Nothing like spending $200 to fix a $2 problem. Go to www.mouser.com and search for L4940V12. The drop out voltage at a half amp is 0.2 volts. This means you just need to supply 12.2 volts or higher to get regulated 12.0 volts to your controller.
Dwayne Kincaid WD8OYG > > Thanks, that does sound like the unit that my friend > is using. I wasn't sure what they did to sum the > outputs, and I didn't know it had BB capability. I'd > think the voltage drop would be somewhat constant once > some load current was drawn. > > My own repeater needs at least 14.0 Volts because I'm > using a 7812 regulator in front of the controller. I > was going to buy one of the new Samlex SEC-1235M units > and push the voltage up to 14.0, but if each one drops > that much under a partial load, I think I'm going to > stay with the RS35M instead, which exhibits nearly no > drop. > > Bob M. > ====== > --- Doug Zastrow <[EMAIL PROTECTED]> wrote: > > > Bob, > > > > From the description of "five 20 A units in one box" > > it sounds identical to > > the Samlex SEC-100BRM as shown on the Samlex web > > site here: > > > > http://tinyurl.com/358l57 > > > > The manual for the SEC-100BRM can be found at the > > Samlex site here: > > > > http://tinyurl.com/3a7aa9 > > > > Page 20 of the manual shows: > > > > Two modules equpped: > > No load = 14.00 VDC > > Full load at 40 amps = 13.65 VDC > > > > Five modules equpped: > > No load = 14.00 VDC > > Full load at 100 amps = 13.35VDC > > > > > > All five modules feed a common bus. The bus is then > > fed to the load > > terminals through a Schottky diode for battery > > isolation purposes. > > > > In my personal tests with an SEC-100BRM equipped > > with two modules I saw > > no-load of 14.00 VDC. With a 7.5 amp load the > > output dropped to 13.89 VDC. > > Not nearly as heavy a load as your friend was > > seeing. > > > > My guess is the output dropping one full volt is > > suspicious. > > > > And as fair warning, I have discovered errors in > > Samlex documentation before > > so I approach their specs with a wary eye. > > > > Doug > > > > > > ----- Original Message ----- > > From: Bob M. > > To: repeater-builder@yahoogroups.com > > Sent: Sunday, October 21, 2007 4:24 PM > > Subject: [Repeater-Builder] Samlex Power Supplies > > > > > > Is anyone running a Samlex 12V supply in a situation > > where they can measure the voltage regulation from > > minimal load to something near half load? > > > > A friend has one of their 100A supplies (five 20A > > units in one box) and he's seeing about 1V drop with > > a > > 35A load (2M power amp), which is a bit more than > > I'd > > feel comfortable with. I don't know how they connect > > the supplies in parallel, so this could just be > > normal > > drop through the combining network, if any. > > > > I can't find any specs regarding this on the Samlex > > web site or in their manual for the SEC-1223. I > > would > > hope the supply can hold the voltage to well within > > 1%. > > > > For comparison, Astron RS35 supplies don't drop at > > all, or if they do, it's under 0.1V, just losses in > > the wiring. > > > > Thanks. > > > > Bob M. > > __________________________________________________ > Do You Yahoo!? > Tired of spam? Yahoo! Mail has the best spam protection around > http://mail.yahoo.com >
