| 摘要 |
<p>The brightness fluctuation test monitor, for a tv crt screen, consists of a handheld unit that the test engineer positions over the screen. Brightness variations are indicated by a loudspeaker or lamp or both. A photodetector (1) receives light from the screen and its output is compared (3) with a reference. The comparator's output drives the brightness indicator (8, 9, 11). A threshold trigger (6, 7) may be used to cut-in the brightness indicator at a given level. The test monitor can be left in front of the screen for long periods to indicate acoustically (or optically) to the engineer when an infrequent fault occurs.</p> |
