Date:         Tue, 19 Jun 2007 04:30:15 -0500
Reply-To:     Matt Roberds <mattroberds@COX.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Matt Roberds <mattroberds@COX.NET>
Subject:      Re: Low-voltage alarm
Comments: cc: "Mike \"Rocket J Squirrel\" Elliott" <camping.elliott@GMAIL.COM>
In-Reply-To:  <20070618224117.YNAY2131.eastrmmtai105.cox.net@eastrmimpi01.cox.net>
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> From:    "Mike \"Rocket J Squirrel\" Elliott" <camping.elliott@GMAIL.COM>
> Date:    Mon, 18 Jun 2007 11:44:19 -0700
>
> I want to find a simple low-voltage alarm to add, too. I built mine out
> of parts I found in the junk drawer here, so I'm no help. Does anyone
> know of a cheap and cheerful off-the-shelf alarm?

No.  I do have a fairly simple roll-your-own idea, though...

Your average 30 A automotive relay in the 1" black cube, once picked up,
will drop out at somewhere around 9 V.  You could use a couple of 1N4001
diodes in series with the coil to raise the drop out voltage, and use
the contacts to trigger an alarm.  Problem: the coil will draw around
0.1 A continuously, which is a bit much for what it does.  Maybe a
solid-state relay could be used in the same way with less current draw.

Matt Roberds