I recently put CFL bulbs in all my lamps, ceiling fans and light
sockets. On the ceiling fans there are dimmers. When the fan lights
are turned on at the dimmer and then turned all the way up, one fan
light stays dim for about an hour, then will start to flicker and go
to its normal brightness and does not flicker anymore. The other
ceiling fan light flickers the entire time and also makes a buzzing
noise. i had a dimmer on the kitchen light also and it would also
flicker whenever the light was on. I replaced the dimmer with a simple
off and on switch and this solved the problem. I only have the problem
where there are dimmer switches installed. Why are the lights having
The packaging of most CFLs says that they are not to be used in
conjunction with dimmers. Dimmable CFL floods (BR30 or similar
configuration) have recently come on the market (Philips is one brand
I've seen), but they are expensive.
Unless the CFL's are the newer "dimmable" types, CFL's are not
dimmable, they have to be explicitely labeled as dimmable.
And even the new dimmable ones are not truly dimmable over the entire
range of your dimmers. They only dim with maybe the top 60% of the
dimmer travel, lower levels and the results are unpredictable with
flicker, etc. I have the same issue, 80% of my wall switches are
dimmers so I have not been able to jump on the CFL bandwagon except
for closet and porch lights.
If the govt does something un-American like make incandescent bulbs
illegal, then I will stock up from foreign sources to last the
remainder of my lifetime.
Good, build us one to look at!
Remember, the power is from the AC line passing thru a two
wire dimmer which usually needs a 5 watt minimum resistive
looking load just to work. Dang current mode solid state
-- larry / dallas
I dunnno, you may be correct. This supplier says it can be a so-so thing
when using conventional pulse width varying dimmers.
But I'm reasonably sure that compatible dimmers will become available
when LED bulbs really take off.
The most reliable dimming at this point is to have an array of LED's
and make it so you can use varying portions of the array.
The delta from no light to full brightness is very short for LED's.
That makes effective dimming tricky at best.
Well, Don, I think you'll find that when you try to use a dimmer with
an LED, it's far from linear. You'll have to turn the dimmer up about
half way, and then the LED will come on, but it will not be dim, it
will start out at about half brightness. Then moving the dimmer a very
short amount (with a very steady and precise hand) you will go from
that stage to full brightness.
Try it, and you'll see.
I believe you on that, because commonly available dimmers aren't exactly
compatible with the relatively low currents drawn by LED bulbs,
particularly when you're trying to run them "dimmed down".
But, I still feel it won't take rocket scientists to design dimmers
which DO work well with LED bulbs. But then, those dimmers might not
work too well with incandescents. <G>
I remember visiting the Hammond Castle in Gloucester, Massachusetts and
seeing good sized wall mounted variacs used for light bulb dimming in
some of the rooms in that gorgeous place.
On Wed 10 Sep 2008 02:34:20p, Jeff Wisnia told us...
IIRC, either Lutron or Honeywell marketing some type of variac as a dimmer
control back in the 1950s. We had one installed in our family room to dim
all the recessing lighting. I'm sure it was a variable transformer and not
an electronic dimmer.
(Good thing I'm a guy, not a girl)
That first hyperlink in my previous post needs a period at its end.
For some reason my browser didn't pick up the period.
So if you clicked on it and Wiki said "no way Jose", and didn't give you
the "John Hayes Hammond Jr." page, try adding a period to the end of
what's in your browser's address bar.
Computers...They do what they're told to do, not what you want them to do.
Jeff Wisnia wrote:
I don't have any dimmers installed in my home, so I can't. However, if
current through an LED is varied, then the brightness varies roughly
proportionately. That much I do know - I have done that a lot.
It is much more expensive and difficult to make a high efficiency LED
lamp appear as a resistor load than otherwise, so that is why many/most
LED lamps do not dim really nicely with conventional dimmers.
However, that does not mean that either of these is untrue:
* LED lamps can be made to dim well with conventional dimmers, either
with increase in cost or a compromise in efficiency
* Dimmers can be made that dim LED lamps well
- Don Klipstein ( firstname.lastname@example.org)
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