Patent Publication Number: US-2021193358-A1

Title: Thermoelectric assembly for powering electromagnetic valves of a cooking appliance

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application relates to and claims the benefit and priority to each of European Patent Appl. Nos. EP19383142.5 and EP19383143.7, each filed on Dec. 19, 2019. 
     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. 
     BACKGROUND 
     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. 
     European Publication No. EP 0288390 A1 furthermore describes electric circuits in which a MOSFET is arranged between the thermocouple and the electromagnetic valve, the 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 the thermoelectric circuits is also known, as described in U.S. Publication No. 2019/0195507 A1. 
     SUMMARY 
     Disclosed is 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. 
     The thermoelectric assembly comprises a main current circuit associated with a respective electromagnetic valve, the main current circuit including a thermocouple configured for detecting flame in the corresponding burner, a cable connected to the thermocouple and configured for electrically connecting the thermocouple with the corresponding electromagnetic valve, and a transistor connected to the cable and configured for de-energizing the electromagnetic valve. 
     The main current circuit includes a connection module comprising a power supply connected to the transistor, input terminals configured for being connected to an external energy source, a rectifier configured for transforming the alternating current of the external energy source into direct current, and a resistive block connected between one of the input terminals and the rectifier and configured for minimizing the current circulating through the power supply to a value equivalent to the galvanic isolation. 
     A thermoelectric assembly having a main current circuit with a basic and simple power supply is thereby obtained, without having to include a transformer in the power supply for obtaining the required galvanic isolation. The power supply will thus be simpler and more cost-effective, and is therefore integrated in the main current circuit, particularly in the connection module together with the transistor. A main current circuit that is compact, simple, and can be readily connected to the external energy source is thereby obtained. 
     These and other advantages and features will become evident in view of the drawings and detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a wiring diagram of a thermoelectric assembly according to one embodiment comprising a main current circuit and additional current circuits. 
         FIG. 2  shows a perspective view of the thermoelectric assembly schematically shown in  FIG. 1 . 
         FIG. 3  shows a detailed view of the wiring diagram of a connection module of the main current circuit shown in  FIG. 1 . 
         FIG. 4  shows a detailed view of a connection module of the additional current circuit shown in  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows a thermoelectric assembly  100  according to one embodiment 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  associated with a respective electromagnetic valve  6 . The main current circuit  1  comprises a thermocouple  2  configured for detecting flame in the corresponding burner with cables  3  and  4  connected to the thermocouple  2  and configured for electrically connecting the thermocouple  2  with the corresponding electromagnetic valve  6  through a connector  5 , The main current circuit  1  also includes a transistor  9  connected to one of the cables  3  and configured for de-energizing the electromagnetic valve  6 . A connection module  20  comprising a power supply  10  is connected to the transistor  9 . 
     The transistor  9  is a field-effect transistor, preferably a MOSFET type transistor. The transistor  9  comprises a port terminal  9   a , a drain terminal  9   b , and a source terminal  9   c , the transistor  9  being connected to the power supply  10  through the port terminal  9   a  and source terminal  9   c . The transistor  9  behaves like a switch. In particular, when it operates in the cut-off region conduction between the source terminal  9   c  and the drain terminal  9   b  does not occur, so it operates like an open switch regardless of whether or not the thermocouple  2  detects the presence of flame, and therefore the electromagnetic valve is kept de-energized, preventing the passage of gas to the corresponding burner. When the power supply  10  is connected to the external energy source  8 , it powers the transistor  9  which operates like a closed switch, the electromagnetic valve 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 transistor  9  has two connection terminals  27  and  28 , each of which is connected to the cable  3  of the thermocouple  2 . 
     The power supply  10  comprises two input terminals  22  and  23  configured for being connected to the external energy source  8 , 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 milliohms. 
     In the embodiment shown in the drawings, 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  14   a  and  14   b  arranged such that they are connected in series. The resistance resulting from the two resistive blocks  14  is about 2.24 milliohms. 
     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, the first input terminal  22  and the second input terminal  23  of the power supply  10  are configured for being connected with the external energy source  8 , providing a form-fitting connection with the external energy source  8 . This form-fitting connection is a simple and quick assembly/disassembly connection. In a preferred embodiment, the first input terminal  22  and the second input terminal  23  of the main 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  FIG. 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 housing where the power supply  10  and the transistor  9  are arranged. 
     In the embodiment shown in the drawings, the power supply  10  and the transistor  9  are assembled on a PCB (not depicted) housed inside the body  21 . 
     The power supply  10  comprises an output terminal  24  projecting from the body  21 . The input terminals  22  and  23  and the output terminal  24  project towards the outside orthogonal to the cover  26 . 
     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. The additional output terminal will provide a form-fitting connection with the corresponding presence sensor. 
     The main current circuit  1  further comprises a discharge resistor  15  of the transistor, the discharge resistor  15  being connected in parallel to the transistor  9 , the discharge resistor  15  assuring the opening of the transistor  9  when the transistor  9  is no longer powered by the power supply  10 . The discharge resistor  15  is arranged such that it is housed in the body  21  of the connection module  20 . In particular, the discharge resistor  15  is assembled on the PCB together with the transistor  9  and the power supply  10 . 
     The main current circuit  1  also comprises a safety resistor  16  connected in series with the port  9   a  of the transistor  9 . The safety resistor  16  limits the current that would go to the main current circuit  1  from the power supply  10  in the event of a short-circuit failure of the transistor  9 . The discharge resistor  16  is arranged such that it is housed in the body  21  of the connection module  20 . In particular, the discharge resistor  16  is assembled on the PCB together with the transistor  9  and the power supply  10 . 
     Moreover, an electromechanical switch  27  is arranged between the power supply  10  and the external power supply  8 . 
     In other embodiments not shown in the drawings, the switch  27  can be connected between the power supply  10  and the transistor  9 . In that case, the connection module  20  houses the switch  27  in the body  21 . In one embodiment, the switch  27  is assembled on the PCB housed inside the body  21 . 
     In both cases, when the switch  27  is closed and the power supply  10  is 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  27  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, the electromagnetic valve  6  closes the passage of gas. When the corresponding signal is sent to the switch  27  from a non-depicted control so as to open the switch  27 , 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, the parameter not being the presence of flame in the burner  2 . 
     The thermoelectric assembly  100  further comprises at least one additional current circuit  1 ′ associated with a respective electromagnetic valve  6 ′, the additional current circuit  1 ′ being able to be connected to the main current circuit  1 . 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 ′ 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 the thermocouple  2 ′ with the corresponding electromagnetic valve  6 ′ through a connector  5 ′, and a transistor  9 ′ connected to the corresponding cable  3 ′ and configured for de-energizing the electromagnetic valve  6 ′ to which it is connected. 
     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 , so what has been described above is applicable to the transistors of the additional current circuits. The features of the thermocouple  2 ′ of each additional current circuit  1 ′ are similar to those of 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  1 , so what is described above in relation to these elements for the main current circuit is applicable to the additional current circuits. 
     Each additional current circuit  1 ′ comprises a connection module  20 ′ housing the corresponding transistor  9 ′, each connection module  20 ′ comprising an input terminal  22 ′ connected to the corresponding transistor  9 ′. In particular, the input terminal  22 ′ is connected to the port  9   a ′ of the respective transistor  9 ′. The connection module  20 ′ of each additional current circuit  1 ′, shown in  FIGS. 2 and 4 , comprises an output terminal  24 ′. Each input terminal  22 ′ of the corresponding additional current circuit  1 ′ is configured for being connected to the output terminal  24  of the connection module  20  of the main current circuit  1  or to the output terminal  24 ′ of another connection module  20 ′ of the additional current circuit  1 ′. 
     In the embodiment shown in the drawings, one of the additional current circuits  1 ′ (hereinafter, first additional current circuit  1 ′) is connected to the main current circuit  1  through respective connection modules  20  and  20 ′. In particular, the input terminal  22 ′ of the connection module  20 ′ of the first additional current circuit  1 ′ is connected to the output terminal  24  of the main current circuit  1  as shown in  FIG. 2 . Furthermore, both additional current circuits  1 ′ and  1 ″ are connected to one another through respective connection modules  20 ′. In particular, the input terminal  22 ′ of the connection module  20 ′ of another additional current circuit  1 ″ (hereinafter, second additional current circuit  1 ″) is connected to the output terminal  24 ′ of the connection module  20 ′ of the first additional current circuit  1 ′. 
     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 an additional current circuit  1 ′ are configured for being connected, providing a form-fitting connection. This form-fitting connection is a simple and quick assembly/disassembly connection. 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 output terminal  24 ′ of the connection module  20 ′ of the first additional current circuit  1 ′ and the input terminal  22 ′ of the connection module  20 ′ of the second additional current circuit  1 ′ are configured for being connected, providing a form-fitting connection. This form-fitting connection is a simple and quick assembly/disassembly connection. In a preferred embodiment, the output terminal  24 ′ of the connection module  20 ′ of the first additional current circuit  1  and the input terminal  22 ′ of the connection module  20 ′ of the second additional current circuit  1 ′ are configured for being connected, providing a male-female attachment. 
     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 ′. Each body  21 ′ is made of an insulating material. Each body  21 ′ comprises a corresponding cover  26 ′ which closes the corresponding housing. In the embodiment shown in the drawings, the input terminal  22 ′ and the output terminal  24 ′ of the connection module  20 ′ of the corresponding additional current circuit  1 ′ project towards the outside orthogonal to the cover  26 ′. 
     The connection module  20 ′ of each additional 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. The additional output terminal will provide a form-fitting connection with the corresponding presence sensor. 
     Each additional current circuit  1 ′ further comprises a discharge resistor  15 ′ of the transistor  9 ′, the discharge resistor  15 ′ being connected in parallel to the transistor  9 ′ and configured for assuring the opening of the transistor  9 ′ when the transistor  9 ′ is no longer powered by the power supply  10 . The discharge resistor  15 ′ is arranged such that it is housed in the body  21 ′ of the connection module  20 ′. In particular, the discharge resistor  15 ′ is assembled on the PCB together with the transistor  9 ′. 
     Each additional current circuit  1 ′ comprises a safety resistor  16  connected in series with the port  9   a ′ of the transistor  9 ′ and configured for limiting the current that would go to the additional current circuit  1 ′ from the power supply  10  in the event of a short-circuit failure of the corresponding transistor  9 ′. The discharge resistor  16 ′ is arranged such that it is housed in the body  21 ′ of the respective connection module  20 ′. In particular, the discharge resistor  16 ′ is assembled on the PCB together with the respective transistor  9 ′. 
     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 the circuits. A modular solution that can be scaled according to needs and readily detachable 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  27  is closed and the main current circuit  1  connected to the external energy source  8 , the power supply  10  powers the transistors  9  and  9 ′ of the main current circuit  1  and of the respective additional current circuits  1 ′, the 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  27  opens such that the transistors  9  and  9 ′ of the main current circuit  1  and of the additional current circuits  1 ′ are not powered and act like open switches, the corresponding electromagnetic valve  6  and  6 ′ being de-energized. 
     The following clauses disclose in an unlimited way additional embodiments. 
     Clause 1. A 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  100  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 the 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 , the main current circuit  1  comprises a connection module  20  comprising a power supply  10  connected to the transistor  9 , the power supply  10  comprising input terminals  22 ,  23  configured for being connected to an external energy source  8 , 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 ,  23  and the rectifier  11 , the resistive block  14  replacing a transformer and being configured for minimizing the current circulating through the power supply  10  to a value equivalent to the galvanic isolation that otherwise would have been provided by the transformer. 
     Clause 2. The thermoelectric assembly according to the preceding clause, wherein the resistive block  14  comprises at least two resistors  14   a ,  14   b  arranged such that they are connected in series. 
     Clause 3. The thermoelectric assembly according to any of the preceding clauses, wherein the power supply  10  comprises two resistive blocks  14 , each of them connected to the corresponding input terminal  22 ,  23 . 
     Clause 4. The thermoelectric assembly according to clause 1 or 2, wherein the resistance of the resistive block  14  is about 2.24 milliohms. 
     Clause 5. The thermoelectric assembly according to clause 3, wherein the resistance of the two resistive blocks  14  is about 2.24 milliohms. 
     Clause 6. The thermoelectric assembly according to any of the preceding clauses, wherein the first input terminal  22  and the second input terminal  23  are configured for being connected, providing a form-fitting connection with the external energy source  8 . 
     Clause 7. The thermoelectric assembly according to any of the preceding clauses, wherein the connection module  20  comprises a body  21  inside which there is housed the power supply  10  and the transistor  9 , with the input terminals  22 ,  23  and an output terminal  24  projecting from the body  21 . 
     Clause 8. The thermoelectric assembly according to clause 7, wherein the connection module  20  comprises an additional output terminal configured for connecting with a presence sensor for detecting the presence of utensils associated with the corresponding burner. 
     Clause 9. The thermoelectric assembly according to clause 7 or 8, comprising an additional current circuit  1 ′ associated with a respective electromagnetic valve  6 ′, the additional current circuit Clause 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 the 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, the additional current circuit  1 ′ comprising a connection module  20 ′ housing the corresponding transistor  9 ′, the connection module  20 ′ comprising an input terminal  22 ′ connected to the transistor  9 ′ and configured for being connected to the output terminal  24  of the connection module  20  of the main current circuit  1 . 
     Clause 10. The thermoelectric assembly according to the preceding clause, wherein 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 additional current circuit  1 ′ are configured for being connected, providing a form-fitting connection. 
     Clause 11. The thermoelectric assembly according to clause 9 or 10, comprising a plurality of additional 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 ′, such that 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 another additional current circuit  1 ′ are configured for being connected to one another, providing a form-fitting connection. 
     Clause 12. The thermoelectric assembly according to any of clauses 9 to 11, wherein the additional current circuit  1 ′ comprises a discharge resistor  15 ′ of the transistor  9 ′ connected in parallel to the transistor  9 ′ and configured for assuring the opening of the transistor  9 ′ when the transistor  9 ′ is no longer powered by the power supply  10 . 
     Clause 13. The thermoelectric assembly according to any of clauses 9 to 12, wherein the additional current circuit  1 ′ comprises a safety resistor  16 ′ connected in series with the port  9   c ′ of the transistor  9 ′ and configured for limiting the current that would go to the additional current circuit  1 ′ from the power supply  10  in the event of a short-circuit failure of the transistor  9 ′. 
     Clause 14. The thermoelectric assembly according to any of the preceding clauses, wherein the main current circuit  1  comprises a discharge resistor  15  of the transistor  9  connected in parallel to the transistor  9  and configured for assuring the opening of the transistor  9  when the transistor  9  is no longer powered by the power supply  10 . 
     Clause 15. The thermoelectric assembly according to any of the preceding clauses, wherein the main current circuit  1  comprises a safety resistor  16  connected in series with the port  9   c  of the transistor  9  configured for limiting the current that would go to the main current circuit  1  from the power supply  10  in the event of a short-circuit failure of the transistor  9 . 
     Clause 16. A 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, 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 . 
     Clause 17. The thermoelectric assembly according to the preceding clause, 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. 
     Clause 18. The thermoelectric assembly according to the preceding clause, 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 . 
     Clause 19. The thermoelectric assembly according to the preceding clause, 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 . 
     Clause 20. The thermoelectric assembly according to any of clauses 17 to 19, 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. 
     Clause 21. The thermoelectric assembly according to the preceding clause, 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 ′. 
     Clause 22. The thermoelectric assembly according to clause 20 or 21, 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. 
     Clause 23. The thermoelectric assembly according to any of clauses 17 to 22, 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. 
     Clause 24. The thermoelectric assembly according to any of clauses 17 to 23, 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. 
     Clause 25. The thermoelectric assembly according to the preceding clause, 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 . 
     Clause 26. The thermoelectric assembly according to clause 24 or 25, wherein the resistive block  14  comprises at least two resistors  14   a ,  14   b  arranged such that they are connected in series. 
     Clause 27. The thermoelectric assembly according to any of clauses 16 to 26, 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  9   c ,  9   c ′ of the transistor  9 ,  9 ′ is eliminated. 
     Clause 28. The thermoelectric assembly according to any of clauses 16 to 27, 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  9   c ,  9   c ′ 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 ′.