| 摘要 |
<p>This invention relates to an improved laser printer power supply that maintains 24-, 12-, and 5-volt DC power to run exhaust fans (14) for a brief period after the power switch (S1) is turned off. These fans (14) remove undesirable ozone from the photo-conducting print drum so as to extend the life of the photo-conductor. The circuits utilize a timer circuit and an optically isolated photo-diac (31,32) to turn a power triac (30) on and off. <IMAGE></p> |
