Load Detection Circuit for Hybrid Induction Cooker of Inductive Heating and Wireless Power Transfer

The induction cooker can be used for hybrid purpose of pan heating and wireless power transfer for the kitchen appliance. The load detection circuit and method using variation of resonant frequency is proposed. The load detection capacitor or magnetic coil of receiver (Rx) product generates the resonant frequency changes. The induction cooker measures the coil current zero crossing time for load detection. The circuit can detect the existence and kind of kitchen appliance. The 2kW power induction cooker was fabricated to verify the proposed circuit.