[asterisk-users] Quiet 24 port POE gig switch

[Wilton Helm]

>A modern switched mode PSU ought to be more than 90% efficient,

In theory, yes, in practice, not likely.  It is harder to get high efficiency from an isolated supply than a non-isolated one.  I get ads from IC manufacturers all the time about there 90 to 95% efficient solutions, but these are boost or buck regulators--non-isolated.  State of the art in commercial practice for isolated supplies is around 80 to 85%, and typical commercial practice is more like 70 to 80%.  Now you have more like 60 watts of heat radiating from this power supply.  Go stick a 60 watt light bulb (incandescent) in a small metal box and see how easy it is to keep cool.

Wilton
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