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GB1412036A - Interface assembly in a process control system for use where there is a fire hazard - Google Patents

Interface assembly in a process control system for use where there is a fire hazard

Info

Publication number
GB1412036A
GB1412036A GB1101673A GB1101673A GB1412036A GB 1412036 A GB1412036 A GB 1412036A GB 1101673 A GB1101673 A GB 1101673A GB 1101673 A GB1101673 A GB 1101673A GB 1412036 A GB1412036 A GB 1412036A
Authority
GB
United Kingdom
Prior art keywords
interface
signal
process control
supply
control system
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.)
Expired
Application number
GB1101673A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Schneider Electric Systems USA Inc
Original Assignee
Foxboro Co
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Foxboro Co filed Critical Foxboro Co
Publication of GB1412036A publication Critical patent/GB1412036A/en
Expired legal-status Critical Current

Links

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

  • Safety Devices In Control Systems (AREA)
  • Emergency Protection Circuit Devices (AREA)
  • Arrangements For Transmission Of Measured Signals (AREA)

Abstract

1412036 Protective circuits in process control systems FOXBORO CO 7 March 1973 [6 April 1972] 11016/73 Heading H2H An interface assembly in a process control system is located between a control room and a process area and comprises an interface 10 which includes current limiting resistors 20, 21, 24 and a voltage limiter 30 for limiting the voltage supplied to the interface from a power supply 28. On the process side 12 of the system a signal transmitter 14 and a valve positioner 15 are located in a hazardous process area 16 where a risk of ignition due to a fault in electrical equipment may exist. A signal from the transmitter 14 is supplied via a differential amplifier 19 to control instruments 13 on the control room side 11 of the system. The instruments 13 supply a signal to the valve positioner 15 via an amplifier 25 and the voltage limiter 30 supplies power on output buses 32, 33 and 34, 35 to each side of the interface. If an excess voltage occurs on cable 31 a thyristor (45), Fig. 2 (not shown), is triggered by a Zener diode (46) to short circuit the supply.
GB1101673A 1972-04-06 1973-03-07 Interface assembly in a process control system for use where there is a fire hazard Expired GB1412036A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US24154572A 1972-04-06 1972-04-06

Publications (1)

Publication Number Publication Date
GB1412036A true GB1412036A (en) 1975-10-29

Family

ID=22911132

Family Applications (1)

Application Number Title Priority Date Filing Date
GB1101673A Expired GB1412036A (en) 1972-04-06 1973-03-07 Interface assembly in a process control system for use where there is a fire hazard

Country Status (7)

Country Link
JP (1) JPS4914881A (en)
CA (1) CA983569A (en)
DE (1) DE2316039C2 (en)
FR (1) FR2179151B1 (en)
GB (1) GB1412036A (en)
IT (1) IT982957B (en)
NL (1) NL7304743A (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4799125A (en) * 1986-09-05 1989-01-17 Raychem Limited Circuit protection arrangement
GB2222037A (en) * 1988-08-19 1990-02-21 Cooper Ind Inc Intrinsic safety module interface
GB2232021A (en) * 1989-03-02 1990-11-28 Hemscheidt Maschf Hermann An intrinsically safe power supply
GB2238191A (en) * 1989-10-19 1991-05-22 Drexelbrook Controls Intrinsically safe system
WO2016141974A1 (en) * 2015-03-10 2016-09-15 Hewlett-Packard Development Company, L.P. Safety protection circuit
EP3444912A1 (en) * 2017-08-16 2019-02-20 Honeywell International Inc. Intrinsic safety (is) barrier with separat circuits for voltage clamping and energy limiting

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2359532A1 (en) * 1976-07-20 1978-02-17 Cit Alcatel Balanced load protection circuit - is controlled from pilot network and parallel nominal load connected across supply
SE414357B (en) * 1978-08-17 1980-07-21 Asea Ab OVERVOLTAGE PROTECTION FOR PROTECTION OF SEMICONDUCTOR COMPONENTS OF LOW EFFECT TYPE
DE3832068A1 (en) * 1988-09-21 1990-03-22 Stahl R Schaltgeraete Gmbh EXPLOSION PROTECTED ELECTRICAL SAFETY BARRIERS

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1133750A (en) * 1966-12-02 1968-11-13 Foxboro Yoxall Ltd Electrical barrier device
US3631264A (en) * 1970-02-11 1971-12-28 Sybron Corp Intrinsically safe electrical barrier system and improvements therein

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4799125A (en) * 1986-09-05 1989-01-17 Raychem Limited Circuit protection arrangement
US4807081A (en) * 1986-09-05 1989-02-21 Raychem Limited Circuit protection arrangement
GB2222037A (en) * 1988-08-19 1990-02-21 Cooper Ind Inc Intrinsic safety module interface
US4954923A (en) * 1988-08-19 1990-09-04 Cooper Industries, Inc. Intrinsic safety module interface
GB2232021A (en) * 1989-03-02 1990-11-28 Hemscheidt Maschf Hermann An intrinsically safe power supply
GB2232021B (en) * 1989-03-02 1993-07-28 Hemscheidt Maschf Hermann An intrinsically safe power supply unit
GB2238191A (en) * 1989-10-19 1991-05-22 Drexelbrook Controls Intrinsically safe system
WO2016141974A1 (en) * 2015-03-10 2016-09-15 Hewlett-Packard Development Company, L.P. Safety protection circuit
US10418806B2 (en) 2015-03-10 2019-09-17 Hewlett-Packard Development Company, L.P. Safety protection circuit
EP3444912A1 (en) * 2017-08-16 2019-02-20 Honeywell International Inc. Intrinsic safety (is) barrier with separat circuits for voltage clamping and energy limiting

Also Published As

Publication number Publication date
NL7304743A (en) 1973-10-09
DE2316039A1 (en) 1973-10-18
FR2179151A1 (en) 1973-11-16
IT982957B (en) 1974-10-21
AU5251773A (en) 1974-08-22
FR2179151B1 (en) 1977-08-05
JPS4914881A (en) 1974-02-08
CA983569A (en) 1976-02-10
DE2316039C2 (en) 1984-01-26

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Legal Events

Date Code Title Description
PS Patent sealed
433D Application made for revocation (sect. 33/1949)
433C Case decided by the comptroller ** specification amended (sect. 33/1949)
SP Amendment (slips) printed