[aprssig] Charge controllers

[Demetre Valaris]

Phillip B. Pacier wrote:

> Well, speaking of charge controllers (I think we were speaking of them 
> here a few days ago), does anyone have a source for a simple charge 
> controller that I can use between an Astron P/S and a battery?  I'm 
> looking for an affordable backup power option - the West Mountain 
> Radio PwrGate is nice, but it's a bit pricey.  Many of the charge 
> controllers I'm finding on Google are of the variety for solar panel 
> charging, and are very expensive.  This is for a digipeater site that 
> is subject to power outages and needs battery backup.  The idea was to 
> have the Astron go through the charge controller to the battery, and 
> the digi hooks direct to the battery.  Thanks!
>
> 73
> Phil Pacier - AD6NH
> http://www.aprsca.net


Hi Phil and group,

Here is what I fished out of my archives. I hope it helps:

====cut here==========================
Subject: Re: aprssig digest: September 13, 2003
From: Tom Weeden <wj9h at arrl.net>
Date: Sun, 14 Sep 2003 14:42:22 -0500
X-Message-Number: 12

At 12:00 AM 9/14/03, hasan, N0AN wrote:
 >Is there a SIMPLE way to put this emergency battery supply in parallel 
with
 >the existing Astron, such that when AC mains are lost, it will 
instantaneously
 >switch to the backup battery that is being float charged. (This is one of
 >those automobile strarting portable battery setup with cig light plug, 
light,
 >etc)
 >
 >I need to have it switch automatically, and be properly isolated from the
 >Astron when power is on or comes back on. I seem to remember there is 
a trick
 >with a diode that will allow this. Could someone please clue me in, and be
 >specific!
 >
 >TIA,
 >
 >..hasan, N0AN

Yes!  April 1990 QST, page 33, had an article on modifying the Astron
supply so you could parallel it with a battery.  You have to add a 6.8-10k
resistor between pin 4 of the 723 regulator IC and the wiper of the voltage
adjustment potentiometer.  I used an 8.2k resistor, and have been running in
parallel with a deep-cycle battery with no problems for several years.

--Tom Weeden
   Amateur Radio WJ9H
   Madison, Wisconsin
   www.qsl.net/wj9h
=========cut here=========================================

Good luck.

73 de Demetre SV1UY