Power Supply Guru please - need a negative 48vdc 500ma output pwrsup 2

[reelbigfish]

External - input = Standard 120vac - output = -48vdc <negative>, 500ma.

It's a three wire:
-48vdc
return
ground

The power supply for an old Telco Systems Micro-Fox fiber optic T1 extender/mutiplex burned up. These have been discontuned for some time and we are having a heck of a time finding a subsitute.

Any ideas? I was told to use a regular 48VDC power supply and reverse the polarity, Can someone explain this?

Ca someone share a vendor or connection they can refer me to?

Thanks

 

[mforrence]

-48VDC is a common power supply. For easy to find - a Valcom VP2048c would probably do the trick. The old Executone Tri-output power supply (part # 550005) had a -48VDC output. Good luck.
Mike

 

[SYQUEST]

A Tellabs 8001 24/48VDC 1 AMP power supply should do the trick, or a WESCOM/CI 8548-00 24/48VDC 1.25 AMP unit. Do some Google-ing, you would be surprised what you might find.

One of these may even be an exact fit, if the unit is rack mounted.

....JIM....