On 7 Mar 2002 at 17:00, Michel Samson wrote: >Hi Anthony, > >AJA> Does anyone out there have a BocaModem model M1440E external modem? >AJA> ...there's no wall cube to provide power. ...no specification... >DB> If you havta guess, it's prolly 12vdc; I've seen a few 9vdc. The >DB> thing is to figure out which is ground. You might see a diode... > > I have no Boca but i had four external MoDems and none of them used >D.C. power. It seems quite possible you can find no polarity because it >doesn't have any. As you may know, an RS-232 serial-port interface will >call for a bipolar +/- 12 Volts internal power supply and achieving that >with an A.C. power input is easy (cheap)... Charge pumps weren't always >popular and being a 14K4 bps, chances are it will need an A.C. supply... <SNIP>
Well, I'd hoped that someone on this list would have one, and could tell me directly, before having to go through a circuit-level analysis... I've looked at the modem a bit more, now, and it does appear that it needs an AC adaptor. There is a four-diode rectifier setup, though it's not on the circuit board where I would have expected to find it. I'll have to see what I have for AC wall power supplies - hopefully I've got something I can use. I'm planning to start with a 9VAC supply, and perhaps try a 12VAC supply if that doesn't work. Anthony J. Albert =========================================================== Anthony J. Albert [EMAIL PROTECTED] Systems and Software Support Specialist Postmaster Computer Services - University of Maine, Presque Isle "Ta'Lon, is that you?" "It's me most days, except for those days when I don't feel quite like myself and I suppose that I am someone else, but for now, yes, it is me." -G'Kar and Ta'Lon, Babylon 5 episode: _The_Ragged_Edge_ To unsubscribe from SURVPC send a message to [EMAIL PROTECTED] with unsubscribe SURVPC in the body of the message. Also, trim this footer from any quoted replies. More info can be found at; http://www.softcon.com/archives/SURVPC.html
