Is the circuit in the -BB version a charger or is it simply just a switch? Thanks, Mike
On Mon, Dec 7, 2009 at 2:39 PM, Jim Cicirello <ka2...@gmail.com> wrote: > > > Hi Eric, > > I have been trying to follow these posts on battery back power. Under this > arrangement you describe, will the supply *not* get hot with the Schottky > Diode in place if the battery is discharged very low? > > I am researching the best way to hook the battery to my Astron which does > not have the back-up charger. > > Thanks for all of the information. > > > > 73 JIM KA2AJH > > *From:* Repeater-Builder@yahoogroups.com [mailto: > repeater-buil...@yahoogroups.com] *On Behalf Of *Mike Lyon > *Sent:* Monday, December 07, 2009 12:45 PM > > *To:* Repeater-Builder@yahoogroups.com > *Subject:* Re: [Repeater-Builder] Astron RM-35M AGM charging abilities? > > > > > > Sorry. Yes, it's a -BB version. > > -Mike > > On Mon, Dec 7, 2009 at 9:31 AM, Eric Lemmon <wb6...@verizon.net> wrote: > > > > Mike, > > I thought that only the RM-35M-BB has a battery backup circuit built-in; I > have an RM-35M power supply in service, and it does not have a battery > charging circuit. > > A very simple method of achieving no-break battery backup is to install a > Schottky power diode on the positive output terminal of the power supply, > and connect both the battery positive terminal and the radio power leads to > the cathode lug of the diode. My preferred Schottky diode for this > application is an International Rectifier 122NQ030R. The diode is mounted > on a 1" wide copper bar that is placed on the power supply's positive > output > stud. The diode has a 1/4" output terminal, which makes it very easy to add > to an existing system. Note that the "R" in the diode part number means > that it is reverse polarity. The output voltage setting of the power supply > must be increased about 1/2 volt to compensate for the forward voltage drop > of the Schottky diode. The voltage should be set so that the AGM battery > has the recommended float voltage at its terminals while the radios are > operating and the system has stabilized at least 24 hours. This voltage > will usually be around 14.2-14.5 VDC, depending upon the battery > specifications. > > 73, Eric Lemmon WB6FLY > > > > > -----Original Message----- > From: Repeater-Builder@yahoogroups.com<Repeater-Builder%40yahoogroups.com> > [mailto:Repeater-Builder@yahoogroups.com<Repeater-Builder%40yahoogroups.com>] > On Behalf Of Mike Lyon > Sent: Sunday, December 06, 2009 10:02 PM > To: Repeater-Builder@yahoogroups.com <Repeater-Builder%40yahoogroups.com> > Subject: [Repeater-Builder] Astron RM-35M AGM charging abilities? > > Howdy Folks, > > I am wondering if anyone has experience with the Astron RM-35M and its > built-in charging circuit? Has anyone used it to charge 12VDC AGM > batteries? > I have 3 motorola Maxtracs (2 RX, 1 TX) that are powered from this power > supply and I need to put some backup power on the system. > > I am wondering, should I buy a separate charger for the AGM batteries (Qty. > 2) or is the charging circuit within the the RM-35M sufficient? > > 73's, > Mike Lyon > KE6MRE > > > > >
