An inductive heating device (1) comprises: a device housing (10), a DC power source (11), a power supply electronics (13) comprising a DC/AC inverter (132) including a Class-E power amplifier with a transistor switch (1320), a transistor switch driver circuit (1322), and an LC load network (1323) configured to operate at low ohmic load (1324), the LC load network (1323) comprising a shunt capacitor (CI) and a series connection of a capacitor (C2) and an inductor (L2), and a cavity (14) arranged in the device housing (10), the cavity (14) having an internal surface shaped to accommodate at least a portion of the aerosol-forming substrate (20), wherein the cavity (14) is arranged such that the inductor (L2) is inductively coupled to the susceptor (21) of the aerosol-forming substrate (20) during operation.

A cooktop appliance is provided. The cooktop appliance includes an induction heating system having an induction heating element, a power supply circuit, a battery assembly, and a controller. The induction heating element is operable to inductively heat a load with a magnetic field. The power supply circuit includes an inverter and is coupled to an alternating current (AC) power supply configured to supply a power signal to the induction heating system. The battery assembly is coupled to the power supply circuit via a switching element and is configured to provide a supplemental power signal to the induction heating system. The controller is operably coupled to the power supply circuit and the battery assembly and is configured to control operation of the induction heating system based, in part, on a power requirement of the induction heating system that corresponds to a total power output required by the induction heating system.

A heating device includes a first capacitor, a first switch, a second switch, a second capacitor, a third capacitor, a coil and a controller. The first and second switch are coupled in series at a first node, and are coupled with the first capacitor in parallel. The second capacitor is coupled to the first switch. The third capacitor is coupled to the second switch, and is coupled to the second capacitor at a second node. The coil is coupled between the first and the second node. The controller outputs a first and a second control signal to the first switch and the second switch, respectively. After the heating device received a voltage and a starting command, the controller outputs the first and the second control signal to turn on or off the first and the second switch respectively. The duty cycle of the first signal is lower than 50%.

A heating device includes a first capacitor, a first switch, a second switch, a second capacitor, a third capacitor, a coil and a controller. The first and second switch are coupled in series at a first node, and are coupled with the first capacitor in parallel. The second capacitor is coupled to the first switch. The third capacitor is coupled to the second switch, and is coupled to the second capacitor at a second node. The coil is coupled between the first and the second node. The controller outputs a first and a second control signal to the first switch and the second switch, respectively. After the heating device received a voltage and a starting command, the controller outputs the first and the second control signal to turn on or off the first and the second switch respectively. The duty cycle of the first signal is lower than 50%.

A heating device includes a resonant circuit, a detection unit and a control unit. The resonant circuit includes an inverter circuit and a resonant tank. The inverter circuit provides a resonant tank current and a resonant tank voltage. The resonant tank includes a heating coil, a resonant tank capacitor, a resonant tank equivalent inductor and a resonant tank equivalent resistor. The detection unit calculates an inductance of the resonant tank equivalent inductor according to a capacitance of the resonant tank capacitor, a resonant period and a first expression. The detection unit calculates a resistance of the resonant tank equivalent resistor according to the inductance of the resonant tank equivalent inductor, a time change value, a reference voltage value, a negative peak voltage value and a second expression.

A heating device includes a first capacitor, a first switch, a second switch, a second capacitor, a third capacitor, a coil and a controller. The first and second switch are coupled in series at a first node, and are coupled with the first capacitor in parallel. The second capacitor is coupled to the first switch. The third capacitor is coupled to the second switch, and is coupled to the second capacitor at a second node. The coil is coupled between the first and the second node. The controller outputs a first and a second control signal to the first switch and the second switch, respectively. After the heating device received a voltage and a starting command, the controller outputs the first and the second control signal to turn on or off the first and the second switch respectively. The duty cycle of the first signal is lower than 50%.

An inductive heating device (1) for heating an aerosol-forming substrate (20) comprising a susceptor (21) comprises: a device housing (10), a DC power source (11) for providing a DC supply voltage (V.sub.DC) and a DC current (I.sub.DC), a power supply electronics (13) comprising a DC/AC converter (132) comprising an LC load network (1323) comprising a series connection of a capacitor (C2) and an inductor (L2) having an ohmic resistance (R.sub.Coil), a cavity (14) in the device housing (10) for accommodating a portion of the aerosol-forming substrate (20) to inductively couple the inductor (L2) to the susceptor (21). The power supply electronics (13) further comprises a microcontroller (131) programmed to determine from the DC supply voltage (V.sub.DC) and from the DC current (I.sub.DC) an apparent ohmic resistance (R.sub.a), and from the apparent ohmic resistance (R.sub.a) the temperature (T) of the susceptor (21). It is further programmed to monitor changes in the apparent ohmic resistance (R.sub.a) and to detect a puff when a decrease of the apparent ohmic resistance (R.sub.a) is determined which is indicative of a temperature decrease of the susceptor (21) during a user inhalation.

An inductive heating device (1) for heating an aerosol-forming substrate (20) comprising a susceptor (21) comprises: a device housing (10), a DC power source (11) for providing a DC supply voltage(V.sub.DC) and a DC current (I.sub.DC), a power supply electronics (13) comprising a DC/AC converter (132), the DC/AC converter (132) comprising an LC load network (1323) comprising a series connection of a capacitor (C2) and an inductor (L2) having an ohmic resistance (R.sub.Coil), a cavity (14) in the device housing (10) for accommodating a portion of the aerosol-forming substrate (20) to inductively couple the inductor (L2) of the LC load network (1323) to the susceptor (21). The power supply electronics (13) further comprises a microcontroller (131) to determine from the DC supply voltage (V.sub.DC) and the DC current (I.sub.DC) an apparent ohmic resistance (R.sub.a), and from the apparent ohmic resistance (R.sub.a) the temperature (T) of the susceptor (21).

Problem

Provided is a heating coil for high-frequency heater that is not easily damaged, has good cooling efficiency for a material to be worked, and can be inexpensively and easily manufactured having the same property with good reproducibility during manufacturing even when output of the high-frequency power supply is increased.

Solution

A heating coil 1 is integrally formed by a modeling method repeating laying, melting, solidifying, and laminating of a powder containing a conductive material based on three-dimensional data, and includes a pair of plate-shaped grounding portions 2a, 2b, a pair of plate-shaped supporting portions 3a, 3b, and an annular heating unit 4. The pair of grounding portions 2a, 2b are for contact with an electrode through which a high-frequency current is flowed. The pair of plate-shaped supporting portions 3a, 3b are disposed to be perpendicular to the respective grounding portions 2a, 2b. The annular heating unit 4 is disposed to connect distal ends of the supporting portions 3a, 3b to one another. The annular heating unit 4 includes a first cooling medium flow path 5 for cooling the material to be worked W after heating and a second cooling medium flow path 6 for cooling the heating unit 4 itself separately.

An induction cooking hob and method for assigning induction coils of the hob, so that each coil corresponds with a unique number or identity. The method includes; setting a load onto the hob, so that the load covers only one of the coils, which is provided for a first unique number or first identity; activating a pot detection device for all coils of hob; identifying the coil covered by the load; assigning the first number or identity to the covered coil; storing the unique number or identity in conjunction with the covered induction coil; setting the load onto a further one of the coils, which is provided for a second unique number or second identity; repeating the steps c) to f) for the further coil and second number or identity; and repeating the steps b) to f) for all other coils and corresponding unique numbers or corresponding identities.