[Elecraft] Pro Audio PS

[Don Wilhelm]

David,

Insensitivity to input voltage is characteristic of a switching power 
supply.  The switcher input takes power from the AC line, rectifies it 
and stores the energy in an inductor.  Then the switching circuit takes 
the inductor energy and dumps charge in a capacitor in its output to the 
desired output voltage.  Unlike a linear supply, no transformer or 
linear regulators are required.

This is greatly oversimplifying the circuits and operation of a 
switching supply, much additional design must go into it to control the 
switching circuit, component rise and fall times and output filtering.

73,
Don W3FPR

On 7/30/2019 5:41 AM, David Wilcox via Elecraft wrote:
> I also have one of these power supplies and am very happy with it.  Can someone please explain how it knows what voltage is input (120 v versus 240 v) to get the same 12 volts output.  Is there a different power cord?  Am sure it needs the correct wall plug adapter. Or is there just a 12 volt regulator in the output? Inquiring minds (my old 74 year old one at least) want to know.
>