Design and Performance of a Miniature Electromagnetic Induction Heating System

Currently, research on electromagnetic induction heating technology mainly focuses on large-scale, high-power equipment with high-voltage power supplies. However, there is a significant gap in studies on miniaturized applications, especially low-power heating devices powered by 3.7V lithium ion batteries and the heating of small-sized materials. To fill this research gap, this paper conducts the design and experimental investigation of the operational performance of a compact electromagnetic induction heating system. The system adopts a full-bridge inductance-capacitance (LC) series-resonant circuit as the main circuit structure. Instead of relying on the complex structures of traditional transformers and LLC circuits for impedance matching, it skillfully adjusts the inverter frequency by fine-tuning the resonant capacitance, effectively achieving load impedance matching. Experimental results show that when the battery supplies an output current of 4.6A, the heated device can rapidly reach the target temperature of 250°C within just 11 seconds. Moreover, during a 5 minutes thermal insulation period of system operation, the temperatures of all NMOS transistors and the induction coil remain well below 50°C, highlighting the excellent thermal stability and reliability of the system.