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[aprssig] Kenwood KPS-15 switching Power supply in Europe?

Dave Baxter dave at emv.co.uk
Mon Oct 15 10:44:22 UTC 2007


Not so much a UL listing, (meaningless outside the USA) but for the EU
market, it would have to pass several EMC and LVD safety tests, that
sadly much US equipment designed for 110V, does not pass, and never will
without extensive re-design and alternative components used on the AC
Line side, and the construction methods changing too, in regard to
screening, decoupling, and wire routing etc..

The LVD spec's also include a Power Factor specification, I forget the
exact numbers, but I think anything that presents a load over some 75VA
to the "Mains" needs these days to have PFC implemented, and that's
another nightmare to supress to EMC standards, though implementing PFC
itself is much easier these days with dedicated controler chips
available.

It's also why modern PC's in the EU if they are fully complient with the
LVD, do not have an AC Line Pass through connector, as that can push
them over the PFC needed limit when a monitor is powered there, as all
the power will have to come from one "Outlet".

(The fact that you can plug multiple non PFC things into a single supply
in practice, sort of negates all the fuss, but...)

The "need" for PFC, was brought about by the massive proliferation of
modern TV's and PC's etc, all using "Off Line SMPS's".  The resulting AC
Line current waveform created by all the rectifier/capacitor inputs was
causing so much harmonic distortion and heating problems for the power
distribution system etc that something had to change, hence many devices
now have inbuilt active PFC as standard, there again, many things also
do not...   Passive PFC with a "swinging choke" for example can still be
found in some non EU manufactured products.

It can also make things much easier for field day generator use, if not
for the RF noise floor! 

But, it can make it very bad to run from an existing HV DC supply, such
as Bob's Prius battery, as the DC voltage will be too low.  Some work
OK, some don't.  One or two I've tried go BANG!

Take care.

73.

Dave G0WBX.



> -----Original Message-----
> From: Alan P. Biddle [mailto:APBIDDLE at UNITED.NET] 
> Sent: Friday, October 12, 2007 8:23 PM
> To: 'TAPR APRS Mailing List'
> Subject: RE: [aprssig] Kenwood KPS-15 switching Power supply 
> in Europe?
> 
> Bob,
> 
> Found in a discussion that this is actually a rebadged Samlex 
> PS.  If so
> then: "However, the instruction manual makes no mention of 
> 230. An e-mail to Samlex was answered in one day from a Vice 
> President no less! He indicated their UL listing is only good 
> for 120, so they aren't allowed to make mention of 230 in 
> their manual. He said just slide the yellow jumper loop off 2 
> posts and the supply is enabled for 230."  If it looks like 
> that, it probably is.
> 
> 73s,
> 
> Alan
> WA4SCA
> 
> 
> 
> 
> 
> 
This mail has been scanned by Palmer Cook Computer Services Limited.  www.palmercook.co.uk



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