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