EP3839346A1

EP3839346A1 - Thermoelectric assembly for powering a plurality of electromagnetic valves of a cooking appliance

Info

Publication number: EP3839346A1
Application number: EP19383143.5A
Authority: EP
Inventors: Mikel Arizmendi Zurutuza; Marcos Pablo Curto
Original assignee: Orkli SCL
Current assignee: Orkli SCL
Priority date: 2019-12-19
Filing date: 2019-12-19
Publication date: 2021-06-23

Abstract

A thermoelectric assembly comprising a main current circuit (1) and at least one additional current circuit (1'), each associated with a respective electromagnetic valve (6, 6'), each current circuit (1, 1') comprising a thermocouple (2, 2"), a cable (3, 3') configured for connecting the thermocouple (2, 2') with the corresponding electromagnetic valve (6, 6'), and a transistor (9, 9') connected to the cable (3, 3') and configured for de-energizing the electromagnetic valve (6, 6') when said transistor (9, 9') is not powered. Each current circuit (1, 1') comprises a connection module (20, 20') housing the respective transistor (9, 9'). The main current circuit (1) further comprises a power supply (10), the connection modules (20, 20') being configured for being connected to one another such that the power supply (10) does not only power the transistor (9) of the main current circuit (1), but also the transistor (9') of the respective additional current circuit (1').

Description

TECHNICAL FIELD

The present invention relates to a thermoelectric assembly for powering a plurality of electromagnetic valves of a cooking appliance, each electromagnetic valve allowing or preventing the passage of gas to a respective burner of the cooking appliance.

PRIOR ART

Cooking appliances with burners, each of which having associated therewith a thermocouple connected to a respective electromagnetic valve are known in the state of the art, such that, when the thermocouple detects the presence of flame in the burner, it generates a thermoelectric current which is capable of keeping the electromagnetic valve energized at a given time, allowing the passage of gas to the corresponding burner.
EP 0288390 A1 furthermore describes electric circuits in which a MOSFET is arranged between the thermocouple and the electromagnetic valve, said MOSFET acting like a switch, such that depending on pre-established parameters, the MOSFET can open the circuit preventing the passage of current to the electromagnetic valve, and therefore causing the electromagnetic valve to close the passage of gas to the burner regardless of the presence of flame in the corresponding burner.
Moreover, powering thermoelectric circuits of this type with power supplies including transformers for galvanically isolating said thermoelectric circuits is also known, as described in US 2019/0195507 A1 .

DISCLOSURE OF THE INVENTION

The object of the invention is to provide a thermoelectric assembly for powering a plurality of electromagnetic valves of a cooking appliance, each electromagnetic valve being configured for closing the passage of gas to a corresponding burner of the cooking appliance, as defined in the claims.
The thermoelectric assembly according to the invention comprises a main current circuit associated with a respective electromagnetic valve, the main current circuit comprising a thermocouple configured for detecting flame in the corresponding burner, a cable connected to the thermocouple and configured for electrically connecting said thermocouple with the corresponding electromagnetic valve, and a transistor connected to the cable and configured for de-energizing the electromagnetic valve, and at least one additional current circuit associated with a respective electromagnetic valve, the additional current circuit comprising a thermocouple configured for detecting flame in the corresponding burner, a cable connected to the thermocouple and configured for electrically connecting said thermocouple with the corresponding electromagnetic valve, and a transistor connected to the cable and configured for de-energizing the electromagnetic valve to which it is connected.
The main current circuit comprises a connection module housing the transistor and a power supply, and the additional current circuit comprises a connection module comprising the corresponding transistor, the connection module of the main current circuit and the connection module of the additional current circuit being configured for being connected such that the power supply does not only power the transistor of the main current circuit, but also the transistor of the respective additional current circuit.
A thermoelectric assembly which, in addition to integrating the power supply in one of the current circuits, enables simple and quick connection between the different current circuits through the connection modules is thereby obtained, with the connection modules of the additional current circuits being powered through the power supply housed in the connection module of the main current circuit.
These and other advantages and features of the invention will become evident in view of the drawings and detailed description of the invention.

DESCRIPTION OF THE DRAWINGS

Figure 1 shows a wiring diagram of a thermoelectric assembly according to the invention comprising a main current circuit and additional current circuits.
Figure 2 shows a perspective view of the thermoelectric assembly schematically shown in Figure 1.
Figure 3 shows a detailed view of the wiring diagram of a connection module of the main current circuit shown in Figure 1.
Figure 4 shows a detailed view of a connection module of the additional current circuit shown in Figure 1.

DETAILED DISCLOSURE OF THE INVENTION

Figure 1 shows a thermoelectric assembly 100 according to the invention suitable for powering a plurality of electromagnetic valves 6 and 6' of a cooking appliance (not depicted in the drawings), each electromagnetic valve 6 and 6' being configured for closing the passage of gas to a corresponding burner (not depicted in the drawings) of the cooking appliance.
The thermoelectric assembly 100 comprises a main current circuit 1 and at least one additional current circuit 1', each of them associated with a respective electromagnetic valve 6 and 6', said additional current circuit being able to be connected to the main current circuit 1.
The main current circuit 1 comprises a thermocouple 2 configured for detecting flame in the corresponding burner, cables 3 and 4 connected to the thermocouple 3 and configured for electrically connecting said thermocouple 2 with the corresponding electromagnetic valve 6, a transistor 9 connected to one of the cables 3 and configured for de-energizing the electromagnetic valve 6, and a connection module 20 comprising a power supply 10 connected to the transistor 9.
In the embodiment shown in the drawings, the thermoelectric assembly 100 comprises two additional current circuits 1', each of them associated with a respective electromagnetic valve 6'. Regardless of whether the thermoelectric assembly 100 includes one, two, or a plurality of additional current circuits, the features of each additional current circuit are similar and will be described below.
Each additional current circuit 1', shown in detail in Figures 2 and 4, comprises a thermocouple 2' configured for detecting flame in the corresponding burner, cables 3', and 4' connected to the corresponding thermocouple 2' and configured for electrically connecting said thermocouple 2' with the corresponding electromagnetic valve 6', and a transistor 9' connected to the corresponding cable 3' and configured for de-energizing the electromagnetic valve 6' to which it is connected.
The features of the thermocouple 2' of each additional current circuit 1' are similar to those of the thermocouple 2. Similarly, the features of the cables 3', and 4' for connecting the thermocouple 2' to the electromagnetic valve 6' in the additional current circuit 1' are similar to those of the cables 3 and 4 of the main current circuit, so what is described above in relation to these elements for the main current circuit is applicable to the additional current circuits.
The main current circuit 1 comprises a connection module 20 housing the transistor 9 and a power supply 10, whereas each additional current circuit 1' comprises a connection module 20' in turn comprising the corresponding transistor 9', the connection module 20 of the main current circuit 1 and the connection module 20' of the additional current circuit 1' being configured for being connected such that the power supply 10 does not only power the transistor 9 of the main current circuit 1, but also the transistor 9' of the respective additional current circuit 1'.
Each transistor 9' of the respective additional current circuit 1' has the same features and operates in the same manner as the transistor 9 of the main current circuit 1. The transistors 9 and 9' are field-effect transistors, preferably MOSFET type transistors. Each transistor 9 and 9' comprises a port terminal 9a and 9a', a drain terminal 9b and 9b', and a source terminal 9c and 9c', each transistor 9 and 9' being connected to the power supply 10 through the respective port terminal 9a and 9a' and source terminal 9c and 9c'. Each transistor 9 and 9' behaves like a switch. In particular, when it operates in the cut-off region, conduction between the source terminal 9c and 9c' and the respective drain terminal 9b and 9b' does not occur, so it operates like an open switch regardless of whether or not the respective thermocouple 2 and 2' detects the presence of flame, and therefore the respective electromagnetic valve 6 and 6' is kept de-energized, preventing the passage of gas to the burner corresponding. When the power supply 10 is connected to an external energy source 8, it powers the transistor 9 which operates like a closed switch, the electromagnetic valve 6 is kept energized as long as the thermocouple 2 detects flame in the burner and a thermoelectric current capable of keeping the electromagnetic valve energized is generated.
The power supply 10 comprises two input terminals 22 and 23 configured for being connected to the external energy source 8, forming a form-fitting connection, and the connection module 20' of each additional current circuit 1' comprises an input terminal 22' configured for being connected with an output terminal 24 of the connection module 20 of the main current circuit 1, forming a form-fitting connection.
These form-fitting connections are simple and quick assembly/disassembly connections. In a preferred embodiment, the output terminal 24 of the connection module 20 of the main current circuit 1 and the input terminal 22' of the connection module 20' of the first additional current circuit 1' are configured for being connected, providing a male-female attachment.
Moreover, the additional current circuits 1' are connected to one another through respective connection modules 20' and powered through the power supply 10 housed in the connection module 20 of the main current circuit 1. In particular, in the embodiment shown in the drawings, the input terminal 22' of the connection module 20' of one of the additional current circuits 1' is connected to the output terminal 24' of the connection module 20' of another additional current circuit 1', providing a form-fitting connection. This form-fitting connection is a simple and quick assembly/disassembly connection. In a preferred embodiment, the input terminal 22' of the connection module 20' of one of the additional current circuits 1' and the output terminal 24' of the connection module 20' of the another additional current circuit 1' are configured for being connected, providing a male-female attachment.
The connection module 20 of the main current circuit 1, shown in Figure 2, comprises a body 21 inside which there is housed the power supply 10 and the transistor 9, with the input terminals 22 and 23 projecting from the body 21. The body 21 is made of an insulating material and comprises a corresponding cover 26 which closes the corresponding housing.
In the embodiment shown in the drawings, the power supply 10 and the transistor 9 are assembled on a PCB housed inside the body 21.
The input terminals 22 and 23 of the power supply 10 and the output terminal 24 project towards the outside of the body 21. In the embodiment shown in Figure 2, the input terminals 22 and 23 are arranged substantially parallel to one another and to the output terminal 24.
The connection module 20 of the main current circuit 1 may comprise an additional output terminal (not depicted) configured for connecting with a presence sensor for detecting the presence of utensils associated with the corresponding burner. Said additional output terminal will provide a form-fitting connection with the corresponding presence sensor.
The connection module 20' of each additional current circuit 1' comprises a body 21' inside which there is housed the respective transistor 9', with the input terminal 22' and the respective output terminal 24' projecting towards the outside of the respective body 21'. In the embodiment shown in the drawings, the input terminal 22' of the connection module 20' of the respective additional current circuit 1' is substantially parallel to the corresponding output terminal 24'. Each body 21' is made of an insulating material. Each body 21' comprises a cover 26' which closes the corresponding housing.
The connection module 20' of each additional current circuit 1' may comprise an additional output terminal configured for connecting with a presence sensor for detecting the presence of utensils associated with the corresponding burner. Said additional output terminal will provide a form-fitting connection with the corresponding presence sensor.
Moreover, the power supply 10 comprises a rectifier 11 configured for transforming the alternating current of the external energy source 8 into direct current and a resistive block 14 connected between one of the input terminals 22 and 23 and the rectifier 11, the resistive block 14 being configured for minimizing the current circulating through the power supply 10 to a value equivalent to the galvanic isolation. The resistance of the resistive block 14 is about 2.24 mohms. A simple power supply that does not require a transformer and provides the required galvanic isolation level is thereby obtained. The power supply is optimized and minimized, where it can be incorporated in the connection module 20 of the main current circuit 1.
In the embodiment shown in Figure 1, the power supply 10 comprises two resistive blocks 14, each of them connected to the corresponding input terminal 22 and 23. Preferably, each resistive block 14 comprises at least two resistors 14a and 14b arranged such that they are connected in series. The resistance resulting from the two resistive blocks 14 is about 2.24 mohms.
The power supply 10 further comprises capacitance filters 12 connected in parallel to one another and in parallel to the rectifier 11, the capacitance filters 12 being configured for filtering or smoothing out ripple, resulting in a direct current whose voltage would virtually not vary over time. The power supply 10 further comprises a diode 13 connected in parallel to the rectifier 11 and to the capacitance filters 12. In a preferred embodiment, the rectifier 11 is a diode bridge.
Moreover, both the main current circuit 1 and each additional current circuit 1' further comprise a discharge resistor 15 and 15' of the respective transistor 9 and 9', said discharge resistor 15 and 15' being connected in parallel to the respective transistor 9 and 9' and configured for assuring the opening of the respective transistor 9 and 9' when said transistor 9 and 9' is no longer powered by the power supply 10. The discharge resistor 15 and 15' is arranged such that it is housed in the body 21 and 21' of the respective connection module 20 and 20'. In particular, the discharge resistor 15 of the main current circuit 1 is assembled on the PCB together with the transistor 9 and the power supply 10.
Both the main current circuit 1 and each additional current circuit 1' also comprise a safety resistor 16 and 16' connected in series with the port 9a and 9a' of the transistor 9 and 9' and configured for limiting the current that would go to the respective current circuit 1 and 1' from the power supply 10 in the event of a short-circuit failure of the respective transistor 9 and 9'. The discharge resistor 16 and 16' is arranged such that it is housed in the body 21 of the respective connection module 20 and 20'. In particular, the discharge resistor 16 of the main current circuit 1 is assembled on the PCB together with the transistor 9 and the power supply 10.
Moreover, an electromechanical switch 25 is arranged between the power supply 10 and the power supply external 8.
In other embodiments not shown in the drawings, the switch 25 can be connected between the power supply 10 and the transistor 9. In that case, the connection module 20 houses the switch 25 in the body 21. In one embodiment, the switch 25 is assembled on the PCB housed inside the body 21.
In both cases, when the switch 25 is closed, and the power supply 10 connected to the external energy source 8, the power supply 10 powers the transistor 9 such that the transistor 9 allows current to pass therethrough. With the switch 25 closed, if the thermocouple 2 detects the presence of flame, it will generate a thermoelectric current that goes through the transistor 9 keeping the electromagnetic valve 6 such that it allows the passage of gas to the burner. When the thermocouple 2 does not detect any flame, and therefore no longer generate the thermoelectric current required for keeping the electromagnetic valve 6 energized, said electromagnetic valve 6 closes the passage of gas. When the corresponding signal is sent to the switch 25 from a non-depicted control so as to open said switch 25, the transistor 9 is not powered, so it acts like an open switch, not allowing current to go from the thermocouple 2 to the electromagnetic valve 6, the passage of gas is thereby closed. The transistor 9 therefore allows acting on the electromagnetic valve 6 de-energizing it when a previously defined parameter is achieved, said parameter not being the presence of flame in the burner 2.
Each additional current circuit 1' further comprises a diode 13' connected between the discharge resistor 15' and the safety resistor 16', and in parallel to the transistor 9'.
In the embodiment shown in the drawings, the output terminal 24' of the connection module 20' of the corresponding additional current circuit 1' is connected between the discharge resistor 15' of the additional current circuit 1' and the safety resistor 16 of the respective additional current circuit 1'.
In other embodiments that are not shown, the thermoelectric assembly may comprise a single additional current circuit or a plurality of additional current circuits that can be connected to one another through respective connection modules, the single additional current circuit or a circuit of the plurality of additional current circuits being arranged such that it is connected to the main current circuit. A thermoelectric assembly in which the circuits associated with the thermocouples can be quickly coupled to one another is thereby obtained, with the power supply being integrated in one of said circuits. A modular solution that can be scaled according to needs and readily connected to/disconnected from one another is thereby provided. The features of the single additional current circuit or of each of the additional current circuits of the plurality of additional current circuits are those described for the two additional current circuits of the embodiment shown in the drawings.
The thermoelectric assembly 100 operates in the following manner, when the switch 25 is closed and the main current circuit 1 connected to the external energy source 8, the power supply 10 powers the transistor 9 of the main current circuit 1 and the transistors 9' of the respective additional current circuits 1', said transistors 9 and 9' acting like closed switches, allowing the thermoelectric current which is generated in the respective thermocouple 2 and 2' when there is flame in the corresponding burner to energize the respective electromagnetic valve 6 and 6'. When a parameter whereby it is considered necessary to close the passage of gas to one of the burners in particular is detected, the switch 25 opens such that the transistor 9 of the main current circuit 1 and the transistors 9' of the additional current circuits 1' are nor powered and act like open switches, the corresponding electromagnetic valves 6 and 6' being de-energized.

Claims

Thermoelectric assembly for powering a plurality of electromagnetic valves (6, 6') of a cooking appliance, each electromagnetic valve (6, 6') being configured for closing the passage of gas to a corresponding burner of the cooking appliance, the thermoelectric assembly (30) comprising a main current circuit (1) associated with a respective electromagnetic valve (6), the main current circuit (1) comprising a thermocouple (2) configured for detecting flame in the corresponding burner, a cable (3) connected to the thermocouple (2) and configured for electrically connecting said thermocouple (2) with the corresponding electromagnetic valve (6), and a transistor (9) connected to the cable (3) and configured for de-energizing the electromagnetic valve (6) when said transistor (9) is no longer powered, and at least one additional current circuit (1') associated with a respective electromagnetic valve (6'), the additional current circuit (1') comprising a thermocouple (2') configured for detecting flame in the corresponding burner, a cable (3') connected to the thermocouple (2') and configured for electrically connecting said thermocouple (2') with the corresponding electromagnetic valve (6'), and a transistor (9') connected to the cable (3') and configured for de-energizing the electromagnetic valve (6') to which it is connected, characterized in that the main current circuit (1) comprises a connection module (20) housing the transistor (9) and a power supply (10), and the additional current circuit (1') comprises a connection module (20') comprising the corresponding transistor (9'), the connection module (20) of the main current circuit (1) and the connection module (20') of the additional current circuit (1') being configured for being connected such that the power supply (10) does not only power the transistor (9) of the main current circuit (1), but also the transistor (9') of the respective additional current circuit (1') when said power supply (10) is connected to an external energy source (8).
Thermoelectric assembly according to the preceding claim, wherein the power supply (10) comprises two input terminals (22, 23), the input terminals (22, 23) being configured for being connected to the external energy source (8) forming a form-fitting connection, and the connection module (20') of the additional current circuit (1') comprises an input terminal (22') configured for being connected with an output terminal (24) of the connection module (20) of the main current circuit (1) forming a form-fitting connection.
Thermoelectric assembly according to the preceding claim, wherein the connection module (20) of the main current circuit (1) comprises a body (21) inside which there is housed the power supply (10) and the transistor (9), with the input terminals (22, 23) and the output terminal (24) projecting towards the outside of the body (21).
Thermoelectric assembly according to the preceding claim, wherein the power supply (10) and the transistor (9) of the main current circuit (1) are assembled on a PCB housed in the body (21).
Thermoelectric assembly according to any of claims 2 to 4, comprising a plurality of additional thermoelectric current circuits (1') each of them associated with a respective electromagnetic valve (6'), each additional current circuit (1') being configured for being connected with another additional current circuit (1') through respective connection modules (20') of each additional current circuit (1'), each connection module (20') of the additional current circuit (1') comprising an output terminal (24'), such that the input terminal (22') of the connection module (20') of one of the additional thermoelectric current circuits (1') and the output terminal (24') of the connection module (20') of another additional current circuit (1') are configured for being connected, providing a form-fitting connection.
Thermoelectric assembly according to the preceding claim, wherein each connection module (20') of the additional current circuit (1') comprises a body (21') inside which there is housed the corresponding transistor (9'), with the input terminal (22') and the respective output terminal (24') projecting towards the outside of the body (21').
Thermoelectric assembly according to claim 5 or 6, wherein the connection module (20') of the corresponding additional current circuit (1') comprises an additional output terminal configured for being connected with a presence sensor for detecting the presence of utensils associated with the corresponding burner.
Thermoelectric assembly according to any of claims 2 to 7, wherein the connection module (20) of the main current circuit (1) comprises an additional output terminal configured for connecting with a presence sensor for detecting the presence of utensils associated with the corresponding burner.
Thermoelectric assembly according to any of claims 2 to 8, wherein the power supply (10) comprises a rectifier (11) configured for transforming the alternating current of the energy source (8) into direct current, and a resistive block (14) connected between at least one input terminal (22, 23) of the power supply (10) and the rectifier (11) and configured for minimizing the current circulating through the power supply (10) to a value equivalent to the galvanic isolation.
Thermoelectric assembly according to the preceding claim, wherein the power supply (10) comprises two resistive blocks (14), each of them connected to the corresponding input terminal (22, 23) of the power supply (10).
Thermoelectric assembly according to claim 9 or 10, wherein the resistive block (14) comprises at least two resistors (14a, 14b) arranged such that they are connected in series.
Thermoelectric assembly according to any of the preceding claims, wherein the main current circuit (1) and each additional current circuit (1'), respectively, comprise a discharge resistor (15, 15') of the transistor (9, 9') connected in parallel to the respective transistor (9, 9') and configured for assuring the opening of the transistor (9, 9') when the voltage supplied to the port (9c, 9c') of the transistor (9, 9') is eliminated.
Thermoelectric assembly according to any of the preceding claims, wherein the main current circuit (1) and each additional current circuit (1'), respectively, comprise a safety resistor (16, 16') connected in series with the port (9c, 9c') of the transistor (9, 9') and configured for limiting the current that would go to the corresponding current circuit (1, 1') from the power supply (10) in the event of a short-circuit failure of the transistor (9, 9').