Lg Electronics Inc.

Seonho Jeon

Seongho Son

Younghwan Kwack

Jongseong Ji

Chuhyoung Cho

Kyelyong Kang

A protection circuit of a resonant converter including first and second switches, where the protection circuit comprises: a comparator configured to (i) compare a direct current (DC) link voltage of the resonant converter with a voltage across both ends of one of the first or second switches and (ii) output one or more signals based on the comparison, and a microcomputer configured to detect whether zero voltage switching is performed, based on the one or more output signals from the comparator.

Protection circuit of resonant converter and operation method thereof

An induction heating type cooktop includes a case, an upper plate coupled to a top of the case and configured to support an object, a working coil disposed inside the case and configured to heat the object, a thin film arranged at a top surface of the upper plate or a bottom surface of the upper plate, at least one temperature sensor configured to measure a temperature of at least one of components of the induction heating type cooktop, the components including the thin film, and a microcontroller unit (MCU) configured to drive the working coil and to control an output of the working coil based on whether the temperature satisfies at least one condition that is preset for the at least one of the components.

Induction heating type cooktop with output control algorithm based on temperature of multiple components

An induction heating type cooktop includes: a case, a cover plate coupled to a top of the case and having an upper plate that is configured to support a target object, a thin film disposed on at least one of a top of the upper plate or a bottom of the upper plate, a working coil provided in the case and configured to inductively heat the thin film, a memory storing information on one or more correlations between a temperature of the thin film and a plurality of components of an equivalent circuit associated with the thin film, the plurality of components including an inductor component and a resistor component, and a controller configured to operate the working coil and determine estimated temperature information corresponding to the inductor component and the resistor component of the equivalent circuit.

Induction heating type cooktop for estimating temperature of thin film

An induction heating type cooktop includes an upper plate coupled to a top side of a case and configured to place an object to be heated on a top of the upper plate, a working coil disposed inside the case to heat the object, a thin film disposed on at least one of a top surface or a bottom surface of the upper plate, an insulator disposed between the bottom surface of the upper plate and the working coil, and a temperature sensor configured to measure a temperature of at least one of the thin film or the upper plate by a plurality of thermocouples.

Induction heating type cooktop for enabling high temperature detection

Provided is a resonant power conversion apparatus including a gate control circuit that controls a first switch to enter an On state and a second switch to enter an Off state at a first stage and controls the first switch to enter the Off state and the second switch to enter the On state at a second stage, a first current transformer that applies current to the first switch at the first stage and applies current to the second switch at the second stage, a load connected to the first current transformer in series, a second current transformer connected to the second switch, and a microcontroller unit (MCU) that determines whether to be zero voltage switching or non-zero voltage switching based on a current flowing in the first current transformer and the second current transformer in a process of transitioning from the first stage to the second stage.

Circuit for detecting failure of zero voltage switching

An induction heating device includes an induction heating circuit, a sensor configured to measure current applied to the induction heating circuit, and a controller. The controller includes: a switch driving unit configured to control operation of an inverter unit and to allow a resonance of the current, a container sensing unit, and a control unit. The container sensing unit is configured to: convert a first current value before the resonance into a first voltage value; control the switch driving unit to charge a working coil; compare the first voltage value with a resonance reference value; convert a second current value after the resonance into a second voltage value; generate one or more output pulses; and compare the second voltage value with a count reference value. The control unit is configured to determine whether an object is present on the working coil based on the one or more output pulses.

Induction heating device performing container sensing function

A method is provided for operating a resonant power conversion apparatus The method may include charging a capacitor connected to a power source in parallel, and determining a discharge time point and a discharge period of a discharge circuit, where the discharge circuit includes a resistor and a switch connected in series and is connected to the capacitor in parallel. The method may also include outputting, by a switch control circuit, a switch control signal by determining the switch control signal based on the discharge time point and the discharge period, and discharging the charged capacitor through the resistor based on the switch control signal applied to the switch. A resonant power conversion apparatus for performing the above-described method is provided.

Growing community of inventors

Seoul, South Korea

Seonho Jeon