Development of Handheld Ultrasonic Spot Welding Machines

As the resonance frequency of the ultrasonic vibration system drifts according to the different operating condition, Ultrasonic power supply based on MSP430 is designed in this thesis. Series inductance and parallel capacitance are used to match the vibration system and series resonance technology used in primary side of inverter transformer can reduce switch loss. ADC module in MSP430 is used to get frequency shift, and PWM module is made to adjust the operating frequency of TL494, which can realize closed loop control of frequency tracking. The results of experiments show that the method designed in this thesis has high detection accuracy, high speed dynamic response and high stability of frequency tracking.