[TenTec] emergency back up power

[Eric F. Richards]

At 06:49 PM 3/5/2007 -0600, Dr. Gerald N. Johnson wrote:
>On Mon, 2007-03-05 at 17:21 -0500, Gary Hoffman wrote:
> > I'll bet that the battery voltage, as delivered to the actual radio, is a
> > little low.
> >
> > Going to a sine converter and 115 VAC power fixes this issue totally.
>
>At a cost of anywhere up to 50% of the battery's power from the
>inefficiency of the inverter and the linear Tentec power supply.

Most inverters today -- including a properly designed sine-wave inverter -- 
are 85% efficient and up.  The power supply is a different matter.  This is 
based on running a 500 W space heater and measuring the DC current.


>Sometimes it is more effective in the long run to let the radio struggle
>with 12 volts and to run 25 watts and to run for many hours than to run
>high power inefficiently for a few minutes. Then it helps to select the
>radio that will run from the battery that isn't being charged.
>
> >
> > Gary
>
>--
>73, Jerry, K0CQ,
>All content copyright Dr. Gerald N. Johnson, electrical engineer
>
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--
Eric F. Richards
efricha at dim.com
"The weird part is that I can feel productive even when I'm doomed."
  - Dilbert