EP0054407A1 - Circuit de protection d'un courant de charge - Google Patents

Circuit de protection d'un courant de charge Download PDF

Info

Publication number
EP0054407A1
EP0054407A1 EP19810305812 EP81305812A EP0054407A1 EP 0054407 A1 EP0054407 A1 EP 0054407A1 EP 19810305812 EP19810305812 EP 19810305812 EP 81305812 A EP81305812 A EP 81305812A EP 0054407 A1 EP0054407 A1 EP 0054407A1
Authority
EP
European Patent Office
Prior art keywords
switch
circuit
transistor
diode
potential
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.)
Granted
Application number
EP19810305812
Other languages
German (de)
English (en)
Other versions
EP0054407B1 (fr
Inventor
Stuart Charles Clatworthy
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.)
RESTBURY Ltd
Original Assignee
RESTBURY Ltd
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 RESTBURY Ltd filed Critical RESTBURY Ltd
Publication of EP0054407A1 publication Critical patent/EP0054407A1/fr
Application granted granted Critical
Publication of EP0054407B1 publication Critical patent/EP0054407B1/fr
Expired legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G08—SIGNALLING
    • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B29/00—Checking or monitoring of signalling or alarm systems; Prevention or correction of operating errors, e.g. preventing unauthorised operation
    • G08B29/18—Prevention or correction of operating errors
    • G08B29/20—Calibration, including self-calibrating arrangements
    • G08B29/22—Provisions facilitating manual calibration, e.g. input or output provisions for testing; Holding of intermittent values to permit measurement
    • G—PHYSICS
    • G08—SIGNALLING
    • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B29/00—Checking or monitoring of signalling or alarm systems; Prevention or correction of operating errors, e.g. preventing unauthorised operation
    • G08B29/12—Checking intermittently signalling or alarm systems
    • G08B29/14—Checking intermittently signalling or alarm systems checking the detection circuits
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H47/00—Circuit arrangements not adapted to a particular application of the relay and designed to obtain desired operating characteristics or to provide energising current
    • H01H47/002—Monitoring or fail-safe circuits

Definitions

  • the present invention relates to devices to protect against failure of switches. Such devices may also be used for testing switches without disturbing the system controlled by the switch.
  • a device tc ensure continuation of current supply to a load in the event of failure of a switch, the device comprising a circuit connected in parallel with the switch and comprising means to cause voltage drop thereby to produce a reduced potential in the circuit, and a diode arranged to prevent current flow in the circuit when the potential at the load side of the switch is higher than the reduced potential, and to allow current flow when said potential is reduced tc a value lower than the reduced potential by virtue of the switch opening.
  • the device further comprises means to detect current flow in the circuit.
  • the base of a transistor is connected to a point in the circuit between the voltage reducing means and the diode, the two other connections of the transistor forming part of an alarm circuit which conducts only when said transistor is biased on by current flow in said circuit caused by opening of the switch.
  • the alarm circuit may include a light emitting diode to give visible warning of switch opening.
  • a method of testing a normally closed switch which comprises the steps of: connecting in parallel to said switch a circuit which comprises in series means to cause voltage drop thereby to produce a reduced potential in the circuit, a diode to prevent current flow in the circuit when the potential at the load side of the switch is higher than the reduced potential, and a connection point to the base of a transistor located between said means to cause a voltage drop and said diode, the two other connections of the transistor forming part of an alarm circuit; opening the switch; and checking the alarm circuit output.
  • a method of testing a normally open switch which comprises the steps of: connecting in parallel with a second normally open switch and the load, a circuit which comprises in series means to cause voltage drop thereby to produce a reduced potential in the circuit, a connection point to the base of a transistor,and a dummy load; connecting the other connections of the transistor into ar alarm circuit; closing the normally open first-mentioned switch; and checking the alarm circuit output.
  • FIG. 1 a basic circuit comprising a switch S and a device embodying the invention connected in parallel therewith between points A and B.
  • the switch S is closed and the load L draws current from A to B through this switch.
  • the device comprises, connected in sequence, a control transistor T2, connection point C, a diode Dl, connection point D, and isolating diode D2.
  • Transistor T2 and diode Dl cause such a voltage drop as to produce a reduced potential in the circuit whereby current is prevented from flowing through isolating diode D2.
  • transistor Tl does not conduct.
  • the device of course can still be controlled by means of light emitting diode LED2 and transistor T2, and therefore if it is necessary for the load to be - switched off, this can be easily accomplished.
  • a similar device for protection of a similar switch connected in the return path from the load L can be provided by reversing the diodes and using negative equivalents of the transistors.
  • connection point D can be connected to an auxiliary supply bus ASB, from which connections can be taken to a number of isolating diodes, D2(a) and D2 (b) for example, each of which isolating diodes protects a switch S(a), S(b) respectively.
  • a single device may protect a number of switches, each controlling a load.
  • Each load has two individual control outputs, one in its supply path, and one in its return path.
  • the common part of the supply path and the common part of the return path are each provided with a separate protection device connected respectively to the auxiliary supply bus ASB and the auxiliary return bus ARB.
  • the device can also be used to test whether or not the switches are working. In the case of a normally closed switch, the switch is opened and the alarm circuit will give an output when the current bypasses the switch to flow through the protection device.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Security & Cryptography (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Keying Circuit Devices (AREA)
  • Testing Electric Properties And Detecting Electric Faults (AREA)
EP19810305812 1980-12-09 1981-12-09 Circuit de protection d'un courant de charge Expired EP0054407B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB8039358 1980-12-09
GB8039358A GB2089591B (en) 1980-12-09 1980-12-09 Switch protection device

Publications (2)

Publication Number Publication Date
EP0054407A1 true EP0054407A1 (fr) 1982-06-23
EP0054407B1 EP0054407B1 (fr) 1985-10-23

Family

ID=10517844

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19810305812 Expired EP0054407B1 (fr) 1980-12-09 1981-12-09 Circuit de protection d'un courant de charge

Country Status (3)

Country Link
EP (1) EP0054407B1 (fr)
DE (1) DE3172734D1 (fr)
GB (1) GB2089591B (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ES2253065A1 (es) * 2004-03-22 2006-05-16 Jose Luis Diaz Mejia Dispositivo y metodo de proteccion ampliada de lineas electricas.

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2249840B (en) * 1990-11-13 1995-01-11 Alireza Ghazi Hessami Universal digital input channel

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3179930A (en) * 1961-03-28 1965-04-20 Cutler Hammer Inc Circuit condition indicating systems
US3505664A (en) * 1967-07-07 1970-04-07 Hubbell Inc Harvey Switch condition indicator
US3626248A (en) * 1970-02-06 1971-12-07 Struthers Dunn Contact monitoring system
US4191946A (en) * 1977-10-20 1980-03-04 Gonzalez Raymond J Warning apparatus with a line integrity supervisory circuit

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3179930A (en) * 1961-03-28 1965-04-20 Cutler Hammer Inc Circuit condition indicating systems
US3505664A (en) * 1967-07-07 1970-04-07 Hubbell Inc Harvey Switch condition indicator
US3626248A (en) * 1970-02-06 1971-12-07 Struthers Dunn Contact monitoring system
US4191946A (en) * 1977-10-20 1980-03-04 Gonzalez Raymond J Warning apparatus with a line integrity supervisory circuit

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ES2253065A1 (es) * 2004-03-22 2006-05-16 Jose Luis Diaz Mejia Dispositivo y metodo de proteccion ampliada de lineas electricas.

Also Published As

Publication number Publication date
GB2089591B (en) 1985-05-22
GB2089591A (en) 1982-06-23
DE3172734D1 (en) 1985-11-28
EP0054407B1 (fr) 1985-10-23

Similar Documents

Publication Publication Date Title
CN101305439B (zh) 用于防故障地关断电消耗装置的安全开关装置
US5343192A (en) Fuse or circuit breaker status indicator
EP0241270B1 (fr) Circuit de surveillance autotesté
US4496941A (en) Switch protection device
US5592373A (en) Method and apparatus for configuring an automation system
EP0054407A1 (fr) Circuit de protection d'un courant de charge
US4706155A (en) Restraint signal interface circuit
US5008655A (en) Visual alarm device interconnectable to existing monitoring circuitry
GB2210521A (en) Electrical safety barrier
US3254331A (en) Alarm annunciator with independent acknowledgement indication
SU1332442A2 (ru) Устройство дл контрол исправности релейной защиты
US4831511A (en) Microcomputer implemented control device with maintenance provisions
SU1013864A1 (ru) Устройство дл индикации наличи напр жени в цеп х посто нного тока
SU1379829A1 (ru) Устройство дл контрол исправности релейной защиты
JPH05216501A (ja) デジタル制御装置の出力回路
JPH11111472A (ja) 灯火器断芯検出装置
SU1644252A1 (ru) Устройство дл контрол исправности релейной защиты
SU1149327A1 (ru) Устройство дл контрол исправности релейной защиты
SU1636784A1 (ru) Устройство дл индикации отсутстви напр жени
SU1591099A1 (ru) Устройство для контроля исправности релейной зашиты
EP0143649A2 (fr) Aménagement de station extérieure pour système électrique de véhicule
SU638999A1 (ru) Устройство дл проверки исправности сигнальных ламп
SU507861A1 (ru) Устройство дл допускового контрол
RU1478884C (ru) Устройство для проверки аппаратуры релейной защиты и автоматики
SU1125670A1 (ru) Устройство дл контрол исправности быстродействующей защиты сети переменного тока

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Designated state(s): BE DE FR IT NL SE

17P Request for examination filed

Effective date: 19821216

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: RESTBURY LIMITED

ITF It: translation for a ep patent filed

Owner name: BARZANO' E ZANARDO ROMA S.P.A.

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Designated state(s): BE DE FR IT NL SE

REF Corresponds to:

Ref document number: 3172734

Country of ref document: DE

Date of ref document: 19851128

ET Fr: translation filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 19881231

Year of fee payment: 8

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: SE

Payment date: 19890314

Year of fee payment: 8

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19890315

Year of fee payment: 8

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 19890320

Year of fee payment: 8

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: BE

Payment date: 19890412

Year of fee payment: 8

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Effective date: 19891210

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: BE

Effective date: 19891231

BERE Be: lapsed

Owner name: RESTBURY LTD

Effective date: 19891231

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Effective date: 19900701

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Effective date: 19900831

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19900901

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

EUG Se: european patent has lapsed

Ref document number: 81305812.0

Effective date: 19900829