No Spam wrote:
On Sun, 31 Aug 2008 06:25:43 -0700, Andiroo wrote:

Hi All

I recently moved to the US and have brought with me a SEC 1223 Switch
Mode Power Supply (spec is below). It is not marked up that it can run
using 120V but i tried it and it seems to be putting out about 13.2V on
my meter. I have not stress tested it with a radio connected on
transmit.

Any thoughts?


Regards

Andy

SEC-1223 SEC 23A 13.8V Switch Mode Power Supply * Input 230V AC * Output
13.8V DC * Output current 23A continuous (25A peak) * Thermostatic Fan
cooled * HF & VHF filtering *

The SEC-1223 switch mode power supply offers 23A of continuous current
output and 25A peak. This is more than enough for any 100W transceiver.
Designed with RF operation in mind, it is totally noise free and utterly
stable. Lighter than an IC-706 and bout the same size, it will fit
underneath for desktop operation. It will also fit in a brief case or
flight bag.


Some of these newer supplies can auto switch between input voltage. The
nomenclature on the spec tage will say something like....

" 90~250v "

If it says that, it's a auto switching input

Most of the 90-250V are "universal", not auto switching, as there is no
switching of the primary involved for any reasonable input voltage.
They rectify the incoming voltage, and the actual switcher that creates
the output voltage runs on that DC supply. This is the reason many
single rated (240V) switchers will run on 120V, though they don't
typically provide full current output unless they have really stout
input diodes... If you've a 250V single input rated switcher, (and no
obvious jumpers inside) it would be best to keep the output drain to
half of the rated current, unless you've been inside and can verify the
input diodes can handle the current.. (DAMHIKT) [wry smile]. Any
supply with jumpering inside to switch can typically use 120V with full
output.
Good Luck
--Rick AH7H