EP1100100A1 - Schaltung zur Zustandserkennung eines elektrischen Schalters - Google Patents

Schaltung zur Zustandserkennung eines elektrischen Schalters Download PDF

Info

Publication number
EP1100100A1
EP1100100A1 EP00124515A EP00124515A EP1100100A1 EP 1100100 A1 EP1100100 A1 EP 1100100A1 EP 00124515 A EP00124515 A EP 00124515A EP 00124515 A EP00124515 A EP 00124515A EP 1100100 A1 EP1100100 A1 EP 1100100A1
Authority
EP
European Patent Office
Prior art keywords
switch
state
signal
switches
control unit
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
EP00124515A
Other languages
English (en)
French (fr)
Other versions
EP1100100B1 (de
Inventor
Allessandro Bergamini
Faustino Brandola
Allessandra Mitidieri Costanza
Marco Morello
William Vigano'
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.)
Marelli Europe SpA
Original Assignee
Magneti Marelli SpA
Magneti Marelli Sistemi Elettronici SpA
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 Magneti Marelli SpA, Magneti Marelli Sistemi Elettronici SpA filed Critical Magneti Marelli SpA
Publication of EP1100100A1 publication Critical patent/EP1100100A1/de
Application granted granted Critical
Publication of EP1100100B1 publication Critical patent/EP1100100B1/de
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H9/00—Details of switching devices, not covered by groups H01H1/00 - H01H7/00
    • H01H9/16—Indicators for switching condition, e.g. "on" or "off"
    • H01H9/167—Circuits for remote indication
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H1/00—Contacts
    • H01H1/0015—Means for testing or for inspecting contacts, e.g. wear indicator

Definitions

  • the present invention relates in general to a circuit for detecting the state of electrical switches.
  • the invention relates to a circuit of the type described in the preamble to Claim 1, for reading the state (open/closed) of electrical switches, particularly for automotive applications, as well as for the diagnosis of a possible damaged condition of the contacts of the switches.
  • Electronic control units provided for managing information connected with the instantaneous states adopted by these switches and for undertaking predetermined actions as a result of a change thereof, are therefore required to monitor these states continuously.
  • Information regarding the instantaneous state of a switch is generally acquired by the provision of a network (for example, this may simply be a resistive divider) which supplies the switch and which detects the voltage established at the terminals of the switch and compares its value with one or more threshold values.
  • a network for example, this may simply be a resistive divider
  • Switches fitted in motor vehicles are generally exposed to moisture, dirt and other atmospheric agents with the result that they undergo damage to their contacts and, in some cases, exhibit a general malfunction condition.
  • an electrical switch which in an open state would have an equivalent resistance of the order of 100 k ⁇ or more may have a greatly reduced equivalent resistance (of the order of a few k ⁇ ) because an undesired current path is established between the contacts.
  • each switch is constantly supplied with a cleaning current of considerable intensity and the value of the voltage which is established at its terminals is transferred to the input of a processing and control unit where it is converted into a digital signal and stored.
  • this method does not permit quantitative diagnosis of a condition of damage to the contacts of the switch, that is, it cannot recognize whether a certain voltage value at the terminals of the switch results from a corresponding actual operative state or from a condition of excessive damage.
  • control unit In all of these cases it would instead be preferable, in the absence of events, for the control unit to operate in an operative state of low current consumption, for example, in order not to discharge the battery of the vehicle, but to be able to recognize correctly the operative state of a switch and/or a possible malfunction condition thereof.
  • the object of the present invention is therefore to provide a satisfactory solution to the problems set out above, preventing the problems of the prior art. According to the present invention, this object is achieved by means of a circuit having the characteristics recited in Claim 1.
  • the present invention is based on the principle of supplying the switches continuously with a monitoring current of low intensity so as to satisfy the requirements of low consumption and, selectively, in dependence on the detection of a presumed change in the state of a switch, with a diagnosis current of greater intensity in order to check that the event has actually occurred or to reveal a condition of damage to the switch.
  • the supply of the monitoring current permits continuous monitoring of the state of a switch and qualitative recognition of cases in which the switch has a low or almost zero equivalent resistance (and hence a voltage below a first predetermined threshold value at its terminals) or a very high equivalent resistance (and hence a voltage above a second predetermined threshold value at its terminals).
  • a low or almost zero equivalent resistance may be due to the closed state of the switch, but also to a condition of damage thereto which is present in an open state, when the control unit recognizes that this situation has arisen, the control unit is arranged to supply the diagnosis current and to take a further reading of the state of the switch.
  • the network for supplying the switches includes, for each switch, a pair of circuit branches, each of which is supplied by a corresponding supply voltage and which, in the currently-preferred embodiment, constitute, with the switches, resistive dividers.
  • the supply voltages and the resistive components of these branches are advantageously selected in a manner such that, for a equivalent resistance value which is typical of a condition of damage to the switch so that this condition is interpreted as a closed state of the switch when it is supplied solely with the monitoring current, the supply by means of the diagnosis current enables the open state of the switch to be detected correctly, thus giving rise to two different readings.
  • the supply voltages and the resistive components of the supply network are also advantageously selected in a manner such that the closed state of a switch and the open state in an undamaged condition are interpreted in the same manner in both supply situations.
  • the control unit is then arranged to warn the user of the vehicle of the appearance of a malfunction condition when there are differing readings, and to undertake cyclically a checking procedure to ascertain whether a correct operating condition has been re-established.
  • the switches are also connected to a microprocessor control unit P via respective connection lines, for example, for the switches SW 1 and SW 2 , the lines 10, 20 each of which is connected at one end to the corresponding node N i and at the other end to an activation input IRQ i and to a reading input RD i of the control unit P.
  • the supply network includes first and second circuit branches connected to each switch via the respective node N i and supplied by means of corresponding terminals VS 1 and VS 2 , respectively.
  • a first supply circuit branch B 1 to the supply terminal VS 1 of which a first supply voltage V cc is applied, comprises a resistor R 1 interposed between the supply terminal and the node N 1 .
  • a second supply circuit branch B 2 to the supply terminal VS 2 of which a second supply voltage V B is selectively applied comprises a resistor R 2 and a diode D connected in series therewith, with its cathode connected to the node N 1 .
  • the supply terminal VS 2 is connected to a battery B (for example, the 12V battery of the vehicle, in automotive applications) by means of the emitter-collector path of a switch Q.
  • a single switch Q is common to all of the second circuit paths B 2 and is formed by a bipolar transistor the base terminal of which is connected to an output EN of the control unit P.
  • the connection of the diodes D in the branches B 2 prevents the monitoring current supplied to the switch SW 2 from flowing from the respective branch B 1 , through the respective branch B 2 and the branch B 2 relating to SW 1 , towards the switch SW 1 , upon closure of the switch SW 1 , confusing the reading of the voltage at the node N 1 .
  • An electrical switch approximates to the behaviour of an ideal switch SW id (short-circuit in a closed state, open circuit in an open state), except for a resistive component in series, indicated R s , which intervenes in a closed state and is of the order of a few tens of ohms (the value typically recognized for an on/off switch or a diverter switch for applications in the automotive field is 25 ⁇ ), and except for a resistive component in parallel, indicated R p which takes account of any parasitic current path between the contacts of the switch due to conditions of wear and dirtiness.
  • the resistive component R p in parallel is of the order of hundreds of k ⁇ ; in a damaged switch, the value typically recognized for the resistive component R p is 2k ⁇ .
  • the supply voltage V cc applied to the terminal VS 1 of the first circuit branch is preferably 5V (and corresponds to the supply voltage of the control unit P), whereas the supply voltage V B applied selectively to the terminal VS 2 of the second circuit branch is derived directly from the battery B (and is therefore about 12V).
  • the values of the resistors R 1 and R 2 are preferably 47k ⁇ and 1k ⁇ , respectively.
  • the signal indicative of the state of a switch is acquired by detecting the voltage which is established at its terminals.
  • each switch SW i is supplied with a monitoring current exclusively via the respective first circuit branch B 1 .
  • the control unit P is therefore able to monitor the (normally open) state of each switch continuously, operating in a state of low current consumption (of the order of hundredths of a mA).
  • the voltage detected at the node N i is determined by the resistive divider constituted by the resistor R 1 and by the equivalent resistance of the switch.
  • the equivalent resistance of a closed switch adopts a value substantially equal to R s (almost zero) and the voltage at the corresponding node N i adopts a value close to the earth potential and in any case within a first range of values or below a predetermined first threshold value.
  • the control unit P receives this voltage value at the corresponding input IRQ i and interprets it as a low logic level binary signal.
  • a monitoring current of the order of a tenth of a mA flows through the switch.
  • the equivalent resistance R p is of the order of hundreds of k ⁇ or more and the supply voltage V cc is divided and is established predominantly at the terminals of the switch.
  • the voltage at the corresponding node N i adopts a value within a second range of values or above a predetermined second threshold value.
  • the control unit P receives this voltage value at the corresponding input IRQ i and interprets it as a high logic level binary signal.
  • a situation of this type also arises when a switch undergoes excessive damage to its contacts and its equivalent resistance R p in the open state adopts a low value (of the order of 2 k ⁇ ) much lower than R 1 .
  • the supply voltage V cc is divided and is established predominantly at the terminals of R 1 and, although the voltage at the node N i is not close to the earth potential, it nevertheless adopts a value within the first range of values or below the first threshold value, which is again interpreted as a low logic level binary signal.
  • control unit Every time the control unit is activated, it is arranged to take a further reading of the state of the switch in order to distinguish which event has actually occurred.
  • the voltage detected at the node N i is now determined substantially by the resistive divider constituted by the emitter-collector path of the switch Q, by the resistor R 2 , by the diode D polarized directly, and by the equivalent resistance of the switch.
  • a diagnosis current of the order of a few mA flows through the switch.
  • the equivalent resistance R p is of the order of one k ⁇ , but is still comparable with R 2 so that the supply voltage V B is divided and is established predominantly at the terminals of the switch and the voltage at the corresponding node N i again adopts a value within the second range of values or above the second threshold value, and the control unit interprets this value correctly as a high logic level binary signal.
  • the control unit correctly recognizes the closed state of the switch and undertakes the predetermined actions resulting from this event.
  • control unit If the control unit has detected a general condition of malfunction of a switch, it warns the user of the vehicle of this condition and is arranged to perform cyclically a checking procedure to ascertain whether a correct operating condition has been re-established.
  • the control unit prevents the supply of the diagnosis current, arranging the network for supplying the switches to operate with the monitoring current alone (switch Q non-conductive). Cyclically, after a waiting period of predetermined duration, it reads the states of the switches at two successive moments by supplying them by means of the monitoring current and by means of the diagnosis current, respectively.
  • the persistence of the malfunction condition is recognized and the unit is arranged for a further diagnosis when a subsequent waiting period has elapsed.
  • the unit advantageously starts to operate in the normal operative condition again, and is set to await an event (supply with low current consumption).
  • the invention is not limited purely to the preferred embodiment described fully by way of example, in which the signal indicative of the state of a switch is acquired by detecting the voltage at the terminals of the switch, but further embodiments in which this signal is acquired at other points of the circuit branches for supplying the switches are also envisaged.
EP00124515A 1999-11-12 2000-11-09 Schaltung zur Zustandserkennung eines elektrischen Schalters Expired - Lifetime EP1100100B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
ITTO990969 1999-11-12
IT1999TO000969A IT1311343B1 (it) 1999-11-12 1999-11-12 Circuito per il rilevamento dello stato di interruttori elettrici.

Publications (2)

Publication Number Publication Date
EP1100100A1 true EP1100100A1 (de) 2001-05-16
EP1100100B1 EP1100100B1 (de) 2006-10-04

Family

ID=11418199

Family Applications (1)

Application Number Title Priority Date Filing Date
EP00124515A Expired - Lifetime EP1100100B1 (de) 1999-11-12 2000-11-09 Schaltung zur Zustandserkennung eines elektrischen Schalters

Country Status (4)

Country Link
EP (1) EP1100100B1 (de)
DE (1) DE60031069T2 (de)
ES (1) ES2267448T3 (de)
IT (1) IT1311343B1 (de)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2841375A1 (fr) * 2002-06-05 2003-12-26 Denso Corp Dispositif de determination d'etat de commutation et procede de determination d'un etat de commutation
US7340437B2 (en) * 2002-09-25 2008-03-04 Nucellsys Gmbh Circuit configuration and method for identifying error situations in interconnected systems
FR3006462A1 (fr) * 2013-05-30 2014-12-05 Continental Automotive France Procede et dispositif de lecture de l'etat de variables de contact d'un vehicule automobile
US9908487B2 (en) 2014-08-05 2018-03-06 Continental Automotive France Method for acquiring signals such as signals representative of the state of contacts of a motor vehicle
FR3080399A1 (fr) * 2018-04-18 2019-10-25 Psa Automobiles Sa Procede de commande d’une serrure electrique permettant de diagnostiquer une defaillance de la commande d’ouverture associee, commande d’ouverture et vehicule mettant en œuvre un tel procede
IT201900006846A1 (it) * 2019-05-15 2020-11-15 Geox Spa Circuito di controllo per un indumento luminoso e metodo di attivazione di sorgenti luminose su indumenti

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105785264B (zh) * 2016-04-25 2018-06-08 首瑞（天津）电气设备有限公司 断路器状态监测装置

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4323890A (en) * 1979-05-22 1982-04-06 Auergesellschaft Gmbh Switching circuit for monitoring the switching state of switch elements
EP0259881A2 (de) * 1986-09-12 1988-03-16 Omron Tateisi Electronics Co. Schaltapparat
EP0301442A2 (de) * 1987-07-28 1989-02-01 Bayerische Motoren Werke Aktiengesellschaft, Patentabteilung AJ-3 Schaltungsanordnung zur Überprüfung der Zuleitungen eines Schalters oder Sensors
DE4015271A1 (de) * 1990-05-12 1991-11-14 Vdo Schindling Schaltungsanordnung zur abfrage von schalterstellungen
US5374922A (en) * 1991-10-15 1994-12-20 Gec Alsthom Sa Device for determining the state of an apparatus, and in particular the open or closed state of an electrical apparatus by means of auxiliary contacts
US5714852A (en) * 1996-09-13 1998-02-03 United Technologies Automotive, Inc. Three state switch detection using current sensing
US5772205A (en) * 1995-10-27 1998-06-30 Coldebella; Mark J. System to detect inoperative switches in an amusement device

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4323890A (en) * 1979-05-22 1982-04-06 Auergesellschaft Gmbh Switching circuit for monitoring the switching state of switch elements
EP0259881A2 (de) * 1986-09-12 1988-03-16 Omron Tateisi Electronics Co. Schaltapparat
EP0301442A2 (de) * 1987-07-28 1989-02-01 Bayerische Motoren Werke Aktiengesellschaft, Patentabteilung AJ-3 Schaltungsanordnung zur Überprüfung der Zuleitungen eines Schalters oder Sensors
DE4015271A1 (de) * 1990-05-12 1991-11-14 Vdo Schindling Schaltungsanordnung zur abfrage von schalterstellungen
US5374922A (en) * 1991-10-15 1994-12-20 Gec Alsthom Sa Device for determining the state of an apparatus, and in particular the open or closed state of an electrical apparatus by means of auxiliary contacts
US5772205A (en) * 1995-10-27 1998-06-30 Coldebella; Mark J. System to detect inoperative switches in an amusement device
US5714852A (en) * 1996-09-13 1998-02-03 United Technologies Automotive, Inc. Three state switch detection using current sensing

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2841375A1 (fr) * 2002-06-05 2003-12-26 Denso Corp Dispositif de determination d'etat de commutation et procede de determination d'un etat de commutation
US7123018B2 (en) 2002-06-05 2006-10-17 Denso Corporation Switching status determination device and method for determining switching status
US7340437B2 (en) * 2002-09-25 2008-03-04 Nucellsys Gmbh Circuit configuration and method for identifying error situations in interconnected systems
FR3006462A1 (fr) * 2013-05-30 2014-12-05 Continental Automotive France Procede et dispositif de lecture de l'etat de variables de contact d'un vehicule automobile
US9266481B2 (en) 2013-05-30 2016-02-23 Continental Automotive France Method and device for reading the state of contact variables of a motor vehicle
US9908487B2 (en) 2014-08-05 2018-03-06 Continental Automotive France Method for acquiring signals such as signals representative of the state of contacts of a motor vehicle
FR3080399A1 (fr) * 2018-04-18 2019-10-25 Psa Automobiles Sa Procede de commande d’une serrure electrique permettant de diagnostiquer une defaillance de la commande d’ouverture associee, commande d’ouverture et vehicule mettant en œuvre un tel procede
IT201900006846A1 (it) * 2019-05-15 2020-11-15 Geox Spa Circuito di controllo per un indumento luminoso e metodo di attivazione di sorgenti luminose su indumenti
WO2020230033A1 (en) * 2019-05-15 2020-11-19 Geox S.P.A. Control circuit for a luminous garment and method for activating light sources on garments
CN113825423A (zh) * 2019-05-15 2021-12-21 健乐士股份公司 用于发光服装的控制电路及用于激活服装上光源的方法

Also Published As

Publication number Publication date
DE60031069T2 (de) 2007-02-08
ITTO990969A1 (it) 2001-05-12
ES2267448T3 (es) 2007-03-16
ITTO990969A0 (it) 1999-11-12
IT1311343B1 (it) 2002-03-12
DE60031069D1 (de) 2006-11-16
EP1100100B1 (de) 2006-10-04

Similar Documents

Publication Publication Date Title
CN109791175B (zh) 半桥驱动器故障诊断系统和方法
US7023215B2 (en) Field effect sensor two wire interconnect method and apparatus
JP3803816B2 (ja) 電子点滅信号発生器
US5448492A (en) Monitoring the characteristics of a load driver controlled by a microcontroller
JP6353648B2 (ja) 半導体異常検出回路
CN108068729B (zh) 包括具有同时开关状态检测功能的多重模拟开关监测系统的车辆
EP1100100B1 (de) Schaltung zur Zustandserkennung eines elektrischen Schalters
US8432060B2 (en) Device for the electric actuation of a safety-critical system
JP4838883B2 (ja) エネルギー源の不足電圧を検出するための回路装置
US20190263335A1 (en) Switching circuit, failure detection method therefor, and control apparatus
JPH01500157A (ja) 自動車の１以上の電気負荷用の回路装置
US7109892B2 (en) Device for activating an electronic control unit
KR100482611B1 (ko) 차량의 회로 이상 검출 시스템 및 방법
US11167646B2 (en) Input fault detection system
US6469545B2 (en) Circuit configuration for detecting the state of at least one electrical actuating element
US6242821B1 (en) CMOS passive input circuit
EP3519238B1 (de) Eine elektronische steuereinheit eines fahrzeug, das mehrfache elektrische laden kontrolliert wird
US20060206762A1 (en) Circuit arrangement, in addition to method for identifying interruptions and short-circuits in coupled systems
KR100207122B1 (ko) 자동차의 운행정보 기록 시스템에서 데이터 안정화장치
JPH0142054Y2 (de)
KR19980060968U (ko) 메모리 백업(Back Up)용 전원공급회로
CN113597741A (zh) 用于检查半导体开关的故障的方法
JPH06230045A (ja) バッテリ電圧低下検出回路

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

Kind code of ref document: A1

Designated state(s): DE ES FR GB

AX Request for extension of the european patent

Free format text: AL;LT;LV;MK;RO;SI

17P Request for examination filed

Effective date: 20011024

AKX Designation fees paid

Free format text: DE ES FR GB

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

Owner name: MAGNETI MARELLI SISTEMI ELETTRONICI S.P.A.

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

RIN1 Information on inventor provided before grant (corrected)

Inventor name: MITIDIERI COSTANZA, ALESSANDRA

Inventor name: BERGAMINI, ALESSANDRO

Inventor name: MORELLO, MARCO

Inventor name: BRANDOLA, FAUSTINO

Inventor name: VIGANO',WILLIAM

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

Owner name: MAGNETI MARELLI SISTEMI ELETTRONICI S.P.A.

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE ES FR GB

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

REF Corresponds to:

Ref document number: 60031069

Country of ref document: DE

Date of ref document: 20061116

Kind code of ref document: P

REG Reference to a national code

Ref country code: ES

Ref legal event code: FG2A

Ref document number: 2267448

Country of ref document: ES

Kind code of ref document: T3

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

Effective date: 20070705

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

Ref country code: GB

Payment date: 20141024

Year of fee payment: 15

Ref country code: ES

Payment date: 20141103

Year of fee payment: 15

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 16

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20151109

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 17

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

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20151109

REG Reference to a national code

Ref country code: ES

Ref legal event code: FD2A

Effective date: 20161229

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

Ref country code: ES

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20151110

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 18

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 19

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

Ref country code: DE

Payment date: 20191021

Year of fee payment: 20

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

Ref country code: FR

Payment date: 20191022

Year of fee payment: 20

REG Reference to a national code

Ref country code: DE

Ref legal event code: R071

Ref document number: 60031069

Country of ref document: DE