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Note added at 4 hrs 18 mins (2005-07-06 16:29:58 GMT)
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or 调节功能很不稳定的调节器

In electrical engineering, a regulator typically refers to a voltage regulator. At the bottom of page 2 of this pdf file, there\'s a description of the feedback mechanism of a regulator. The jerkiness or instability of a low quality regulator is typically caused by the poor design in this feedback loop, among other things.

http://www.national.com/appinfo/power/files/f4.pdf

The output voltage is controlled using a feedback loop, which requires some type of compensation to assure loop stability. Most linear regulators have built-in compensation, and are completely stable without external components. Some regulators (like Low-Dropout types), do require some external capacitance connected from the output lead to ground to assure regulator stability.

Another characteristic of any regulator is that it requires a finite amount of time to \"correct\" the output voltage after a change in load currect demand, This \"time lag\" defines the characteristic called transient response, which is a measure of how fast the regulator returns to steady-state conditions after a load change