Investigation of Electrical Transient Behavior for Ultrasonic Transducer in on/off Cycles

This paper investigates a theoretical analysis of electrical transient responses of a bolt-clamped Langevin ultrasonic transducer (BLT) and its verifications based on simulations and experiments during on/off transient states immediately after turning on/off. The simulations are determined by a power electronic simulator originally designed for power converters and motor drives. The responses include the open-circuit voltage, the terminal current, the motional current and the mechanical power loss. A linear equivalent circuit model with the initial conditions is stated first. This model is used to derive the responses characterized by simple closed-form equations. The off transient state as specified by the initial conditions regarding switching-off time of an ac sine source for the drive of the BLT is related to cyclic behavior. The derived responses are further checked by simulations and experiments. To obtain the experiments, a test system which contains an ac power supply, a digital oscilloscope and a control switch is needed. Finally, characteristics of the responses and effects of switching-on/off times of the ac sine source on the characteristics are discussed. The characteristics comprise the dc/ac time constants and the maximum/minimum wave amplitudes for the BLT during on/off transient states.