An induction heating device includes: a working coil, an inverter, a current transformer, a current detecting circuit, a voltage detecting circuit, an AND circuit, and a controller. The induction heating device may detect presence or absence of an object and a material of the object based on a magnitude of resonance current applied to the working coil and a phase difference between the resonance current and a voltage applied to a switching element of the inverter.

A cooking apparatus and a method for controlling the same. The cooking apparatus may include a heating coil operable by an induction heating method, an inverter configured to provide a driving power to the heating coil, a sensing coil positioned at an upper portion or a lower portion of the heating coil, a sensing circuit configured to provide a test power to an end of the sensing coil and sense a magnitude of power that is output at other end of the sensing coil, and a processor configured to identify whether an object to be heated is disposed at an upper portion of the sensing coil based on the magnitude of power sensed by the sensing circuit, and based on the disposition of the object to be heated being identified, control the inverter to apply the driving power to the heating coil.

Induction cooktops and operational methods are provided herein. A method of determining material composition of cookware on an induction cooktop can include determining that a piece of cookware is on the induction cooktop, inducing a current within the piece of cookware with an induction coil of the induction cooktop, and obtaining a peak induction coil current, a smoothed input line current, and a phase shift of current flowing in the induction coil. The method can further include comparing the peak induction coil current, the smoothed input line current, and the phase shift each to a set of predetermined ranges, and determining candidate material compositions for the cookware based on the comparing of each of the peak induction coil current, the smoothed input line current, and the phase shift.

A burner assembly for a cooktop includes a housing defining a first group of radially-spaced fuel outlets extending from an interior to an exterior of the housing, a first aperture extending through the housing and spaced outward of the first group of outlets, and a second group of radially-spaced fuel outlets extending from the interior to the exterior and spaced outward of the first aperture. A first switch assembly is mounted within the housing and includes a first pin extending upwardly through the first aperture to an end positioned above the housing. The end of the first pin is moveable in a first direction inward and outward with respect to the housing to control a direction of a first portion of a flow of fuel to the second group of outlets. A second portion of the flow of fuel is continuously directed to the first group of outlets.

Disclosed is a device configured to inductively heat one or more objects and to wirelessly transfer power to one or more objects. The device includes a first working coil, an inverter unit configured to cause a resonant current to flow in the first working coil by performing a switching operation, a first detection unit connected to the first working coil and configured to detect the resonant current applied to the first working coil, and a control unit configured to: determine whether a target object is located at a location corresponding to the first working coil by controlling operation of the inverter unit and the first detection unit; or to control output of the first working coil.

An induction heating device includes first and second working coils connected to each other electrically in parallel, an inverter unit configured to cause a resonant current to flow in at least one of the first working coil or the second working coil, a first semiconductor switch configured to turn on and off the first working coil; a second semiconductor switch configured to turn on and off the second working coil; and a control unit configured to apply the resonant current to the first working coil or the second working coil by controlling the inverter unit, the first semiconductor switch, and the second semiconductor switch, and, based on a number of pulses or a frequency of the resonant current, to detect whether a target object is located at a location corresponding to the first working coil or the second working coil.

An induction heating device includes: a working coil set including a first working coil connected to a first resonant capacitor and a second working coil connected to a second resonant capacitor; an inverter that performs a switching operation to apply a resonant current to at least one of the first or second working coil; a current transformer that adjusts a magnitude of the resonant current and that transmits the resonant current having the adjusted magnitude to the working coil set; a first relay that selectively connects a first end of the second working coil to the current transformer or the second resonant capacitor; a second relay that selectively connects a to second end of the second working coil to an end of the first working coil or the second resonant capacitor; and a control unit configured to control operations of the inverter and the first and second relays, respectively.

The present invention relates to a method for controlling a cooking zone (16) of an induction cooking hob, wherein said cooking zone (16) comprises at least one induction coil (16) and is supplied by a generator (14) including a power switch. The method is performed by controlling the power switch by a gate driving signal (18) including a deactivation pulse length (Toff) and an activation pulse length (Ton). A switching period (T) of the gate driving signal (18) is given by the sum of the activation pulse length (Ton) and deactivation pulse length (Toff). A driving frequency (f) of the power switch is the reciprocal value of said switching period (T). The deactivation pulse length (Toff) depends on the resistance (28) and the inductance (30) of the induction coil (16). The activation pulse length (Ton) is varied according to a requested power for the cooking zone (16). A series of constant activation pulse length (Ton) is activated in order to determine the optimal deactivation pulse length (Toff).

Induction cooktops and operational methods are provided herein. A method of determining presence of compatible cookware on an induction cooktop can include receiving a request to heat the induction cooktop, controlling at least one switching device to induce a current within an assumed piece of cookware with an induction coil of the induction cooktop, sensing a voltage associated with the at least one switching device, the voltage being proportional to current flowing in the induction coil, determining that the sensed voltage includes one or more voltage spikes above a first threshold, and determining that the assumed piece of cookware is absent when the sensed voltage includes the one or more voltage spikes.

An induction heating device includes a working coil, an inverter, an inverter driving unit configured to apply a switching signal to the inverter to enable the inverter to perform a switching operation, a control unit configured to generate and apply a control signal to the inverter driving unit to cause the inverter driving unit to generate the switching signal based on the control signal, and a determination unit configured to determine a type of an object disposed on the induction heating device based on (i) a first resonant current value measured from the working coil in response to operation of the inverter by the switching signal having a first operation frequency and (ii) a second resonant current value measured from the working coil in response to operation of the inverter by the switching signal having a second operation frequency.