[Elecraft] Battery Charging with DC Power Supply

[Frank Ross W4NHJ]

I believe I read somwhere that you can do a mod to Astron power supplies to 
make the float chargable.  They sell supplies that say they are for battery 
back-up, I suspect they are already modified for float charge.

Frank - W4NHJ

----- Original Message ----- 
From: "Ron D'Eau Claire" <ron at cobi.biz>
To: "'Bill Miner'" <wg6h at yahoo.com>; <Elecraft at mailman.qth.net>
Sent: Monday, June 08, 2009 10:15 AM
Subject: Re: [Elecraft] Battery Charging with DC Power Supply


> Bill - K6WLM wrote:
>
> In the case of Astron supplies it can damage parts of the DC regulator. 
> If
> there is a "Crow Bar" circuit that operates with a battery connected to 
> the
> power supply output it will ruin your day or even burn your house down.
>
> ---------------------------
>
> How can that produce damage or a fire hazard?
>
> A "crowbar" shuts off the power supply so it produces no output if too 
> much
> current is drawn from it specifically to protect the regulator.
>
> That might happen if the power supply is turned on when the battery is
> discharged enough it demands more than the crowbar current limit, but the
> crowbar is designed to avoid any dangerous or damaging operation.
>
> Typically, the supply remains *off* until the power switch is operated
> manually, off then on, so it won't keep trying to feed current into a 
> short
> circuit somewhere. I know that's how the Astrons I've used work.
>
> So, as far as I can see, the worse that could happen is you end up with a
> dead battery if you have a discharge path with the supply off.
>
>
> Ron AC7AC
>
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