[mythtv-users] Loss of Service Recognition -- Nifty!

Brian Wood beww at beww.org
Sat Mar 18 17:15:05 UTC 2006

On Mar 18, 2006, at 10:01 AM, Tom Burt wrote:

> On Saturday 18 March 2006 15:51, Brian Wood wrote:
>> Unless your cable box, sat receiver or RF amplifier etc. are *not* on
>> the UPS. Even a short blip could cause a channel change or power down
>> and your recording would be "adversely affected".
>> While it might not directly screw up recordings, it's nice to have
>> your Cable Modem, DSL box, router, switch etc. all on the UPS as  
>> well.
> Before you connect all your stuff, make sure they really work when  
> fed from
> the UPS. E.g. the output voltage of my UPS drops considerably (by  
> design!) in
> case of a power failure. A switching power supply in a computer can  
> handle
> this but other devices may not. Once I tried to use my cord shaver  
> off the
> UPS. Not a pleasant experience... but it was an emergency ;)
> Tom

Good point. Good quality UPS units that output something even  
resembling a sine wave and can handle highly reactive loads are very  
expensive. The low-cost units sold at computer stores work in most  
cases but output a waveform that looks like it would be more at home  
on a hospital cardiac monitor.

I think most modems, switches etc. use a "wall wart" power supply,  
and transistors being cheaper than transformers, inductors and  
capacitors they are mostly switching units and should work on the  
cheap UPSes.

No substitute for testing though, and a "fire drill" test of UPS  
installations is a must.

Also, as most of us use one or more power strips, wrapping electrical  
tape around the switch to hold it in the "on" position is a good  
idea, it's awfully easy to hit those switches by accident, not to  
mention kids, pets, wives and vacuum cleaners.

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