On Sep 18, 2005, at 7:11 AM, Vasile Surducan wrote:

>>> Input range is 20-48 and required
>>> output is 12vdc @ 10Amps with a max of say 15-20A.

Can you tighten up that spec?  15-20A for how long?  With what
sort of behavior on the output voltage?  Otherwise, you're looking
at a 12V@20A power supply, which is twice the nominal 12V@10A...

>> A classic Linear regulator is the multi 2N3055 pass transistors feed 
>> by
>> a single 3055 driven by a 723.
>
>   20A x (48-12)V = 720W
>
Ouch! (of course.)  The nominal 240W switcher is no piece of cake 
either,
especially since the specs miss the 36-72V input range used in telco
equipment that circuit designers tend to aim for...

BillW

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