AU2019253361B2

AU2019253361B2 - Electronic cut-off device

Info

Publication number: AU2019253361B2
Application number: AU2019253361A
Authority: AU
Inventors: Christophe AMPILHAC
Original assignee: Legrand SNC; Legrand France SA
Current assignee: Legrand SNC; Legrand France SA
Priority date: 2018-04-12
Filing date: 2019-03-13
Publication date: 2024-02-08
Anticipated expiration: 2039-03-13
Also published as: CN111937109B; EP3776617A1; WO2019197740A1; EP3776617C0; BR112020020094A2; CO2020012466A2; CN111937109A; EP3776617B1; AU2019253361A1; FR3080228B1; FR3080228A1

Abstract

The invention concerns an electronic cut-off device (10) comprising a first input terminal (12), a second input terminal (14), a first output terminal (16), a second output terminal (18), a controllable switch (22) inserted between the first input terminal (12) and the first output terminal (16), and a control circuit (20) capable of producing a control signal (S) to be sent to the controllable switch (22). The cut-off device (10) further comprises a measurement circuit (30) for measuring an electrical variable consumed through the controllable switch (22), and a finite impedance circuit (24) inserted between the first output terminal (16) and the second output terminal (18). The control circuit (20) is designed to produce a control signal (S) for opening the controllable switch (22) and for monitoring the measured electrical variable (M) when this opening control signal (S) is produced. A method for detecting a fault in a electronic cut-off device is also described.

Description

ELECTRONIC CUT-OFF DEVICE TECHNICAL FIELD TO WHICH THE INVENTION RELATES

The present invention generally relates to the field of

electronic devices that make it possible selectively to

transmit electrical power to a load, or to switch off the

supply of power to the load.

The invention relates more particularly to an electronic switch-off device comprising a first inlet terminal, a second

inlet terminal, a first outlet terminal, a second outlet

terminal, a controllable switch that is interposed between the

first inlet terminal and the first outlet terminal, and a

control circuit that is adapted to produce a control signal

for the controllable switch.

TECHNOLOGICAL BACKGROUND

Under the control of the control circuit, such an

electronic device makes it possible selectively to apply a

voltage (that is applied across its inlet terminals) to a load

that is connected to its outlet terminals.

The control circuit can determine which control signal is

to be produced (for causing the controllable switch to open or

close) depending on various settings, such as a local setting

(e.g. defined by means of a button provided on the electronic

switch-off device) and/or a remote setting (e.g. received via

a communications circuit), which provides great flexibility of

operation.

However, certain controllable switches used in such

electronic devices can remain stuck in their closed position

even when the control circuit applies an opening control

signal thereto (typically because of a momentary current surge

caused by the load being powered and causing the contacts of

the switching member to become welded or bonded together).

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Document EP 2 879 152 describes a switch-off device for

an AC power supply, the device comprising a relay that is

connected in a power supply line and a detector device for

detecting a welding fault in the relay.

In that document, a potential welding fault is detected

on the basis of the difference in current induced in a

transformer wound with the supply line, depending on whether

or not the relay is welded.

SUMMARY OF THE INVENTION

In this context, an aspect of the present invention

provides an electrical accessory of the switch type comprising

a first inlet terminal, a second inlet terminal, a first

outlet terminal, a second outlet terminal, a controllable

switch that is interposed between the first inlet terminal and

the first outlet terminal, and a control circuit that is

adapted to produce a control signal for the controllable

switch;

wherein said electrical accessory of the switch type

further comprises: a measurement circuit for measuring a

magnitude of the electricity consumed through the controllable

switch; and a finite-impedance circuit that is interposed

between the first outlet terminal and the second outlet

terminal; and in that the control circuit is designed to

produce an opening control signal for opening the controllable

switch, to monitor the measured electrical magnitude when the

opening control signal is produced, and to generate a fault

indication if the measured electrical magnitude indicates non

zero electricity consumption through the controllable switch

when the opening control signal is produced.

The electrical accessory of the switch type may be an

electronic switch-off device.

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By means of the finite-impedance circuit that is interposed between the outlet terminals, some current flows through the controllable switch when said controllable switch is in its closed position, even in the absence of any load connected to the outlet terminals. By means of the measurement circuit, the control circuit can thus detect abnormal closure of the controllable switch (i.e. closure of the controllable switch while the control circuit is generating an opening control signal), and can do so even in the absence of any load. The electronic switch-off device of an embodiment of the invention has other characteristics that, taken individually or in any technically possible combination, are non-limiting and advantageous, and that are as follows: - the control circuit is designed to generate a fault indication if the measured electrical magnitude indicates non zero electricity consumption through the controllable switch when the opening control signal is produced; • the fault indication is switching on an indicator lamp; the fault indication is a lighting control signal for switching on an indicator lamp or it is fault information transmitted to a user terminal; • the electronic switch-off device includes a human machine interface that is designed to transmit local control information to the control circuit; • the electronic switch-off device includes a communications circuit that is designed to transmit remote control information to the control circuit; • the measurement circuit is designed to measure the electric current passing through the controllable switch, said electrical magnitude being said current; and

20499183_1 (GHMatters) P114597.AU the finite-impedance circuit is a resistor that is connected between the first outlet terminal and the second outlet terminal.

Another aspect of the invention proposes a method of

detecting a fault in an electrical accessory of the switch

type comprising a first inlet terminal, a second inlet

terminal, a first outlet terminal, a second outlet terminal, a

controllable switch that is interposed between the first inlet

terminal and the first outlet terminal, and a control circuit

that is adapted to produce a control signal for the

controllable switch, wherein the electrical accessory of the

switch type includes a finite-impedance circuit that is

interposed between the first outlet terminal and the second

outlet terminal, and in that the method comprises the

following steps: measuring a magnitude of the electricity

consumed through the controllable switch;

• the control circuit producing an opening control signal

for opening the controllable switch; monitoring the measured

electrical magnitude when the opening control circuit is

produced; and generating a fault indication if the measured

electrical magnitude indicates non-zero electricity

consumption through the controllable switch when the opening

control signal is produced.

The fault-detection method may further comprise a step of

generating a fault indication if the measured electrical

magnitude indicates non-zero electricity consumption through

the controllable switch when the opening control signal is

produced.

BRIEF DESCRIPTION OF THE DRAWINGS

The following description of non-limiting examples given

with reference to the accompanying drawings, makes it possible

20499183_1 (GHMatters) P114597.AU to understand what the invention consists of and how it can be reduced to practice. In the accompanying drawings: - Figure 1 is an electrical diagram of an electrical system including an electronic switch-off device of an embodiment of the invention; and - Figure 2 is a flowchart showing an example of a method that is implemented within such an electronic switch-off device. DETAILED DESCRIPTION OF EMBODIMENTS Figure 1 shows an electrical system comprising a voltage source (in this embodiment an alternating current (AC) voltage source) 2, a load 4, and an electronic switch-off device 10 that is interposed between the voltage source 2 and the load 4. By way of example, such an electronic switch-off device 10 is an electrical switch (i.e. an electrical accessory of the switch type) for flush mounting in a wall or for mounting on a wall. In this embodiment, the voltage source 2 is typically an electricity network supplying a building (e.g. a residence) and applying, across two power supply terminals L, N, a "mains" AC voltage having characteristics that are defined by the applicable regulations (e.g. a nominal root mean square (rms) voltage of 230 volts (V) and a frequency of 50 hertz (Hz). In this context, the power supply terminal L is the line terminal, while the power supply terminal N is the neutral terminal. By way of example, the load 4 is a lamp (which is switched on or off under the control of the electronic switch off device 10 as described below). However, other types of load can naturally be envisaged.

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In contrast, as represented diagrammatically by dashed lines in Figure 1, the load 4 need not always be present: the load 4 may be absent in certain situations (e.g. when the load 4 is a lamp, during a replacement of the load 4 by the user, or, when the switch-off device 10 is incorporated in a socket outlet, when no electrical appliance is plugged into the socket outlet. Once the electronic switch-off device 10 is connected to the voltage source 2 as shown in Figure 1, the electronic switch-off device 10 must thus be able to operate both in the presence of the load 4 and also in the absence of the load 4. The electronic switch-off device 10 includes a first inlet terminal 12, a second inlet terminal 14, a first outlet terminal 16, and a second outlet terminal 18. In the presently described embodiment, the first inlet terminal 12 is for connecting to the line terminal L of the voltage source 2, while the second inlet terminal 14 is for connecting to the neutral terminal N of the voltage source 2. As can be seen in Figure 1, the electronic switch-off device 10 includes a measurement circuit 30 and a controllable switch 22 that are connected in series between the first inlet terminal 12 and the first outlet terminal 16. In this embodiment, the second inlet terminal 14 and the second outlet terminal 18 are electrically connected to each other directly. In other words, the second inlet terminal 14 and the second outlet terminal 18 are identical in electrical potential. The measurement circuit 30 is designed to produce a measurement M of a magnitude of the electricity consumed through the controllable switch 22. In this embodiment, the electrical magnitude is the electric current passing through the controllable switch 22; in a variant, it could be the power consumed through the controllable switch 22. By way of

20499183_1 (GHMatters) P114597.AU example, the measurement circuit 30 is formed by means of a shunt.

The electronic switch-off device 10 also includes a

control circuit 20 that receives the measurement M produced by

the measurement circuit 30.

The control circuit 20 may also control the opening or

the closing of the controllable switch 22 by means of a

control signal S.

By way of example, the control circuit 20 is a

microcontroller. Such a microcontroller typically comprises a

processor and at least one memory. In particular, the memory

stores computer-program instructions designed so that when the

instructions are executed by the processor the microcontroller

implements the functions and the methods described below (in

particular the method described below with reference to

Figure 2).

In a variant, the control circuit 20 could be an

application specific programmed circuit.

As shown diagrammatically in Figure 1, and by way of

example, the control circuit 20 is powered by a power-supply

circuit 32 that is connected firstly to the first inlet

terminal 12, and secondly to the second inlet terminal 14, the

power-supply circuit 32 thus receiving the voltage generated

by the voltage source 2 (i.e. the mains voltage in this

embodiment).

Although not shown in Figure 1, in practice, the power

supply circuit 32 may optionally supply power to other

elements of the electronic switch-off device 10.

In a first embodiment, the control circuit 20 receives

control information C (or local control information C) coming

from a human-machine interface 26 that is provided on the

electronic switch-off device 10. By way of example, the

human-machine interface 26 is a button, such as a pushbutton.

20499183_1 (GHMatters) P114597.AU

In this configuration, the control circuit 20 generates a control signal S (for opening or closing the control switch 22) in particular as a function of the control information C produced by the human-machine interface 26. By way of example, provision can be made for the control signal S to toggle between a state that causes the controllable switch 22 to close and a state that causes the controllable switch 22 to open each time the human-machine interface 26 is actuated, (i.e. each time the pushbutton 26 is pressed). In a second embodiment (as represented by dashed lines in Figure 1), and optionally combinable with the first embodiment, the control circuit 20 receives control information C' (or remote control information C') coming from an external control appliance 6 and via a communications circuit 28 that is in communication with the control appliance 6. In practice, the communications circuit 28 (that in this configuration is provided on the electronic switch-off device 10 as shown by dashed lines in Figure 1) may be suitable for establishing a wireless connection with the control appliance 6, and thus for exchanging data (in particular control information C') with the control appliance 6. In a variant, the communications circuit 28 could be suitable for establishing a wired connection with the control appliance 6, optionally a wired connection using the cables of the above-mentioned electricity network (e.g. by means of power line communication technology). It should be observed that, in practice, the control information C' could be transmitted from the control appliance 6 (e.g. in this configuration a user terminal such as a smartphone) to the communications circuit 28 through various networks (e.g. including a cell-phone network or a wired or wireless local network).

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In addition, the communications circuit 28 is connected to the control circuit 20 (e.g. by means of a data bus) so as to transmit, to the control circuit 20, the data (in particular control information C') received by the communications circuit 28 (in particular coming from the control appliance 6). The electronic switch-off device 10 also includes a finite-impedance circuit 24 that is connected between the first outlet terminal 16 and the second outlet terminal 18. By way of example, the finite-impedance circuit 24 is a two pole electric circuit (in this embodiment a resistor), having one terminal connected to the first outlet terminal 16 and the other terminal connected to the second outlet terminal 18 in this embodiment. By way of example, the finite-impedance circuit 24 has a resistance lying in the range 100 kilohms (kQ) to 1 megohm (MQ), in this embodiment a resistance of 470 kQ. When the control circuit 20 commands the controllable switch 22 to open (by generating an opening control signal S), generally on receiving corresponding control information C, C', the control circuit 20 monitors the measurement M of the magnitude of the electricity consumed through the controllable switch 22 (measurement M received from the measurement circuit 30, as mentioned above). In normal operation, the controllable switch 22 is indeed opened by the opening control signal S, and consequently no current can flow between the first inlet terminal 12 and the first outlet terminal 16. The measurement M produced by the measurement circuit 30 (and transmitted to the control circuit 20) then indicates zero consumption (i.e. zero current through the controllable switch 22). In contrast, if the measurement circuit 30 produces a measurement M that is indicative of non-zero consumption (in

20499183_1 (GHMatters) P114597.AU this circumstance a non-zero current through the controllable switch 22), this means that current is flowing through the controllable switch 22 despite the opening control signal S, and this indicates that the controllable switch 22 is held in its closed position (in other words it is "stuck").

It should be observed that, as a result of the presence

of the finite-impedance circuit 24 that is connected between

the first outlet terminal 16 and the second outlet terminal

18, the current is present even in the absence of the load 4.

Thus, if the control circuit 20 generates an opening

control signal S for opening the controllable switch 22 and

receives a measurement M that is indicative of non-zero

consumption, the control circuit 20 generates a fault

indication I, I', e.g. issuing a lighting I for switching on a

fault indicator lamp 34 (in practice typically a light

emitting diode that can be seen by the user) and/or

transmitting fault information I' to the communications

circuit 28. The fault information I' can then be transmitted

by the communications circuit 28 to a user terminal (e.g. a

smartphone) of the user.

To do this, an electronic identifier (e.g. an email

address or a telephone number) associated with the user is

stored in the control circuit 20 or the communications circuit

28, for example; on receiving the fault information I' coming

from the control circuit 20, the communications circuit 28

transmits the fault information I' using the stored electronic

identifier.

In an embodiment that can be envisaged, the control

circuit 20 may also monitor the measurement M of the magnitude

of the electricity consumed through the controllable switch 22

when the control circuit 20 generates a closing control signal

S for closing the controllable switch 22.

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In this circumstance, in normal operation, the

electricity consumption is not zero as a result of current

flowing through the controllable switch 22 (for powering the

finite-impedance circuit 24 and possibly the load 4).

As a result, if the control circuit 20 receives a

measurement M that is indicative of a zero consumption through

the controllable switch 22 while the control circuit 20

generates a closing control signal S for closing the

controllable switch, this also indicates an operating fault

and the control circuit 20 can then cause a fault indication

to be lit (possibly different from the fault indicator lamp

34) and/or cause fault information be sent to a user terminal

via the communications circuit 28.

Figure 2 shows an example of a method that can be

implemented by the control circuit 20 within the electronic

switch-off device 10.

The method begins at step E2 during which the control

circuit 20 transmits a closure control signal S to the

controllable switch. The controllable switch 22 is thus

normally closed and, if a load 4 is present, said load is

powered through the controllable switch 22.

At step E4, the control circuit 20 receives a control

information C, C' (e.g. as a result of the user pressing on

the pushbutton 26).

As a consequence of receiving the control information C,

C', the control circuit 20 causes the control signal S to

toggle and thus transmit an opening control signal S at step

E6 to the controllable switch 22.

While the opening control signal S is applied to the

controllable switch 22, the control circuit 20, at step E8,

acquires the measurement M of the magnitude of the electricity

consumed through the controllable switch 22, i.e. the current

20499183_1 (GHMatters) P114597.AU measurement provided by the measurement circuit 30 connected in series with the controllable switch 22.

If the received measurement M indicates electricity

consumption that is zero (current that is zero), this

indicates that the controllable switch 22 is indeed open and

that the electronic switch-off device 10 is functioning

normally. The method may optionally loop to step E8 in order

to acquire a new measurement M coming from the measurement

circuit 30 and continue to monitor the measurement M.

If the received measurement M indicates electricity

consumption that is not zero, this indicates that the

controllable switch 22 has remained in its closed position

despite the opening control signal S being applied to the

controllable switch 22, and in this circumstance the method

continues to step E10 in order to signal the fault to the

user.

At step E10, the control circuit 20 generates a fault

indication for the user, e.g. by issuing the lighting control

signal I for switching on the fault indicator lamp 34 and/or

by transmitting fault information I' to an external electronic

appliance (such as a smartphone of the user) by means of the

communications circuit 28.

It is to be understood that, if any prior art publication

is referred to herein, such reference does not constitute an

admission that the publication forms a part of the common

general knowledge in the art, in Australia or any other

country.

In the claims which follow and in the preceding

description of the invention, except where the context

requires otherwise due to express language or necessary

implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense,

i.e. to specify the presence of the stated features but not to

20499183_1 (GHMatters) P114597.AU preclude the presence or addition of further features in various embodiments of the invention.

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Claims

1. An electrical accessory of the switch type comprising a

first inlet terminal, a second inlet terminal, a first outlet

terminal, a second outlet terminal, a controllable switch that

is interposed between the first inlet terminal and the first

outlet terminal, and a control circuit that is adapted to

produce a control signal for the controllable switch;

wherein said electrical accessory of the switch type

further comprises:

• a measurement circuit for measuring a magnitude of the

electricity consumed through the controllable switch; and

- a finite-impedance circuit that is interposed between

the first outlet terminal and the second outlet terminal; and

- in that the control circuit is designed to produce an

opening control signal for opening the controllable switch, to

monitor the measured electrical magnitude when the opening

control signal is produced, and to generate a fault indication

if the measured electrical magnitude indicates non-zero

electricity consumption through the controllable switch when

the opening control signal is produced.

2. An electrical accessory of the switch type according to

claim 1, wherein the fault indication is a lighting control

signal for switching on an indicator lamp.

3. An electrical accessory of the switch type according to

claim 1, wherein the fault indication is fault information

transmitted to a user terminal.

4. An electrical accessory of the switch type according to any

one of claims 1 to 3, including a human-machine interface that

20499183_1 (GHMatters) P114597.AU is designed to transmit local control information to the control circuit.

5. An electrical accessory of the switch type according to any one of claims 1 to 4, including a communications circuit that is designed to transmit remote control information to the control circuit.

6. An electrical accessory of the switch type according to any one of claims 1 to 5, wherein the measurement circuit is designed to measure electric current passing through the controllable switch, said electrical magnitude being said current.

7. An electrical accessory of the switch type according to any one of claims 1 to 6, wherein the finite-impedance circuit is a resistor that is connected between the first outlet terminal and the second outlet terminal.

8. A method of detecting a fault in an electrical accessory of the switch type comprising a first inlet terminal, a second inlet terminal, a first outlet terminal, a second outlet terminal, a controllable switch that is interposed between the first inlet terminal and the first outlet terminal, and a control circuit that is adapted to produce a control signal for the controllable switch, wherein the electrical accessory of the switch type includes a finite-impedance circuit that is interposed between the first outlet terminal and the second outlet terminal, and in that the method comprises the following steps: • measuring a magnitude of the electricity consumed through the controllable switch;

20499183_1 (GHMatters) P114597.AU

- the control circuit producing an opening control signal for opening the controllable switch; - monitoring the measured electrical magnitude when the opening control circuit is produced; and generating a fault indication if the measured electrical magnitude indicates non-zero electricity consumption through the controllable switch when the opening control signal is produced.

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