TECHNICAL FIELD
[0001] The invention concerns in general the technical field of elevator solutions. Especially
the invention concerns maintenance of electrical conductivity in the elevator solutions.
BACKGROUND
[0002] Electrical contacts have wide range of application areas, wherein is a need to pass
electrical current in a controlled manner from a first conductive material, such as
metal, to another conductive material. The control may e.g. be achieved by adjusting
a gap between the first and the other conductive material. Commonly known electrical
contacts are e.g. electrical switches, relays and breakers. Typical contact material,
in turn, is silver or a silver alloy having small amounts of nickel or copper therein,
for example.
[0003] In elevator systems there are many application areas for the electrical contacts.
Most common areas relate to safety supervision, power switches and different kinds
of electro-mechanical interfaces. The electrical contacts especially in the safety
area, and thus in safety circuits, have to meet many special requirements in order
to maintain the safety in a use of elevators. A fault in a safety related electrical
contact may e.g. stop the elevator and/or cause cancellation of position information
which result delays in the operation.
[0004] At least one root cause for failures in the electrical contacts is degradation of
conductive properties of the material used in the electrical contact or contacts.
The degradation may originate from a contamination of the contact surfaces with foreign
substances, such as dust and/or chemical vapors. The contamination may at least partially
be prevented by ensuring that the air in the electrical contact space is as clean
as possible. However, it is not possible to fully prevent the contamination of the
contact surfaces. Then the question is if the electrical contacts shall be replaced
with new ones or if they shall be cleaned in one way or another. Both these options
generate costs in the use of elevators, which is not desirable. For this reason there
already exist some technical solutions for cleaning the electrical contacts.
[0005] At least some prior art solutions are based on an idea to purge the foreign substances
at least partially from the contact surfaces in the elevator systems by providing
an electrical pulse to the electrical contact in question. The electrical pulse is
generated by providing a high voltage or current to the contact. The drawback in the
use of high voltage, such as 230 VAC, is a risk to get an electric shock from there
e.g. when service personnel is making maintenance operations to the elevator. Use
of high current, in turn, has a disadvantage that it heats the components and energy
consumption is high. The use of high voltage and/or current also requires that used
components are matched to such voltage/current levels, which typically means that
the components are big in size which forces to implement the circuits in large circuit
boards. This is not desirable due to limited space in elevator systems. Besides, use
of high voltage in safety circuits, wherein the electrical contacts typically exist,
require further safety circuits, such as residual-current devices (RCD), in order
to fulfill standards existing in the technology area.
[0007] The document
WO 2011/133163 A1 discloses one solution by means of any contamination in contacts of an elevator safety
circuit may be removed. This is done by providing voltage pulse having an appropriate
voltage level to the contacts.
[0008] The document
US 6800965 B1, in turn, discloses a prior art solution for improving a power consumption of a switch
input circuit. The document discloses a concept of wetting circuit which may be used
for cleaning contacts in the circuit.
[0009] Further, the document
DE 19513615 A1 discloses a contact detector for detecting an open and closed state of an electrical
contact in which alternating current is used for achieving information if a certain
contact is in open or closed state even if abrasion or corrosion is occurred in the
electrical contact.
[0010] The document
US 2005/231876 A1 discusses on a utilization of corrosion-prevention current for maintaining contact
resistance low in a contact. Hence, there is need to develop solutions which at least
partially mitigate the drawbacks of the existing solutions.
SUMMARY
[0011] The following presents a simplified summary in order to provide basic understanding
of some aspects of various invention embodiments. The summary is not an extensive
overview of the invention. The following summary merely presents some concepts of
the invention in a simplified form as a prelude to a more detailed description of
exemplifying embodiments of the invention.
[0012] An objective of the invention is to present an arrangement and a method for at least
partially prevent degradation of conductive properties in material used in electrical
contact or contacts. Another objective of the invention is that the arrangement and
the method provide a mechanism to purge the electrical contact or contacts at least
partly.
[0013] The objectives of the invention are reached by an arrangement and a method as defined
by the respective independent claims.
[0014] According to the invention, an arrangement for purging at least one electrical contact
of an elevator safety circuit is provided, wherein the arrangement comprising: at
least one electrical contact comprising a first contact point and a second contact
point coupled to a control unit in the first contact point and to a load in the second
contact point, wherein the electrical contact is configured to establish a conductive
path across the contact points when the first contact point and the second contact
point are in electrically conductive contact with each other and to interrupt a conductive
path across the contact points when the first contact point and the second contact
point are separated; a capacitor coupled between the second contact point of the electrical
contact and a third voltage, V3; wherein the control unit is configured to selectively
introduce a first voltage, V1, and a second voltage, V2, to the electrical contact
at a high frequency, such as 1000 Hz.
[0015] The control circuit in the arrangement may be configured to determine a voltage difference
over the at least one electrical contact when the first contact point and the second
contact point are in electrically conductive contact and either the first voltage,
V1, or the second voltage, V2, is introduced to the at least one electrical contact.
The control circuit may also be configured to selectively introduce the first voltage
and the second voltage in response to a detection that the voltage difference over
the at least one electrical contact exceeds a predetermined limit.
[0016] The control circuit may also be configured to receive an indication of an operational
state of an entity wherein the safety circuit is arranged in order to determine a
need for selectively introducing the first voltage, V1, and the second voltage, V2,
to the electrical contact.
[0017] According to the invention, a method for purging at least one electrical contact
of an elevator safety circuit is provided, wherein the safety circuit comprising:
a control unit; at least one electrical contact comprising a first contact point and
a second contact point coupled to a control unit in the first contact point and to
a load in the second contact point, wherein the electrical contact is configured to
establish a conductive path across the contact points when the first contact point
and the second contact point are in electrically conductive contact with each other
and to interrupt a conductive path across the contact points when the first contact
point and the second contact point are separated; a capacitor coupled between the
second contact point of the electrical contact and a third voltage, V3; wherein the
method comprising: selectively introducing a first voltage, V1, and a second voltage,
V2, to the electrical contact at a high frequency, such as 1000 Hz, by the control
unit.
[0018] The method may further comprise, prior to the selectively introducing the first voltage,
V1, and the second voltage, V2, to the electrical contact by the control unit, a step
of determining a need for selectively introducing the first voltage, V1, and the second
voltage, V2, to the electrical contact. The determination may comprise steps of: determining
a voltage difference over the at least one electrical contact when the first contact
point and the second contact point are in electrically conductive contact and either
the first voltage, V1, or the second voltage, V2, is introduced to the at least one
electrical contact; and triggering of selective introduction of the first voltage
and the second voltage to the electrical contact in response to a detection that the
voltage difference over the at least one electrical contact exceeds a predetermined
limit.
[0019] The method may further comprise: receiving, in the control unit, an indication of
an operational state of an entity wherein the safety circuit is arranged to in order
to determine a need for selectively introducing the first voltage, V1, and the second
voltage, V2, to the electrical contact.
[0020] Various exemplifying and non-limiting embodiments of the invention both as to constructions
and to methods of operation, together with additional objects and advantages thereof,
will be best understood from the following description of specific exemplifying and
non-limiting embodiments when read in connection with the accompanying drawings.
[0021] The verbs "to comprise" and "to include" are used in this document as open limitations
that neither exclude nor require the existence of unrecited features. The features
recited in dependent claims are mutually freely combinable unless otherwise explicitly
stated. Furthermore, it is to be understood that the use of "a" or "an", i.e. a singular
form, throughout this document does not exclude a plurality.
BRIEF DESCRIPTION OF FIGURES
[0022] The embodiments of the invention are illustrated by way of example, and not by way
of limitation, in the figures of the accompanying drawings.
Figure 1 illustrates schematically an arrangement according to an embodiment of the
invention.
Figure 2 illustrates schematically an arrangement according to another embodiment
of the invention.
Figure 3 illustrates schematically an arrangement according to a still further embodiment
of the invention.
Figure 4 illustrates schematically a method according to an embodiment of the invention.
Figure 5 illustrates schematically a method according to another embodiment of the
invention.
DETAILED DESCRIPTION
[0023] The present invention relates to a solution for purging at least one electrical contact
in an elevator safety circuit. An example of such an arrangement is schematically
illustrated in Figure 1. The arrangement comprises at least one electrical contact
110 comprising a first contact point 112 and a second contact point 114. The at least
one electrical contact is coupled to a control unit 120 in the first contact point
112 and to a load 130 in the second contact point 114. The load may be, but is not
limited to, an electric motor providing power to an entity, such as a door, in the
elevator. The load may also be a measuring device configured to monitor certain parameter
in the elevator and/or a voltage meter arranged to measure voltage level on the second
side of the elevator contact. The electrical contact 110 is configured to establish
a conductive path across the contact points 112, 114 when the first contact point
112 and the second contact point 114 are in electrically conductive contact with each
other and to interrupt a conductive path across the contacts 112, 114 when the first
contact point 112 and the second contact point 114 are separated i.e. the electrically
conductive contact is broken. The control unit 120 is configured at least to control
input of two voltage levels V1, V2 differing from each other to the electrical contact
110. The control of input refers to a provision of the voltages V1 and V2 to the electrical
contact 110. Hence, the control unit 120 may be implemented so that there may be arranged
two electrical components to operate as controllable switches, which are alternatively
conducting. As a result either the voltage V1 or the voltage V2 is brought to the
electrical contact 110. The electrical components may e.g. be, but are not limited
to, FET (Field Effect Transistor) based switches. Furthermore, the arrangement in
the elevator safety circuit comprises a capacitor coupled between the second contact
114 and a third voltage V3. A capacitance of the capacitor 140 is advantageously selected
so that the current for the 130 load is applicable in a frequency the voltages V1
and V2 are selectively input to the electrical contact 110. The voltage level V3 is
selected so that the charging of the capacitor 140 may be adjusted to the application
area.
[0024] Next the operation of the arrangement as illustrated in Figure 1 is described. As
already mentioned the control unit 120 is configured to control the input of the voltages
V1 and V2 in a predetermined frequency to the electrical contact 110. Advantageously,
the electrical contact 110 is arranged in electrically conductive state when the voltages
V1 and V2 are input. The input of the voltages V1 and V2 causes the capacitor 140
to charge and the current input to the load 130 is dependent on the capacitance of
the capacitor 140 and the frequency used for inputting the voltages V1 and V2 in the
arrangement. The frequency in which the voltages V1 and V2 are selectively input to
the electrical contact 110 shall be high, such as 1000 Hz, in order to achieve desired
effect. The desired effect is that at least part of contamination, such as dust and/or
chemical vapors, formed on the surfaces of the first contact point 112 and the second
contact point 114 may be purged. The purge is based on a phenomenon in which the input
voltages V1 and V2 and their switching frequency cause heating of the electrical contact,
i.e. the first and the second contact points 112, 114, when they are in electrically
conductive state. Now, the foreign substances, such as impurities, on the surfaces
of the electrical contacts get also heated in response to applying voltages V1 and
V2 at high frequency to the electrical contact 110 and this causes at least partial
purging of the electrical contact from impurities. This is because dielectric dissipation
factor is the higher the higher the frequency in which the voltage is applied to the
material in question i.e. increases heating of the impurities and even at least partial
burning of them apart from the contact surfaces.
[0025] In some implementations, especially in elevator solutions, the safety circuits may
comprise multiple electrical contacts in order to improve safety. The present invention,
as schematically illustrated in Figure 2, may also be applied to in such implementations.
In the implementation of Figure 2 there are multiple electrical contacts 110A, 110B,
110C, e.g. switches, by means of which it is possible control any operation behind
the switches (illustrated as loads 130A, 130B, 130C). The multiple electrical contacts
110A, 110B, 110C may be purged with the present invention by arranging the control
unit 120 to provide voltage levels V1, V2 to all electrical contacts 110A, 110B, 110C.
Furthermore, capacitors 140A, 140B, 140C are arranged to each electrical contact branch
as described. The number of branches is not limited to three, as illustrated in Figure
2, but may vary.
[0026] Some aspects of the present invention relate to determination if the purge of the
electrical contact(s) shall be triggered or not. Namely, it may be advantageous to
purge the electrical contact(s) periodically rather than constantly. The periodic
purging may be established by tying the triggering of the purging to a predetermined
event. According to a first embodiment of the present invention, as it comes to the
triggering of the purging, a measuring device 310, such as voltage meter, is arranged
to determine voltage difference over the electrical contact 110. This is schematically
illustrated in Figure 3. When the electrical contact 110 is set in a conductive state
and the voltage V1 is input to the electrical contact, it may be determined if there
is voltage difference over the electrical contact 110. In case there is no voltage
difference over the electrical contact, or it is less than a predetermined limit,
it may be concluded that the electrical contact works properly and there is no foreign
substance on the surfaces of the first and/or the second contact point. On the contrary,
if the voltage difference exceeds a predetermined limit, it may be concluded that
there is need to trigger the purging of the electrical contact in the manner as described.
The idea here is that the foreign substance increases resistance in the path which
may be seen as a voltage drop between the measurement points. The determination of
the triggering of the purging may be performed, for example, by a control unit 120
into which measurement data from the measuring device 310 is input. Alternatively
or in addition, a device may be arranged to execute the measurement data analysis
as well as outputting instructions for the control unit 120 in order to perform the
purging.
[0027] Furthermore, the triggering of the purging may be arranged to be dependent on some
predetermined event originating from a device or a system in which the safety circuit
is implemented. The purpose is to detect a conductive state of the electrical contact(s)
in order to provide a purging signal, i.e. alternating current AC, to the electrical
contact(s) at that time. For example, in a context of door solutions in which the
electrical contacts of the doors are in conducting state when a door is closed and
in non-conducting state when the door is open. Hence, the control unit may be configured
to monitor door status, i.e. if the door is open or closed, and based on this information
trigger the purging of the electrical contacts in such instant of time that the electrical
contact 110 is in a conductive state.
[0028] Moreover, the provision of voltages V1 and V2, i.e. the purging signal, may also
be implemented so that the control unit 120 is configured to provide the purging signal
for a predetermined period of time to the electrical contact 110. The period of time
may be determined in a control unit 120 with a timer implementation, which timer is
initiated to run when the purging signal is input to the electrical contact 110. Additionally,
the control unit may receive information from an external entity, such as a sensor,
on an operational state of the electrical contact 110. Then the control unit 120 may
be configured to trigger the control signal with a pre-condition that the electrical
contact 110 is in a conductive state. According to still further embodiment the control
unit 120 may be configured to control the electrical contact(s) 110 in order to initiate
the purging. This may e.g. be arranged so that the control unit 120 is arranged to
be a slave for some master unit which operates the entity marked as load in the figures.
When the master unit is not operating, e.g. not controlling, the load, it may deliver
an indication signal to the control unit 120 and authorize the control unit 120 to
control the electrical contacts, or any elements driving the electrical contacts to
open and closed states, in order to perform the purging.
[0029] Figure 4 illustrates schematically a method according to an embodiment of the invention.
In the method a first voltage, V1, and a second voltage, V2, are selectively introduced
410 to at least one electrical contact 110 by a control unit 120 as described. In
some further embodiment, as schematically illustrated in Figure 5, the method may
comprise a step of determining 510 if there is a need for purging the one or more
electrical contacts in the elevator safety circuit. The determination may comprise
a measurement of a parameter by means of which it is possible to make a decision if
the surfaces of the contact points in the electrical contact are at least partly covered
with impurities or not. Such a parameter may be a voltage over the electrical contact,
as already described. Additionally, the determination may also comprise an analysis
of the measured parameter in order to determine if there is need for purging. According
to some other embodiment of the invention the determination may comprise a monitoring
of a certain event relating to the safety circuit. For example, it may comprise a
determination of an operational state of the safety circuit or an entity into which
the safety circuit is arranged. The triggering, i.e. introduction of the first and
the second voltages to the at least one electrical contact, is initiated in response
to a detection that the operational state meets a predetermined criterion or criteria.
Moreover, the determination of a need for purging may also comprise a step to confirm
that the at least one electrical contact is in an electrically conductive state.
[0030] Advantageously, the voltage levels V1 and V2 are selected so that the voltage level
of the AC current generated through selective introduction of the first and the second
voltages to the electrical contact is 50 V in maximum. This meets extra low voltage
limit defined for elevator solutions and thus mitigates need to implement additional
safety solutions in order to handle any high currents possibly generated in the safety
circuit. Moreover, the AC current used in safety circuits is typically around 100
mA, which may be at least partly achieved in the present invention by optimal selection
of the capacitor in the circuit.
[0031] As may be understood from the description the capacitor or the capacitors operates
in the circuit so that it, or they, generates high current, such as 20...1000 mA,
to the electrical contact with the AC current. Naturally, the capacitor functions
also as a filter towards the load. As said the advantage of the invention is that
the implementation generates an applicable current for achieving the advantages of
the present invention without using high voltages. A rating of the capacitor is at
least partly dependent on a rise time of the voltage which, in turn, is at least partly
dependent on internal resistances of components and any external current limiting
resistances if used, among other possible reasons. As a non-limiting example of a
capacitance value of an applicable capacitor with 50 µs rise time is 1 µF and such
a capacitance generates a current peak of ∼0,5 A. The voltage levels of the first,
second and third voltages may e.g. be the following: V1=24 V, V2=0/24 V, V3=0/24V.
[0032] The specific examples provided in the description given above should not be construed
as limiting the applicability and/or the interpretation of the appended claims. Lists
and groups of examples provided in the description given above are not exhaustive
unless otherwise explicitly stated.
1. An arrangement for purging at least one electrical contact of an elevator safety circuit,
the at least one electrical contact (110) comprises a first contact point (112) and
a second contact point (114), wherein the arrangement comprises:
a control unit (120), the control unit (120) being coupled to the at least one electrical
contact (110) in the first contact point (112), the electrical contact (110) is configured
to establish a conductive path across the contact points (112; 114) when the first
contact point (112) and the second contact point (114) are in electrically conductive
contact with each other and to interrupt a conductive path across the contact points
(112; 114) when the first contact point (112) and the second contact point (114) are
separated,
characterized in that the arrangement further comprises a capacitor (140) coupled between the second contact
point (114) of the electrical contact (110) and a third voltage (V3),
wherein the control unit (120) is configured to selectively introduce a first voltage
(V1) and a second voltage (V2) to the electrical contact (110) at a high frequency,
such as 1000 Hz.
2. The arrangement according to the claim 1, wherein the control unit (120) is configured
to determine a voltage difference over the at least one electrical contact (110) when
the first contact point (112) and the second contact point (114) are in electrically
conductive contact and either the first voltage (V1) or the second voltage (V2) is
introduced to the at least one electrical contact (110).
3. The arrangement according to the claim 2, wherein the control unit (120) is configured
to selectively introduce the first voltage (V1) and the second voltage (V2) in response
to a detection that the voltage difference over the at least one electrical contact
(110) exceeds a predetermined limit.
4. The arrangement according to any of the preceding claims, wherein the control unit
(120) is configured to receive an indication of an operational state of an entity
wherein the safety circuit is arranged in order to determine a need for selectively
introducing the first voltage (V1) and the second voltage (V2) to the electrical contact
(110).
5. A method for purging at least one electrical contact of an elevator safety circuit,
the at least one electrical contact (110) comprises a first contact point (112) and
a second contact point (114), wherein the method is implemented with an arrangement
comprising:
- a control unit (120), the control unit (120) being coupled to the at least one electrical
contact (110) in the first contact point (112), the electrical contact (110) is configured
to establish a conductive path across the contact points (112; 114) when the first
contact point (112) and the second contact point (114) are in electrically conductive
contact with each other and to interrupt a conductive path across the contact points
(112; 114) when the first contact point (112) and the second contact point (114) are
separated,
characterized in that the arrangement comprises a capacitor (140) coupled between the second contact point
(114) of the electrical contact (110) and a third voltage (V3), and
in that the method comprises:
- selectively introducing (410) a first voltage (V1) and a second voltage (V2) to
the electrical contact (110) at a high frequency, such as 1000 Hz, by the control
unit (120).
6. The method according to claim 5, the method further comprising, prior to the selectively
introducing the first voltage (V1) and the second voltage (V2) to the electrical contact
(110) by the control unit (120), a step of determining (510) a need for selectively
introducing (410) the first voltage (V1) and the second voltage (V2) to the electrical
contact (110).
7. The method according to claim 6, wherein the determination (510) comprises steps of:
- determining a voltage difference over the at least one electrical contact (110)
when the first contact point (112) and the second contact point (114) are in electrically
conductive contact and either the first voltage (V1) or the second voltage (V2) is
introduced to the at least one electrical contact (110), and
- triggering of selective introduction (410) of the first voltage and the second voltage
to the electrical contact (110) in response to a detection that the voltage difference
over the at least one electrical contact (110) exceeds a predetermined limit.
8. The method according to any of the preceding claims, the method further comprising:
- receiving, in the control unit (110), an indication of an operational state of an
entity wherein the safety circuit is arranged to in order to determine a need for
selectively introducing the first voltage (V1) and the second voltage (V2) to the
electrical contact (110).
1. Anordnung zum Säubern mindestens eines elektrischen Kontakts einer Aufzugssicherheitsschaltung,
wobei der mindestens eine Kontakt (110) einen ersten Kontaktpunkt (112) und einen
zweiten Kontaktpunkt (114) aufweist, wobei die Anordnung Folgendes umfasst:
eine Steuereinheit (120), wobei die Steuereinheit (120) mit dem mindestens einen elektrischen
Kontakt (110) an dem ersten Kontaktpunkt (112) gekoppelt ist, wobei der elektrische
Kontakt (110) ausgelegt ist zum Herstellen eines leitenden Pfads über die Kontaktpunkte
(112; 114), wenn der erste Kontaktpunkt (112) und der zweite Kontaktpunkt (114) in
elektrisch leitendem Kontakt miteinander stehen, und zum Unterbrechen eines leitenden
Pfads über die Kontaktpunkte (112; 114), wenn der erste Kontaktpunkt (112) und der
zweite Kontaktpunkt (114) getrennt sind,
dadurch gekennzeichnet, dass die Anordnung ferner Folgendes umfasst:
einen Kondensator (140), zwischen den zweiten Kontaktpunkt (114) des elektrischen
Kontakts (110) und eine dritte Spannung (V3) geschaltet,
wobei die Steuereinheit (102) ausgelegt ist zum selektiven Anlegen einer ersten Spannung
(V1) und einer zweiten Spannung (V2) an den elektrischen Kontakt (110) mit einer hohen
Frequenz, wie etwa 1000 Hz.
2. Anordnung nach Anspruch 1, wobei die Steuereinheit (120) ausgelegt ist zum Bestimmen
einer Spannungsdifferenz über dem mindestens einen elektrischen Kontakt (110), wenn
der erste Kontaktpunkt (112) und der zweite Kontaktpunkt (114) in elektrisch leitendem
Kontakt stehen und entweder die erste Spannung (V1) oder die zweite Spannung (V2)
an dem mindestens einen elektrischen Kontakt (110) angelegt ist.
3. Anordnung nach Anspruch 2, wobei die Steuereinheit (120) ausgelegt ist zum selektiven
Anlegen der ersten Spannung (V1) und der zweiten Spannung (V2) als Reaktion auf eine
Detektion, dass die Spannungsdifferenz über dem mindestens einen elektrischen Kontakt
(110) eine vorbestimmte Grenze übersteigt.
4. Anordnung nach einem der vorhergehenden Ansprüche, wobei die Steuereinheit (120) ausgelegt
ist zum Empfangen einer Anzeige eines Betriebszustands einer Entität, wobei die Sicherheitsschaltung
dafür eingerichtet ist, eine Notwendigkeit für selektives Anlegen der ersten Spannung
(V1) und der zweiten Spannung (V2) an den elektrischen Kontakt (110) zu bestimmen.
5. Verfahren zum Säubern mindestens eines elektrischen Kontakts einer Aufzugssicherheitsschaltung,
wobei der mindestens eine elektrische Kontakt (110) einen ersten Kontaktpunkt (112)
und einen zweiten Kontaktpunkt (114) aufweist, wobei das Verfahren mit einer Anordnung
implementiert ist, die Folgendes umfasst:
- eine Steuereinheit (120), wobei die Steuereinheit (120) mit dem mindestens einen
elektrischen Kontakt (110) an dem ersten Kontaktpunkt (112) gekoppelt ist, wobei der
elektrische Kontakt (110) ausgelegt ist zum Herstellen eines leitenden Pfads über
die Kontaktpunkte (112; 114), wenn der erste Kontaktpunkt (112) und der zweite Kontaktpunkt
(114) in elektrisch leitendem Kontakt miteinander stehen, und zum Unterbrechen eines
leitenden Pfads über die Kontaktpunkte (112; 114), wenn der erste Kontaktpunkt (112)
und der zweite Kontaktpunkt (114) getrennt sind,
dadurch gekennzeichnet, dass die Anordnung Folgendes umfasst:
einen Kondensator (140), zwischen den zweiten Kontaktpunkt (114) des elektrischen
Kontakts (110) und eine dritte Spannung (V3) geschaltet,
und dass das Verfahren Folgendes umfasst:
- selektives Anlegen (410) einer ersten Spannung (V1) und einer zweiten Spannung (V2)
an den elektrischen Kontakt (110) mit einer hohen Frequenz, wie etwa 1000 Hz, durch
die Steuereinheit (120).
6. Verfahren nach Anspruch 5, wobei das Verfahren ferner, vor dem selektiven Anlegen
der ersten Spannung (V1) und der zweiten Spannung (V2) an den elektrischen Kontakt
(110) durch die Steuereinheit (120), einen Schritt des Bestimmens (510) einer Notwendigkeit
für selektives Anlegen (410) der ersten Spannung (V1) und der zweiten Spannung (V2)
an den elektrischen Kontakt (110) umfasst.
7. Verfahren nach Anspruch 6, wobei die Bestimmung (510) die folgenden Schritte umfasst:
- Bestimmen einer Spannungsdifferenz über dem mindestens einen elektrischen Kontakt
(110), wenn der erste Kontaktpunkt (112) und der zweite Kontaktpunkt (114) in elektrisch
leitendem Kontakt stehen und entweder die erste Spannung (V1) oder die zweite Spannung
(V2) an dem mindestens einen elektrischen Kontakt (110) angelegt ist, und
- selektives Anlegen (410) der ersten Spannung und der zweiten Spannung an den elektrischen
Kontakt (110), als Reaktion auf eine Detektion, dass die Spannungsdifferenz über dem
mindestens einen elektrischen Kontakt (110) eine vorbestimmte Grenze übersteigt.
8. Verfahren nach einem der vorhergehenden Ansprüche, wobei das Verfahren ferner umfasst:
- Empfangen, in der Steuereinheit (110), einer Anzeige eines Betriebszustands einer
Entität, wobei die Sicherheitsschaltung dafür eingerichtet ist, eine Notwendigkeit
für selektives Anlegen der ersten Spannung (V1) und der zweiten Spannung (V2) an den
elektrischen Kontakt (110) zu bestimmen.
1. Agencement destiné à purger au moins un contact électrique d'un circuit de sécurité
d'ascenseur, l'au moins un contact électrique (110) comprenant un premier point de
contact (112) et un deuxième point de contact (114), l'agencement comprenant :
une unité de commande (120), l'unité de commande (120) étant couplée à l'au moins
un contact électrique (110) dans le premier point de contact (112), le contact électrique
(110) étant configuré pour établir un chemin conducteur passant par les points de
contact (112 ; 114) quand le premier point de contact (112) et le deuxième point de
contact (114) sont en contact électriquement conducteur l'un avec l'autre et pour
interrompre un chemin conducteur passant par les points de contact (112 ; 114) quand
le premier point de contact (112) et le deuxième point de contact (114) sont séparés,
caractérisé en ce que l'agencement comprend en outre
un condensateur (140) couplé entre le deuxième point de contact (114) du contact électrique
(110) et une troisième tension (V3),
dans lequel l'unité de commande (120) est configurée pour introduire sélectivement
une première tension (V1) et une deuxième tension (V2) dans le contact électrique
(110) à une fréquence élevée, telle que 1000 Hz.
2. Agencement selon la revendication 1, dans lequel l'unité de commande (120) est configurée
pour déterminer une différence de tension sur l'au moins un contact électrique (110)
quand le premier point de contact (112) et le deuxième point de contact (114) sont
en contact électriquement conducteur et soit la première tension (V1), soit la deuxième
tension (V2) est introduite dans l'au moins un contact électrique (110).
3. Agencement selon la revendication 2, dans lequel l'unité de commande (120) est configurée
pour introduire sélectivement la première tension (V1) et la deuxième tension (V2)
en réponse à une détection que la différence de tension sur l'au moins un contact
électrique (110) dépasse une limite prédéterminée.
4. Agencement selon l'une quelconque des revendications précédentes, dans lequel l'unité
de commande (120) est configurée pour recevoir une indication d'un état opérationnel
d'une entité, le circuit de sécurité étant agencé afin de déterminer un besoin d'introduire
sélectivement la première tension (V1) et la deuxième tension (V2) dans le contact
électrique (110).
5. Procédé destiné à purger au moins un contact électrique d'un circuit de sécurité d'ascenseur,
l'au moins un contact électrique (110) comprenant un premier point de contact (112)
et un deuxième point de contact (114), le procédé étant mis en oeuvre avec un agencement
comprenant :
- une unité de commande (120), l'unité de commande (120) étant couplée à l'au moins
un contact électrique (110) dans le premier point de contact (112), le contact électrique
(110) étant configuré pour établir un chemin conducteur passant par les points de
contact (112 ; 114) quand le premier point de contact (112) et le deuxième point de
contact (114) sont en contact électriquement conducteur l'un avec l'autre et pour
interrompre un chemin conducteur passant par les points de contact (112 ; 114) quand
le premier point de contact (112) et le deuxième point de contact (114) sont séparés,
caractérisé en ce que l'agencement comprend
un condensateur (140) couplé entre le deuxième point de contact (114) du contact électrique
(110) et une troisième tension (V3),
et
en ce que le procédé comprend :
- l'introduction sélective (410) d'une première tension (V1) et d'une deuxième tension
(V2) dans le contact électrique (110) à une fréquence élevée, telle que 1000 Hz, par
l'unité de commande (120).
6. Procédé selon la revendication 5, le procédé comprenant en outre, avant l'introduction
sélective de la première tension (V1) et de la deuxième tension (V2) dans le contact
électrique (110) par l'unité de commande (120), une étape de détermination (510) d'un
besoin d'introduire sélectivement (410) la première tension (V1) et la deuxième tension
(V2) dans le contact électrique (110) .
7. Procédé selon la revendication 6, dans lequel la détermination (510) comprend des
étapes de :
- détermination d'une différence de tension sur l'au moins un contact électrique (110)
quand le premier point de contact (112) et le deuxième point de contact (114) sont
en contact électriquement conducteur et soit la première tension (V1), soit la deuxième
tension (V2) est introduite dans l'au moins un contact électrique (110), et
- déclenchement de l'introduction sélective (410) de la première tension et de la
deuxième tension dans le contact électrique (110) en réponse à une détection que la
différence de tension sur l'au moins un contact électrique (110) dépasse une limite
prédéterminée.
8. Procédé selon l'une quelconque des revendications précédentes, le procédé comprenant
en outre :
- la réception, dans l'unité de commande (110), d'une indication d'un état opérationnel
d'une entité, le circuit de sécurité étant agencé afin de déterminer un besoin d'introduire
sélectivement la première tension (V1) et la deuxième tension (V2) dans le contact
électrique (110).