| 摘要 |
<p>This describes an open detector circuit essentially composed of comparator circuits (10, 12) with their outputs coupled to each other and to an open collector driver stage (53), driven from the output of the comparators. The detector circuit compares the voltages, such as may be present on twisted wire pairs, connected to its line inputs (30, 31, 34, 35) to set a predetermined line voltage output. If any of the input lines connected to the detector circuit becomes open the detector circuit is held in a specified state indicating suc h opening until it is actively reset. The detector circuit can detect and compare both positive and negative voltages with respect to different voltage sources.</p> |
