[ARC5] externally generated noise from switching controllers.

[Dennis Monticelli]

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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