a beverage preparation machine can be electrically powered , typically by the mains , via an electric cord . the machine has an internal beverage preparation module covered by a housing . the beverage preparation module is arranged for holding a flavouring ingredient , in particular a pre - portioned ingredient such as an ingredient supplied to such module within a capsule , and circulating a liquid therethrough to form the beverage . the liquid , e . g . water , may be stored and supplied to the beverage preparation module from a tank . the beverage , upon formation , can be dispensed via an outlet to a dispensing area , e . g . a support for holding a user cup or mug . the dispensing area may include a first cup support , e . g . a support for espresso cups , that is movable away from under outlet so as to give access to a lower second cup support for larger cups or mugs , e . g . for dispensing lungos or extra - large beverages . the lower cup support may be connected to a base of machine . suitable movable cup supports are for example disclosed in ep 1867260 and in wo 2009 / 074557 , the contents of which are hereby incorporated by way of reference . the machine also includes a steam and / or hot water generator for delivering such steam and / or hot water via an opening of tube , e . g . for the preparation of frothed milk and / or tea . adjacent to the beverage preparation module , machine may have a collector for used flavouring ingredient , e . g . ground coffee or tea upon brewing , for instance contained within capsules . collector may be positioned underneath the beverage preparation module to collect upon beverage preparation the used flavouring ingredient evacuated to collector , e . g . by gravity . suitable collectors are for example disclosed in wo 2009 / 074559 and in wo 2009 / 135869 , which are hereby incorporated by way of reference . the machine has a handle movable between : a transfer position for loading the ingredient , e . g . within a capsule , into the module and / or evacuating such ingredient from the module ; and a circulation position for circulating the liquid through the ingredient . typically , handle actuates an ingredient holder with an ingredient chamber , such as a brewing unit , of the beverage preparation module from : a transfer position ( not shown ) for insertion of the flavouring ingredient into the holder and / or evacuation of this ingredient therefrom ; and a circulation position for circulating the liquid through this ingredient in the ingredient holder to form the beverage . typically , the ingredient holder , e . g . a brewing unit , has two relatively movable parts that are moved apart for opening the ingredient holder into the transfer position and moved together for closing the ingredient holder into the circulation position . in the circulation position ( not shown ), the ingredient holder may tightly enclose the flavouring ingredient to ensure proper guidance of the liquid through the ingredient . in the circulation position , the handle may rest on or in a top face of machine . in particular the handle can be flush with the housing . furthermore , the machine includes a user - interface for initiating circulation of the liquid through the flavouring ingredient in the beverage preparation module . the beverage preparation module typically includes one or more of the following components : a ) the ingredient holder , such as a brewing unit , for receiving the flavouring ingredient of this beverage , in particular a pre - portioned ingredient supplied within a capsule , and for guiding an incoming flow of liquid , such as water , through this ingredient to beverage outlet ; b ) an in - line heater for heating this flow of liquid to be supplied to the ingredient holder ; c ) a pump for pumping this liquid through the in - line heater ; d ) one or more fluid connecting members for guiding this liquid from a source of liquid , such as tank of liquid , to beverage outlet ; e ) an electric control unit , in particular comprising a printed circuit board ( pcb ), for receiving instructions from a user via an interface and for controlling the in - line heater and the pump ; and f ) one or more electric sensors for sensing at least one operational characteristic selected from characteristics of the ingredient holder , the in - line heater , the pump , liquid reservoir , ingredient collector , a flow of this liquid , a pressure of this liquid and a temperature of this liquid , and for communicating such characteristic ( s ) to the control unit . an inline heater according to an embodiment is illustrated on fig1 . the inline heater comprises a body 8 with an integrated water circuit . the body 8 may be made of aluminium : the aluminium body has a sufficient thermal capacity to dampen energy variations , though limited to minimise the heat - up time at start - up from room or rest temperature . the water circuit comprises a liquid inlet 10 , a liquid outlet 12 , and a liquid pipe 14 in - between fluidically connecting the inlet to the outlet . the water pipe can be formed by a molded inox water pipe embedded in the body . the water pipe can also be formed by a coated liquid channel formed in the body . the external shape of the body illustrated on fig1 is a cylinder , with a diameter d 1 of 75 mm and a height h 1 of 16 mm , having one of its ends covered by a surface heating element 16 . the heater comprises a surface heating element 16 that is thermally and mechanically coupled to the body . typically , the surface heating element 16 is a thick film . in particular , the thick film may be printed on an inox plate which is soldered to the aluminium diecast body . this coupling is designed for optimal heat transfer , for good mechanical stability and for taking the forces , which result from the different thermal length dilatations of aluminium body and thick film plate . the surface heating element 16 comprises at least two heat circuits . each heat circuit has a separate control circuit , so as to allow the activation / deactivation of said heat circuit independently of the others heat circuits . each heat circuit is capable of delivering an heating power that is smaller than the heating power that the surface heating element is capable of delivering . as a consequence , a split of the heat power to multiple ( typically 2 for the espresso applications , e . g . prepared from a capsule such as a nespresso capsule ) can be obtained to follow the flicker standards . the power split between the two heating circuits can be a 50 %/ 50 % repartition of the heating power between the circuits , or any repartition from 15 %/ 85 % to 85 %/ 15 %. the total heating power of the surface heating element is typically comprised between 600 w and 2000 w . water heater for water flows of 0 up to 3 . 5 ml / s two resistive heating circuits printed on a thickfilm plate , with a total power of about 1200 w power split of heat circuits between 300 w / 900 w up to 600 w / 600 w possible heat density in inox water pipe : 0 . 1 w / mm ̂ 2 , allowing no steaming up to 95 ° c . maximum temperature of outlet heat up time from 20 ° c . to 90 ° c . below 20s ( ready for coffee brewing ) power rate for heat up ( power / gramm of total heater mass ): over 5 w / g an inline heater according to another embodiment is illustrated on fig2 . the inline heater comprises a body 28 with an integrated water circuit . the body 28 may be made of aluminium : the aluminium body has a sufficient thermal capacity to dampen energy variations , though limited to minimise the heat - up time at start - up from room or rest temperature . the water circuit comprises a liquid inlet 20 , a liquid outlet 22 , and a liquid pipe 24 in - between fluidically connecting the inlet to the outlet . typically the liquid pipe has an helicoidal shape . the water pipe can be formed by a molded inox water pipe embedded in the body . the water pipe can also be formed by a coated liquid channel formed in the body . the external shape of the body illustrated on fig2 is a cylinder , with a height h 2 of 65 mm and an external diameter of d 5 of 50 mm ( d 2 = 20 mm , d 3 = 30 mm , d 4 = 42 mm ). the heater comprises an heating element 29 including a cylindrical heat cartridge 29 a and a wrapped heat cartridge 29 b . the cylindrical heat cartridge 29 a and the wrapped heat cartridge 29 b are controlled by two electrical circuits so as to allow the activation / deactivation of the cylindrical heat cartridge 29 a and the wrapped heat cartridge 29 b independently . the cylindrical heat cartridge 29 a is controlled by a first circuit 23 a , 23 b , whereas the wrapped heat cartridge 29 b is controlled by a second circuit 23 c , 23 b , the two circuits sharing a common reference potential / neutral 23 c . each cartridge 29 a , 29 b is capable of delivering an heating power that is smaller than the heating power that the surface heating element is capable of delivering . as a consequence , a split of the heat power to multiple ( typically 2 for the espresso applications , e . g . prepared from a capsule such as a nespresso capsule ) can be obtained to follow the flicker standards . the power split between the two heating cartridge can be a 50 %/ 50 % repartition of the heating power between the circuits , or any repartition from 15 %/ 85 % to 85 %/ 15 %. the total heating power of the surface heating element is typically comprised between 600 w and 2000 w . inline heaters according to other embodiments are illustrated on fig3 a and 3 b . the inline heater comprises a body 38 with an integrated water circuit . the body 38 may be made of aluminium : the aluminium body has a sufficient thermal capacity to dampen energy variations , though limited to minimise the heat - up time at start - up from room or rest temperature . the water circuit comprises a liquid inlet 30 , a liquid outlet 32 , and a liquid channel 34 in - between fluidically connecting the inlet to the outlet . typically the liquid channel 34 is formed in the body 38 . in particular , the liquid channel 34 is coated . the external shape of the body illustrated on fig3 a / 3 b is a cylinder , with a height h 3 of 65 mm . for the embodiment illustrated in fig3 a , the body has an external diameter of d 7 of 40 mm ( d 6 = 20 mm , d 7 = 36 mm ). for the embodiment illustrated in fig3 b , the body has an external diameter of d 8 of 50 mm ( d 6 = 20 mm , d 7 = 36 mm ). the heater comprises an heating element 39 including a cylindrical heat cartridge 39 a . the heating element 39 of the embodiment illustrated on fig3 b comprises a thick film heater 39 b that is thermally and mechanically coupled to the body . the thick film may be printed on a steel cylinder which is mounted on the body . the cylindrical heat cartridge 39 a and the thick film heater 39 b are controlled by two electrical circuits so as to allow the activation / deactivation of the cylindrical heat cartridge 39 a and the thick film heater 39 b independently . the cylindrical heat cartridge 39 a is controlled by a first circuit 33 a , 33 b , whereas the thick film heater 39 b is controlled by a second circuit 33 c , 33 b , the two circuits sharing a common reference potential / neutral 33 c . each element 39 a , 39 b is capable of delivering an heating power that is smaller than the heating power that the surface heating element is capable of delivering . as a consequence , a split of the heat power to multiple ( typically 2 for the espresso applications , e . g . prepared from a capsule such as a nespresso capsule ) can be obtained to follow the flicker standards . the power split between the two heating element can be a 50 %/ 50 % repartition of the heating power between the circuits , or any repartition from 15 %/ 85 % to 85 %/ 15 %. the total heating power of the surface heating element is typically comprised between 600 w and 2000 w . the heating element 39 of the embodiment illustrated on fig3 b comprises a wrapped heat cartridge 39 c . the wrapped heat cartridge 39 c may be molded in metal cylinder mounted around the body . the cylindrical heat cartridge 39 a and the wrapped heat cartridge 39 c are controlled by two electrical circuits so as to allow the activation / deactivation of the cylindrical heat cartridge 39 a and wrapped heat cartridge 39 c independently . the cylindrical heat cartridge 39 a is controlled by a first circuit 33 a , 33 b , whereas wrapped heat cartridge 39 c is controlled by a second circuit 33 c , 33 b , the two circuits sharing a common reference potential / neutral 33 c . each element 39 a , 39 b is capable of delivering an heating power that is smaller than the heating power that the surface heating element is capable of delivering . as a consequence , a split of the heat power to multiple ( typically 2 for the espresso applications , e . g . prepared from a capsule such as a nespresso capsule ) can be obtained to follow the flicker standards . the power split between the two heating element can be a 50 %/ 50 % repartition of the heating power between the circuits , or any repartition from 15 %/ 85 % to 85 %/ 15 %. the total heating power of the surface heating element is typically comprised between 600 w and 2000 w . the heat power will be distributed by switching on and off the two power circuits of a heater according to the invention as illustrated in fig1 to 3 . different options are available for a heater with two different power circuits , such as 400 w / 800 w . the determination which regulation option is the best for a specific flow and water temperature target at the exit of the thermoblock will be made with a pre - calculation of the needed heat power : power need = water flow *( t exit − t entry )* thermal capacity of water with this pre - calculation the optimal thermal regulation algorithm can be predetermined , and a smooth and precise temperature regulation can be achieved . for respecting the flicker standards , a simultaneous switching on or off of both circuits has to be avoided decreased heat up time to operating temperature from room or rest temperature thermo regulation possible according to barrista espresso temperature quality standards and as well within flicker public regulations . good regulation dynamics low mass ( below 250 g total heater mass ) important features of the invention may include : two heating circuits allowing high quality thermo regulation ; low thermal mass allowing fast heat up times ; dynamics adjustable by adding or descreasing weight of alu body ; specific know how for connection of thickfilm plate to aluminium heater body .
a dynamic double - circuit in - line heater is disclosed , as well as a machine containing the heater and a method of operating the machine .