Fluorescent Dimmer - It's OK?

[fine-tune]

I have a huge collection of electronics books and old factory data books. I know everything is
online, but it's too painful to throw them in the trash. Long before ultra miniature SMD's
there were published designs for fluorescent dimmer switches. I never tried to breadboard
any of these schematics. They all looked like a disaster waiting to happen!

I really need one now, and this model at eBay looks good to me:

http://www.ebay.com/itm/Lutron-NF-10-IV ... SwoudW9zVZ

My shop is divided into a large room for "dirty work" like cutting, grinding, etc. The smaller room
is for "clean work" only. I installed a standard 48 inch fluorescent fixture on the ceiling. Normally,
I want tons of bright lighting. In my very small "clean room" those two 40 watt fluorescent bulbs
are just too glaring. I've tried the bulbs labeled "natural" or "daylight." It doesn't help. I don't
want to junk the fixture, so my only option is a dimmer.

The wiring is very simple. Just a standard single pole wall switch. If I purchase this Lutron dimmer
will there be any problems? The last thing I want is fluorescent lighting with visible flickering or
flashing.

[sghioto]

Another option is to replace the fluorescent bulbs with dimmable LED replacements. You will need to rewire the fixture and bypass the ballast. Use a dimmer suitable for LEDs.

Steve G

[fine-tune]

That is an option Steve G, but once I remove the fixture it's going to be replaced, not rewired.
The idea is to find a simple solution that works.

Modern fluorescent dimmers may be very good, but I have never used one. I guess my brain is
stuck in the past. If I remember correctly, the early attempts at dimming fluorescent lighting
were not very successful.

Before I buy this Lutron dimmer can you assure me it will operate smoothly?

[sghioto]

Before I buy this Lutron dimmer can you assure me it will operate smoothly?

No!

Steve G

[dacflyer]

i would say try it out with a variac 1st if you have one,, but a lot of rapid start ballast do not work well with dimmers of any sort.. unless the ballast is rated for dimming..
you will most likely have same issues with electronic ballast..

[CeaSaR]

Do you have a cover or diffuser on the fixture? That goes a long way toward taming the harshness. And if it is still too bright, a bit of spray on glass frosting will further mute the light.

CeaSaR

[Lenp]

All gas discharge tubes will normally have a range of dimming from full to someplace around mid brightness after the gas is ignited. When the firing voltage is too low either they will not fire, flicker, or go out. That exact point is a bit hard to judge since things like design, gas pressure and age can affect the firing. That's why fluorescent tubes used in outdoor lighting use a cold temperature ballast. It compensates by increasing the firing voltage as it gets colder.
Side note: The common neon lamp glows with both electrodes on AC, and only one on DC. If the lamp is supplied with a voltage just under the firing voltage in the dark, It will fire when illuminated! It also makes a great oscillator with just a few parts. Years ago because of their zener like firing they were used as logic elements in early calculators. Ref: ANITA Calculator

[haklesup]

Not sure about these dimmers but I tried a standard dimmer on a "Dimmable CFL" bulbs that came with some new ceiling fans. It caused the bulbs to fail after only a few months. Totally dead. I had to rewire the fixture to accept threaded base bulbs so I could put dimmable LED back in like it should have been. I'm much happier with that result.

I presently have only 4 incandescent and 2 Fluorescent fixtures left to replace. The incandescent lasted so long because the small base (candelabra) bulbs are still more expensive than I think they should be (closer to $17 each compared to less than $8 for the standard base).

I just realized I need a refresher in dimmers and motor controls

Incandescent dimmer (original type, can be used with dimmable bulbs)
Motor controller (not for brushless) (often for router speed control)
Fan controller (brushless) (usually for ceiling fan 3 speed)
Fluorescent dimmer

One clips the peak amplitude, one narrows the sine wave to a pulse but maintains peak voltage; Thyristor, Triac and FET can be used. Is anyone familiar enough to explain and encapsulate the different types in a concise way or know a link to a page that explains the types clearly.

I wouldn't bother rewiring any fluorescent tube fixture. $ for $ the complete replacement is just as good a deal. It depends on how hard it is to remove. A hanging shop light, no problem, A custom kitchen luminaire, that might be harder. The Lm/W savings from Fluorescent to LED is not quite as dramatic as moving from incandescent. For infrequently used shop lights, leave as is until they fail.

[dacflyer]

would this be a option for you ? ( dimming ballast ) less than $40.00, and uses T8 Bulbs.

https://www.1000bulbs.com/category/dimm ... -ballasts/

we use something like this in our computer room at work.. the room is filled with a bunch of tv monitors and the guys like it with less light in there... the ballast been in use over 3 yrs now and in dim mode,, and the bulbs are not even blackened yet.
might