Let us talk about the fault condition and repair method of the induction heater today. I hope I can help you. Induction heater (abbreviated as inductor) is an inductance coil, which can satisfy various heating processes through rational distribution of inductive magnetic field. It is a key component of various induction heating processes and it is also an essential component. Its performance is directly related to heating. The craftsmanship is excellent, and the sensor must be manufactured according to the heating process. Due to the wide variety of induction heating processes, the variety of sensor specifications is correspondingly large. The failure of the solid-state high-frequency heating device is mainly reflected in the series resonant inverter. The key factor that determines the quality of the solid-state high-frequency heating device is the suppression of parasitic oscillation during the switching process. There is a parasitic capacitance between the drain-source and drain-gate of the MOS transistor. At the same time, parasitic inductance exists in the connection between the inverter bridge and each MOS transistor and the connection between the DC terminal and the inverter bridge.

Because the switching speed of the MOS transistor is fast, the parasitic inductance of the transient line at the instant of the switching will generate parasitic oscillations of the MOS transistor with extremely high frequency parasitic oscillations. If the compensation measures are not properly implemented, the MOS transistor must be greatly turned off during shutdown. Voltage, and reduce the effective operating voltage of the MOS tube. What is more serious is that at the instant of switching, the high-frequency parasitic oscillating voltage in the main circuit is coupled to the input of the MOS transistor through the parasitic capacitance between the drain and the gate. Since the amplitude of the driving signal is only a dozen volts, the main circuit A very small high-frequency parasitic oscillation, coupled to the input via a Miller capacitor, can cause a false turn-on of the turn-off tube, resulting in a through-pass between the upper and lower arms.

yqkexin Mai 15 · blogs+tags induction heater