[rescue] Re: 48v 15 amp power supply kit?
mcguire at neurotica.com
Wed Aug 6 11:35:02 CDT 2003
On Wednesday, August 6, 2003, at 08:18 AM, Michael Thompson wrote:
> There is reason that the -48VDC telecom power supplies are expensive.
> are really rectifiers not power supplies. They are designed to be
> to the DC load and a string of lead acid batteries. The battery
> circuitry is fairly complex and varies the charging current based on
> available power and the battery's temperature. It also has a low
> disconnect relay and alarm circuits.
> Telecom equipment is designed to run at a minumum of -36VDC and a
> of -58VDC or -72VDC. If you can find an unregulated -48VDC power supply
> that doesn't have a battery charging circuit it should be inexpensive.
> a look at some of the feroresonant designs.
...which of course makes "rectifier" a gross misnomer, like pretty
much everything else in the telecom industry. There's a lot more going
on in there than simple AC/DC conversion. If it were really just a
"rectifier", its output would be something like 160VDC.
Dave McGuire "You don't have Vaseline in Canada?"
St. Petersburg, FL -Bill Bradford
More information about the rescue