[Elecraft] Battery Charging with DC Power Supply

[David Pratt]

In a recent message, Doug Faunt N6TQS +1-510-655-8604 <faunt at panix.com> 
wrote ...
>
>There was an article in QST a good while back about this.  Theer were
>two things that needed to be done, one of which was a fuse between the
>battery and the power supply so if the crowbar triggered, the PS
>wouldn't burn up, and the other was a resistor added so the 723
>regulator would be protected against the reverse voltage condition
>when the AC power side is off.

The KBT2 option for the K2 is designed for the SLA battery to be charged 
continuously while the K2 is run from an external 13.8V power supply. A 
Shottky diode in parallel with a resistor is in series with the battery.
http://www.elecraft.com/manual/KBT2_manual_.pdf

My K2 has been run for many years under this condition and there is 
plenty life still in the battery.  If the power is removed, the K2 keeps 
on running.

73
-- 
David G4DMP
Leeds, England, UK
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