An external clock is a common solution but it requires a digital source equipped with clock input, it exists but it is rare and specific.

(增加)外部的时钟是通常的解决方案，但这要求数字源设备具有时钟输入接口。

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To test for this scenario, rig up an external phase-locked dual-clock source with a knob that intentionally adjusts the phase relationship of the two clocks.

为了测试这个，做一个外部相位锁定的双时钟源，带有两个时钟有意调节相位关系的节点。

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Many clock circuits also work with a resistor and capacitor as low-cost timing components or can be driven from an external source.

许多时钟电路也与电阻器和电容器一起使用作为低成本的时间组分或驱动外部输入。

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