48V, plus or minus, usually

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48V, plus or minus, usually

Steve Jackson-5
>> It's that 50 volt 20 amp supply
>> that's a killer!

Actually, this voltage/current is very easy to come
by, and relatively low in cost.  The telephone
industry uses this voltage and at high currents.
Surplus is readily available, and often at prices less
than the per-watt cost of a 13.8V high current supply.
 KS4VA often has such supplies at his commercial
website www.valuesurplus.com ... he also sells new
1/2" Andrew hardline for 75 cents a foot!!  (That's
how I have an all-hardline feedline system installed
here.) I have no commercial interest except to see a
fellow ham with great deals do well!  ;-)





       
               
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Re: 48V, plus or minus, usually

G3VVT
 
In a message dated 08/01/05 14:45:58 GMT Standard Time, [hidden email]  
writes:

>>  It's that 50 volt 20 amp supply
>> that's a killer!

Actually,  this voltage/current is very easy to come
by, and relatively low in  cost.  The telephone
industry uses this voltage and at high currents.  



--------------------------------------------------------------------------
 
The only point to be careful of is that yes, telecoms do use 48V though  with
+ve ground.
You have to ensure that the supply is not tied to ground inside the  PSU.
 
That said there are plenty of suitable 115AC to 48V PSU (mainly  switched
mode) used with PABX systems that should be available on the surplus  market as
there has been a large turn over of the older analog telephone  switches for
the digital type.
 
Bob, G3VVT
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