or additionally comprise clipper.
18. the system according to claim 17 is characterized in that, clipper comprises the voltage stabilizing didoe based on voltage clamp or any other voltage clamp.
19. system according to claim 1, it is characterized in that, power limitation device comprises resistance device, power limited device comprises resistance device, and the value of Power Limitation resistance device and power limited resistance device is mated, thereby the power between electric supply installation and instrument or at least one instrument is transmitted maximization.
20. the system according to any aforementioned claim is characterized in that, comprises regulator, is used to regulate the voltage output from the transmission line to the power limitation device.
21. the system according to claim 20 is characterized in that, regulator can be the structure of serial or parallel connection.
22. the system according to claim 21 is characterized in that, is that the regulator of structure has for numeral or AC signal and/or for the high impedance of high frequency voltage component and for the low resistance of dc voltage with the parallel connection.
23. the system according to claim 22 is characterized in that, regulator comprises inductance and voltage stabilizing didoe.
24. the system according to any claim of claim 20 to 22 is characterized in that regulator is a cascaded structure, comprises field-effect transistor.
25. the system according to any aforementioned claim is characterized in that, is included in the additional current-limiting apparatus between electric supply installation and the power limitation device.
26. the system according to claim 25 is characterized in that, additional current-limiting apparatus comprises resistance device and/or fuse equipment and/or switching device.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB0010010A GB0010010D0 (en) | 2000-04-25 | 2000-04-25 | Digital instrumentation |
| GB0010010.7 | 2000-04-26 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN1426620A true CN1426620A (en) | 2003-06-25 |
Family
ID=9890444
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 01808737 Pending CN1426620A (en) | 2000-04-25 | 2001-04-26 | Digital instrumentation |
Country Status (8)
| Country | Link |
|---|---|
| EP (1) | EP1277265A1 (en) |
| JP (1) | JP2003532209A (en) |
| CN (1) | CN1426620A (en) |
| AU (1) | AU5236001A (en) |
| BR (1) | BR0110285A (en) |
| CA (1) | CA2406752A1 (en) |
| GB (1) | GB0010010D0 (en) |
| WO (1) | WO2001082442A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110967435A (en) * | 2018-09-28 | 2020-04-07 | 西门子股份公司 | Fluid analyzer |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102013103627A1 (en) * | 2013-04-11 | 2014-10-16 | Endress + Hauser Flowtec Ag | Field device with a protection circuit |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4403961C2 (en) * | 1994-02-04 | 1997-07-03 | Hartmann & Braun Ag | Feeding system for an intrinsically safe fieldbus |
| DE4407117A1 (en) * | 1994-03-04 | 1995-09-07 | Licentia Gmbh | Supply of DC consumers from rectifier though long lines |
| WO1999045621A1 (en) * | 1998-03-06 | 1999-09-10 | Abb Patent Gmbh | Field bus system with a field bus distributor |
-
2000
- 2000-04-25 GB GB0010010A patent/GB0010010D0/en not_active Ceased
-
2001
- 2001-04-26 CA CA002406752A patent/CA2406752A1/en not_active Abandoned
- 2001-04-26 WO PCT/GB2001/001847 patent/WO2001082442A1/en active Application Filing
- 2001-04-26 CN CN 01808737 patent/CN1426620A/en active Pending
- 2001-04-26 JP JP2001579418A patent/JP2003532209A/en active Pending
- 2001-04-26 BR BR0110285-0A patent/BR0110285A/en not_active IP Right Cessation
- 2001-04-26 EP EP01925675A patent/EP1277265A1/en not_active Withdrawn
- 2001-04-26 AU AU52360/01A patent/AU5236001A/en not_active Abandoned
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110967435A (en) * | 2018-09-28 | 2020-04-07 | 西门子股份公司 | Fluid analyzer |
| US11378555B2 (en) | 2018-09-28 | 2022-07-05 | Siemens Aktiengesellschaft | Fluid analyzer |
Also Published As
| Publication number | Publication date |
|---|---|
| BR0110285A (en) | 2003-03-05 |
| AU5236001A (en) | 2001-11-07 |
| EP1277265A1 (en) | 2003-01-22 |
| JP2003532209A (en) | 2003-10-28 |
| CA2406752A1 (en) | 2001-11-01 |
| WO2001082442A1 (en) | 2001-11-01 |
| GB0010010D0 (en) | 2000-06-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6154679A (en) | Bus isolator for industrial control system providing intrinsically safe operation | |
| CN101257428B (en) | Asi network for areas subject to explosive risk | |
| DE4403961C2 (en) | Feeding system for an intrinsically safe fieldbus | |
| US7312716B2 (en) | Wireless communication using an intrinsically safe design for use in a hazardous area | |
| DE3927309A1 (en) | MODULE INTERFACE WITH BUILT-IN SECURITY | |
| EP0027039A2 (en) | Power supply systems for hazardous locations | |
| JP2008210384A6 (en) | ASI network for explosion hazard areas | |
| EP0323525A1 (en) | Digital differential signal transmission apparatus having intrinsically safe barrier | |
| EP1060552B1 (en) | Field bus system with a field bus distributor | |
| CN1426620A (en) | Digital instrumentation | |
| CN101346867B (en) | Circuit arrangement featuring explosion protection | |
| EP0310281B1 (en) | Electrical safety barriers | |
| EP2704332B1 (en) | Emergency/safety lighting unit and method for controlling the same | |
| US20040080890A1 (en) | Digital instrumentation | |
| US20180359833A1 (en) | Active Power Distribution System For Low-Voltage Lighting And Other Applications | |
| US8174153B2 (en) | Communication interface between a control unit and a high voltage unit | |
| RU2231903C2 (en) | High-level voltage converter | |
| DE102021102357A1 (en) | system and field device | |
| JPH04121017A (en) | Dc superimposed signal transmission system of explosion-proof type | |
| US11005389B2 (en) | Power electronics system comprising parallel inverters | |
| JP2021083184A (en) | Ground fault protection method | |
| EP1357661B1 (en) | Circuit design for variable application of an input voltage to a circuit | |
| US2462094A (en) | Electrical safety interlocking system | |
| JPS62188525A (en) | Signal transmission equipment | |
| SE9304318L (en) | Device for limiting incoming surges to a protective object via an electric high voltage power line |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| ASS | Succession or assignment of patent right |
Owner name: HUMBELL CO., LTD. Free format text: FORMER OWNER: HAWKE CABLE GLANDS LTD. Effective date: 20050408 |
|
| C41 | Transfer of patent application or patent right or utility model | ||
| TA01 | Transfer of patent application right |
Effective date of registration: 20050408 Address after: London, England Applicant after: Henry M Bell Ltd Address before: Lancashire Applicant before: Hawke Cable Glands Ltd. |
|
| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |