| 摘要 |
<p>A circuit for detecting a predefined reoccurring phase point in the wave form of periodic electrical signal has an input stage which rectifies the signal into first and second complementary signals. A Schmitt circuit has an input connected to the rectifier stage and produces a first intermediate signal in response to the voltage of the first complementary signal. A complementary Schmitt circuit is connected to the rectifier stage and produces a second intermediate signal in response to the voltage of the second complementary signal. An output stage that is connected to the Schmitt circuit and the complementary Schmitt circuit, responds to the first and second intermediate signals by producing an indication of each occurrence of the reoccurring phase point in the periodic electrical signal.</p> |
