摘要
针对洁牙机的超声电源在工作时难以快速搜索到压电陶瓷换能器谐振点,长时间工作引起大功率器件发热量过大致使系统产生谐振漂移、不能稳定工作的问题,提出了一种基于频率自动搜索与跟踪的超声洁牙机驱动电源设计。该设计通过STM32单片机控制输出步进PWM,基于最大反馈电流设计变步长法快速搜索谐振频率;再利用相位检测技术将换能器输出的电压电流相位差作为电路谐振状态的反馈信号,结合STM32单片机进行PID控制,改变PWM占空比调节电路的振荡频率使系统始终工作于谐振状态,实现谐振频率的自动跟踪,并基于此设计出超声电源电路与控制软件。实验结果表明,该超声电源能快速搜索到换能器的谐振频率,并对谐振频率自动跟踪,使系统能稳定、长时间地工作。
Aiming at the problem that the ultrasonic power supply of the dental descaler is difficult to quickly search the resonant point of the piezoelectric transducer when it is working,and long-term operation causes excessive heat of high-power devices,resulting in reso-nance drift and unstable operation of the system,a design of ultrasonic dental descaler drive power supply based on automatic frequency search and tracking is proposed.The STM32 chip controls the output step PWM,and the variable step method is designed based on the maximum feedback current to quickly search the resonant frequency.Then phase detection technology is used to take the phase differ-ence of the voltage and current output from the transducer as the feedback signal of the resonant state of the circuit,and the STM32 chip is used for PID control to change the oscillating frequency of the PWM duty cycle regulating circuit so that the system always works in the resonant state,realizing the automatic tracking of the resonant frequency.Based on this,the ultrasonic power circuit and control soft-ware are designed.The experimental results show that the ultrasonic power supply can quickly search the resonant frequency and auto-matically track the resonant frequency,so that the system can work stably and for a long time.
作者
陈旺武
刘运毅
CHEN Wangwu;LIU Yunyi(School of Computer and Electronic Information,Guangxi University,Nanning Guangxi 530000,China)
出处
《电子器件》
CAS
北大核心
2023年第6期1541-1545,共5页
Chinese Journal of Electron Devices
关键词
超声电源
频率跟踪
反馈电流
PWM
谐振频率
ultrasonic power supply
frequency tracking
current feedback
PWM
resonance frequency
