[CentOS] Emergency rescue help needed

tech wrote:
> John R Pierce wrote:
>   
>> all the BackUPs I've ever seen have been simple relay switched units.    
>> when the power is on,  you're getting unfiltered power (except for a MOV 
>> based surge protector), when the power is out, it switches to the 
>> "modified square wave" inverter output.
>>     
>
> John,
>
> There are units that change the AC to DC. The DC then charges the 
> batteries and gets changed back to AC for the equipment. These units are 
> very expensive though.
>   

There are online UPS, as you describe.   I don't believe any of them 
have the APC BackUPS brand name on them.   I don't even think APC 
SmartUPS are online, however as I said, the SmartUPS do have power 
conditioners.