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light dimmer save energy? 3

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spncusa

Structural
Jul 14, 2005
1
does anyone know how much energy light dimmers really save when you turn them down. How do they regulate the britness anyway?
 
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jraef and itsmoked

Thank you both for your tutorial on line noise.

I'll swap out the cheapo dimmer.

pennpoint
 
Personally I hate the colour of the CF light. It gives me headaches.
If I was going to have LED lighting, I'd also be checking the colour carefully. The white LEDs have a very blue colour (and doesn't that sentence sound daft, but you know what I mean) which, to my mind just isn't relaxing.
I use mostly 40W incandescent bulbs as indirect lighting, which is fine for general use. The ceiling lights are 6 X 100W which are used when we really need to look carefully at something.
I believe you can now get 2-way dimmers, which is a bit darned clever, and when I get the huge pay rise which always seems just over the horizon, I might splash out and get some of those.

(As an aside: why did they stop making 3 gang intermediate switches? My mum's really upset that I can't replace the one that she's had for umpteen years)

"I love deadlines. I love the whooshing noise they make as they go past." Douglas Adams
 
There are phosphors that mimic the colour of daylight. Table lamps are available with these bulbs, but I'm not sure if the CF (screw-in) format offers these phosphors.

Headaches are often caused by flickering.

Some white LEDs are actually UV LEDs with white phosphors, so it is actually almost the same situation as CF bulbs.

 
Actually, most white LEDs are blue chips with yellow phosphor, which explains the strange colour (red is missing).
For future applications, UV LEDs are indeed being looked into, but the technology is hardly mature at this point. With UV LEDs, it's poosible to make any colour depending on the phosphor mix (eg, pink).

Benta.
 
RobWard; Not that I can even recommend the dang things with my experience, but there are CFs that have the reddish tinge of tungsten (they call it a warm color). I have used several. (briefly) Often I would get a warm colored one and pair it with a cool(bluish) one in a ceiling fixture. That was very nice! (while it lasted) :)
 
Question somewhat related to the thread:

Does anyone know how those devices work that allow you to touch a metal part of the lamp to turn it on?


ItSmoked:

Where do you live, that you pay $0.26/kWh? Yikes!

William
 
Those touch switches work off of the added capacitance of your body to trigger a comparator

Wheels within wheels / In a spiral array
A pattern so grand / And complex
Time after time / We lose sight of the way
Our causes can't see / Their effects.

 
Sorta Back to the second original question loosely regarding the operation of light dimmers (some light dimmers, anyway); when I was a kid my dad told me the white knob controlled a variable capacitor. At the time I had no idea what the heck he was talking about, but now, I presume the variable cap was in series with the lamp and by adjusting the capacitance you adjust the impedance in series with the lamp thereby decreasing the voltage across the lamp, etc...

I vaguely remember when the knob was rotated for full light output there was a slight clicking action. I assume the clicking action was a simple mechanical switch responsible for bypassing the variable capacitor.
 
My dad has been a self taught electronics technician since he was a teenager. He was fixing transistor radios since he was 13. In fact both of my grandfathers were electronics fix-its, but nowhere near at the same level as my dad. A lot of people may not think much of him, but I have always looked up to him...and, frankly, as corny as it may sound, I always hope every cool electronics design/project I complete impresses him.

Anyway, that's just what my dad told me. I don't know if it is true that at least some incandescent lamp dimmers are made almost entirely a single variable capacitor or not, but it sure seems reasonable. And if it is true (back to the first original question loosely regarding lost power), there will be little real power loss - just a crummy power factor.
 
Um... Not to cast aspersions but I doubt any dimmers were ever capacitor droppers. The cap would have to be dang large and variable caps for power are large and clunky. Lots of light dimmers are variable resistors called rheostats. And lots of them for really big lighting loads like stages, etc. were variable transformers called variacs. But variable caps.. no!

It could be that in a dimmer switch, someone, at one time, used a variable cap to control the traic circuit inside the dimmer... but even that is cumbersome.

Perhaps the TV was up too high and you miss interpreted what your Dad was saying. :)
 
There should be some cautions made when using a triac controlled device in conjunction with some solid state voltage controlled devices. Specifically, I have seen a Basler voltage regulator for a small generator set full field when a VFD motor controller was switched on. Also, the triac current controller of a TIG welder caused the same problem. A Basler model APR 125-5 regulator will full field the generator when some triac controlled devices are used. Once you consider the damage that could occur, these noisy triac devices can be very expensive to use.
 
sdmays,
I also doubt that your Dad had it correct as an "industry standard", but if he was like my Dad and learned to make do with what you had available during WWII, he may have gutted an old radio with a variable cap tuner, and discovered that it could make a small light dim if connected right. Just a guess though.

He could also have been like my Dad and told you a whopper just to see if you would buy it, waiting for the day when you discovered his deception and had the guts to confront him with it!

For those still interested, here is a decent site explaining it all, including a brief history of dimmers.


"Our virtues and our failings are inseparable, like force and matter. When they separate, man is no more."
Nikola Tesla
 
gesh jraef why'd you get all the stars?!?

I live for stars.....
 
Well, I can't give myself stars if that's what you were implying! ;-) Someone obviously liked something I said. I live for purple stars too. My boss lets me trade them in for candy bars at the end of the month!

"Our virtues and our failings are inseparable, like force and matter. When they separate, man is no more."
Nikola Tesla

 
[pipe]

"Our virtues and our failings are inseparable, like force and matter. When they separate, man is no more."
Nikola Tesla

 
Here's an additional question. I have a torchiere lamp with a fluorescent bulb and a dimmer switch. How does the dimmer switch work? Is there a dimmer switch available for separate fluorescent lights? Ok ok. That's two questions.
 
jraef......Never let the truth get in the way of a good story!
 
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