[time-nuts] Power Back-up

[Lux, Jim (337C)]

On 8/8/09 10:45 PM, "Hal Murray" <hmurray at megapathdsl.net> wrote:

> 
> 
>> Weather projections for California this winter are WET, which implies
>> local power failures (lasting up to perhaps eight hours).
> 
>> What do time-nuts do for backup power? I have one of the TAPR TBolt
>> systems along with numerous other toys (OCXOs that should probably be
>> kept running to avoid retrace errors). Automobile batteries? UPS
>> inverter systems?
> 
> Are your OCXOs in gear that draws real power?  Do you leave that gear running
> when you aren't around?
> 
> Check the numbers.
> 
> Small UPS boxes don't have much capacity.

Not only that, but because they're designed to run for only about 20
minutes, their thermal design depends on mass as much as actual conduction
or convection.  At low load, they're not very efficient, either.  It's
cheaper to just put a bigger battery in than to use more parts in the
inverter (lead is cheap, apparently) and still meet the spec.