基于74HC4046新型的頻率跟蹤電路的研究

摘要：頻率跟蹤是超聲波電源的一個重要特性。本文討論了超聲波清洗機中自動頻率跟蹤的必要性，在介紹超聲波清洗機的主電路原理、PLL鎖相環原理的基礎上，利用單片機檢測超聲電源負載的電流、電壓的相位差，來改變74HC4046 的輸出頻率，完成了變步長頻率跟蹤軟件設計。結果表明，該系統具有很好的頻率跟蹤性能。 敘詞：超聲波電源 鎖相環 頻率跟蹤 74HC4046 變步長 Abstract： Frequency tracking is an important characteristic of ultrasonic power.In this paper,The necessity of frequency tracking in ultrasonic cleaning equipmens is discussed.Based on a introduction on the principle of the mian circuit of the ultrasonic power supply for cleaning equipmens and the principle of PLL ,the output frequency of 74HC4046 is changed by a singlechip measuring the phase difference between volage and current.The software of adaptive tracking technique with varied frequency steps is completed.and　Fast and exact frequency tracking is realized. Keyword：:ultrasonic power PLL frequency-tracking 74HC4046 varied frequency steps