[Elecraft] K3-Front panel shut down question.

[Vic K2VCO]

You could connect a battery and a power supply to the K3 power input, if you put a diode 
in series with the battery and one in series with the power supply. The cathodes of the 
diodes would go toward the K3. Then as long as the voltage of the PS was greater than that 
from the battery, the power would come from the PS. If the PS went off it would come from 
the battery. The diodes would prevent any current from flowing between the PS and the battery.

Of course a UPS is an idea, but many UPS' generate a lot of radio noise. After all, they 
contain inverters, which are switching devices.

On 8/17/2011 3:12 PM, kf4clo wrote:
>   My K2 is set up with a power supply to the 100w connection and a battery to
> the low power connection,
> If commercial power cuts off without warning(and it does sometimes)the K2
> stays on with battery power.
> I am looking for a way to do this with my K3 so I can at least shut down
> from the front panel when this happens. I understand the K3 don't like it
> when shutdown other than the front panel. Maybe a battery between the power
> suppley and the K3?(or is there a better way).

-- 
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco/