[ARC5] externally generated noise from switching controllers.

[J. Forster]

Soapbox Mode On:

IMO, the spread spectrum switchers are EVIL. They are, philosophically,
equal to "Dilution is the solution to pollution" in the chem engineering
business. They are a way of evading the law and getting away with it. What
you wind up with is a raised noise floor everywhere.

Soap Box Mode Off.

-John

=============



> My company is a leading maker of LED drivers.  The switching style
> controllers have to pass FCC Part 15 just like everything else.  The bad
> news is that passing does not insure RFI low enough to satisfy hams or
> other
> so-called "weak signal" spectrum users.  Part 15 did not contemplate such
> ubiquitous use of "unintentional radiators" when it was first drafted.
> The
> good news is that some manufacturers are trying to get below FCC limits by
> using sophisticated spread spectrum techniques which are less onerous to
> narrow band users like ourselves.  But overall, it is kind of a losing
> battle we hams wage as switch mode controllers of all types invade our
> homes
> and offices in the form of lighting, HVAC, solar arrays, and flat screen
> TV's to mention just a few.
>
> Dennis AE6C
>
> On Tue, Jun 8, 2010 at 9:03 PM, Brian Clarke
> <brianclarke01 at optusnet.com.au>wrote:
>
>> OK, Les,
>>
>> It's just that this email stream started off with concern about the
>> amount
>> of RFI generated by household lamp dimmers, not that generated by the
>> new
>> CF
>> lamps. That's why my question about dimming LEDs. My lad wants to dim
>> LEDs,
>> too, and I have told him the dynamic range is very small - perhaps 3:1
>> at
>> most.
>>
>> 73 de Brian, VK2GCE.
>>
>> Les said:
>>
>> > Hi Brian,
>> > These lights are on or off.  There is no control over intensity -
>> except
>> > by changing the series resistor.  If I was going to control the
>> intensity
>> > I would do a very nasty thing.  I would connect an X2 rated cap (or
>> series
>> > of X2 rated caps) in series with the primary of the power transformer.
>> > (Or alternately a big fat inductor).>
>> > Les
>> >
>> >
>> In response to Brian's:
>> >>
>> >> What dynamic dimming range do you get with these LEDs?
>>
>>
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