Replies

1. 
   Clewless1 | Jan 26, 2009 01:27pm | #1

   I'm not an expert here, but I think the answer is what you don't want to hear. I think your hunch is correct: an incandescent dimmer cannot be used ... you need the special dimmer ... and yes they are expensive. Do you have a reference brand/model of CFL lamp? (I'm actually interested in that specifically). The manufacturer should give you some guidance on what device is acceptable to use with it.

   It is my general understanding that dimming fluorescent lighting is an expensive thing to be doing ... but it can be done. My guess is that GENERALLY in residential applications, it may not be 'cost effective', but that is just a semi-educated suposition on my part. There is a time/place/application for anything and I know nothing about what you are trying to achieve or what your application is, so you have to take my comments w/ a grain of salt.

2. 
   DanH | Jan 26, 2009 02:28pm | #2

   The dimmable fluorescents dim with regular incandescant dimmers. They don't dim all that well, however -- the don't dim smoothly and tend to flicker. (Though newer units are reportedly better than the ones sold several years ago.)

   The modern conservative is engaged in one of man's oldest exercises in moral philosophy; that is, the search for a superior moral justification for selfishness. -John Kenneth Galbraith
3. 
   seeyou | Jan 26, 2009 03:05pm | #3

   I'm curious if CFL's sold as "dimmable" can be dimmed with a normal incandescent dimmer

   Yes.

   Mine don't flicker as mentioned above, but the dimming is "choppy" rather than infinite.

    

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1. 
   deedlee | Jan 26, 2009 07:20pm | #4

   Thanks everyone. I'll post the model of the bulbs I want to use later. I don't have any picked out yet. The ones I bought several years ago didn't dim well, but I've heard (now from several sources) that the new ones are better. Good idea to check with the manufacturer for the specific model.Maintaining the Illusion of Consciousness Since 1969

1. 
   rasconc | Jan 26, 2009 08:31pm | #5

   Noticed some three way cfl's the other day.  Max equiv was only 100w though.For those who have fought for it Freedom has a flavor the protected will never know.

4. 
   levelone | Jan 26, 2009 11:00pm | #6

   I tried them in some can lights in my MIL apartment and ended up taking them out.  When I turned the switch on, it took a couple of seconds for the light to turn on.  The dimming would of worked okay, but I didn't think my MIL would accept the time lag.

5. 
   mackzully | Jan 26, 2009 11:13pm | #7

   If they're screw in replacement bulbs that are labeled as dimmable then you're good to go with a regular incandescent dimmer. The problem, as others have pointed out, is that the dimming is iffy. Most incandescent dimmers are simple variable resistors, newer digital ones chop the power extremely quickly to achieve the lighting level. Either of these really screw with the electronics necessary to keep the arc lit in the fluorescent bulb.

   With a true dimmable flourescent fixture, the bulb is continually kept warm while the current to the arc is varied by the ballast. The dimmer in those situations isn't doing anything other than sending a command to the ballasts over the electrical cable using a specific protocol (so that is why you'll see compatible dimmers listed for a dimmable ballast, they need to speak the same dimming protocol).

   Z

1. 
   DanH | Jan 26, 2009 11:22pm | #8

   All modern dimmers "chop" the power. A variable resistor would set fire to the wiring.
   The modern conservative is engaged in one of man's oldest exercises in moral philosophy; that is, the search for a superior moral justification for selfishness. -John Kenneth Galbraith

1. 
   mackzully | Jan 26, 2009 11:35pm | #9

   Not if they had a sufficiently large heatsink :) There were a couple of old dimmer setups in our auditorium in high school that had ENORMOUS heat sinks. Yes, I'm sure they worked, but I'd never want to be in the same room as them. But you're exactly right, all modern solid-state dimmers cycle power to dim. Z

1. 
   DanH | Jan 26, 2009 11:40pm | #10

   Yeah, I can remember a dimmer in our old church that was about two feet in diameter. Unsafe as hell too -- there was an arm that you swung around (using an insulated knob) that made contact with one of maybe 30 segments on the large dial. Everything there (except the knob) was energized.
   The modern conservative is engaged in one of man's oldest exercises in moral philosophy; that is, the search for a superior moral justification for selfishness. -John Kenneth Galbraith

1. 
   BillHartmann | Jan 26, 2009 11:44pm | #11

   I wonder if those where adjustable autotransformers.
   .
   William the Geezer, the sequel to Billy the Kid - Shoe

2. 
   DanH | Jan 26, 2009 11:53pm | #12

   May have been. It's been like 50 years since I saw the thing last. And it probably dated to the 20 or earlier.
   The modern conservative is engaged in one of man's oldest exercises in moral philosophy; that is, the search for a superior moral justification for selfishness. -John Kenneth Galbraith