New PSU Test Criteria Suggestion

Recent discussions about UPSs got me to thinking about the ATX Form Factor "Voltage Hold-up Time" requirement:

Quote:

Originally Posted by ATX Power Supply Design Guide for Desktop Platform Form Factors, Revision 1.31, April 2013, Section 3.2.9 The power supply should maintain output regulations per Table 5 despite a loss of input power at the low-end nominal range-115 VAC / 47 Hz or 230 VAC / 47 Hz – at maximum continuous output load as applicable for a minimum of 17 ms.

I think this is a critical requirement and would like to see this tested in future PSU reviews to see how well today's PSUs are meeting this requirement. I suspect some are holding for longer than 17ms. But I bet some, perhaps even some highly rated PSUs, would fail.



17ms is much faster than any "flicker" of the lights humans might detect. I fear the inability of some PSUs to hold power long enough is why some (even better) UPSs fail to cutover in time to keep the connected computers from hard crashing.



I note 33.3 milliseconds is the amount of time one frame lasts in 30 fps video.



Any chance of adding this test to reviews?

New PSU Test Criteria Suggestion