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| Thread ID: 115889 | 2011-02-08 00:20:00 | Recommended me a UPS | nedkelly (9059) | Press F1 |
| Post ID | Timestamp | Content | User | ||
| 1176229 | 2011-02-08 20:13:00 | Here's another reason to consider a UPS: Why do power supplies seem to fail after a power outage? Startup is the most stressful time for a typical switchmode power supply . The output filter capacitors as well as the load must be driven while the input voltage is changing - possibly wildly . With careful design, these factors can be taken into consideration . Not all power supplies are designed carefully or thoroughly tested under all conditions . When power is restored, surges, dips, brownouts, and multiple on-off cycles are possible . This is why it is always recommended that electronic equipment be unplugged until power has been restored and is stable . Supplies that are autoselecting with respect to input power are vulnerable to voltages at an intermediate value between their low and high ranges . At some values, they may autoselect the incorrect input range: (From: Mike Diack . ) A subject dear to my heart due to a recent unpleasant experience - Was using a Picturelel videoconference ISDN codec on a job when, because of a powerline fault, the line voltage dropped to 170 volts . The PicTel has a big Onan switchmode PSU which is autoswitching between 100-120 and 200-240 volts . It got confused, and (regrettably) chose the former . . . . with very smelly results . Moral: turn off things with cunning PSUs when brownouts occur (oh yes the airconditioner units got very hot and tripped out, too) ( . repairfaq . org/sam/smpsfaq . htm#smpsppcp" target="_blank">www . repairfaq . org) |
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