On Aug 12, 9:21 am, Robert Redelmeier wrote:
You overstate your case. Both "Standby" and "power conditioning"
UPSes are readily abailable in the smaller sizes:

So where is the double conversion UPS selling for $85? The app note
is simply a summary of names for each type of UPS. It says nothing
about a double conversion UPS costing only $85. And it forgets to
mention other paths of noise and interference that even completely
bypass the UPS. And it does not discuss functions that all
electronics contain so that every very dirty electricity from $85
UPSes is completely irrelevant.

What must that router do? Its power supply must be so robust that
even an $85 UPS in battery backup mode outputing dirt - 200 volt
square waves and a spike of less than 270 volts - is completely
irrelevant to the router. Why did an APC app note forget to mention
those numbers; forget to mention what electronics power supplies must
make irrelevant?

Simpler solutions first identify a problem rather than throwing a
$500 UPS to fix what may even be, instead, a defective $50 router.
Nothing else crashes and locks? Somehow that also is not relevant?
Somehow we know it must be an AC electric problem? A conclusion
based in speculation. Somehow an $85 UPS does what a $500 UPS does?
Where does the APC app note say that? Why does it not say so much
that is relevant to this router problem?