One thinkng I forgot to mention: Batteries should be charged from a current source. What this means is the maximum charge current should be limited to protect the power supply. I would call Astron and ask them how to modify the RM35M so it starts folding back at 15A instead of its default of 35A. Your power supply will thank you for it.
Steve WA6ZFT On Sunday 26 September 2004 20:20, Steve Rodgers wrote: > The question should be how long before the Astron RS-35M burns up running > at 34A? The power supply is rated for 25A continuous duty, 35A intermittent > duty. I don't like running mine north of 15A continuous without a fan. > This is the weakness with the Astron supplies. If you load them up to rated > output they run very hot. If you are planning on running 35A continuous, > I'd get an RM-60 or an RS-70. > > Steve > WA6ZFT > > On Sunday 26 September 2004 20:01, Steve Grantham wrote: > > How long would the RS-35M run in current limit at 34 Amps? (This is > > about 97%.) > > > > I have noticed that the internal ammeter sometimes lacks good > > calibration. As measured on a quality manufactured shunt, 34 Amps pegs > > out the panel ammeter on the RS-35M, which indicates 40 Amps Max. > > > > Anyone have experience with this? > > > > Steve > > AA5SG > > > > > > ------------------------------------------------------------------------- > >-- ----- > > > > The below quoted from: > > http://www.repeater-builder.com/astron/astron-rsbattmod.html A couple of > > additional comments presented by Joe Montierth .... > > One, the 10K resistor can be 1/4 watt or even 1/8 watt, the 1/2 watt is > > overkill. There is not much voltage across it to generate any heat. > > > > Two, depending on the size battery it is attached to, you might want to > > reduce the current limit point on the Astron. The 35 amp Astron will > > current limit somewhat above the 35 amp point, maybe around 37-39 amps. > > If you have it attached to a BIG battery, it can run several hours at the > > current limit, and burn itself out. If you parallel R4 with a 1K pot, you > > can adjust the current limit to a point less than 38 amps, usually about > > 70-80% of the power supply rating is good. > > > > Three, always turn the PS "on" before attaching it to the battery. This > > will keep the internal caps charged up, so they don't have to suddenly > > charge through the pass transistors on the Astron. > > Yahoo! Groups Links > > > Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
