Linux-Hams archive - May 1998: RE: Watchdog

RE: Watchdog

Patrick Ouellette (vhmszvfk.ozshfg@multico.ru)
Wed, 6 May 1998 12:16:02 -0400


I've thought of a similar setup. Diodes to handle the current can
be hard to find/expensive, so I thought of using a spdt relay with
the coil connected to the AC that would connect the battery when
the ac drops out. The advantage I see here is the circuit that
connects the batteries uses no power and has no voltage drop
while you are on batteries.

I have been working on a similar system to keep my rig powered when
I loose AC. I use the relay to connect the battery to the charger
while the AC is on (actually while my 12v power supply is on since the
relays I am using have 12v DC coils), and to the rig when the AC drops.
The radio doesn't seem to mind the momentary power glitch when the
relay drops.

Pat

> -----Original Message-----
> From: terhi.victor@logonet.com
> [mailto:ygecoufw@f-tech.net]On Behalf Of Joe Martine
> Sent: Tuesday, May 05, 1998 10:09 PM
> To: terhi.victor@logonet.com
> Subject: Re: Watchdog
>
>
> I've been following this thread closely, having basically adopted both the
> UPS and big-battery options for my home station. The UPS keeps the Linux
> machine alive thru power bumps, and there is a big marine battery that
> keeps the radios and such going for much longer. Obviously a bit of a
> disparity!
>
> I'm wondering if anyone has taken a look at using a standard UPS - as an
> example, I have an APC Back-UPS 420 - and just run wires out to a much
> larger battery. I wouldn't think this would cause a problem for the UPS
> when _using_ the battery, it just runs longer than is otherwise possible,
> with no extra capacity. The only problem I see is the charging circuit,
> it might not like having to charge a much larger battery. In that case,
> I had thought about isolating the battery from the UPS (say, with a heavy
> diode of some sort), keeping it charged thru other means. Of course I
> then wind up with basically buying an inverter and a relay that drops out
> when the power goes away.
>
> I haven't tried this yet, but do intend to one of these days. Has anyone
> else thought about or tried it? The main reason I haven't done anything
> yet is that blasted warranty they give me...! :-)
>
> Enjoying the conversation!
>
> Joe Martine, N5USR
> aut@machlink.com
>
>
>