Compact flourescent bulbs and measurements?

[alangps]

My distorsion meter started recently giving me erratic readings(some outputs of about 50kHz), I thought that it's the age of the instrument; I started exploring schematics to find a possible cause, when suddenly I had an idea.
Recently I installed a few of those bulbs around my working area, and as soon as I unplugged them things went back to normal! Of course I tried powering them up and sure enough they do radiate something that gets picked up somewhere in the lines and there you go - the bad readings were back.
I wonder if anyone had the same or similar problems with measurements and if there is any suggestion here what to do?
I could use regular bulbs but it gets hot with the lights, I kinda like those that they don't get hot, anyway any comments would be appreciated.

[zigzagflux]

CFL are just plain evil, no two ways about it. Toss out EMI, throw hash and harmonics back into the power system, and give off some uggggly light spectrum. No simple way to remove their effects while you want to make sensitive measurements. LED, when it comes to maturity, will be a welcome improvement.

Sad that the environmentalists lobbied to ban incandescents. Depending on your point of view (mine is power engineering) I consider incandescent 'greener' than CFL. Efficiency is not the only measure of 'green'.

It was environmentalists that gave us plastic bags in the late 70's. 'Save the trees' was the motto of the day. My friend recently moved to Seattle, and he laughs- they give him dirty looks at the grocery store when he uses plastic instead of paper.

Rant off.

[Pano]

I have found stray EMI from compact fluorescents, for sure. I use it as a test.

As for the quality of light, one need only the good ones. The cheap ones do look bad.

[ArtG]

How do you tell the good ones from the cheap ones?

[atmasphere]

I've been using LED bulbs made by Toshiba, available from Menard's. They consume about 8 watts. They have two colors- IMO you want to avoid the one that has the whiter color; its harder to see with. The yellow light version is really nice!!

It lasts about 40,000 hours- four times longer than a CF, although IME CFs often have failures long before the claimed 10,000 hours.

At this point I will never buy a CF again.

[Pano]

Art, there are reviews of CFLs around the web. I've had good luck with Philips.
Here is one review that might be useful.

The Best Compact Fluorescent Light Bulbs: PM Lab Test - Popular Mechanics

No mention of noise, tho.

[benb]

Don't LED lights also use some sort of switching supply? The days of the electrically quiet (except for a little thermal noise) incandescent light may be over. Anyone else stockpiling?

[alangps]

An update on the bulbs problem: for test took oscilloscope probe and put it close to bulb - got a signal on oscilloscope of 1 Vpp and about 50 kHz . Tried few of those and all of them were giving similar value of voltage which is IMO way too much.

[Johnny2Bad]

And then there's the 2009 study by BC Hydro (the electricity utility in British Columbia, Canada) that showed the ban on 75W + higher incandescents (enacted Jan 1 2011) will reduce the electricity consumption by 600 Gigawatt Hours due to lighting efficiency and reduced need for air conditioning, but increase the Carbon Emissions in that province by 45,000 tonnes per year due to the need to replace the lost heat during the winter months.

They also found that cost savings will still accrue to the homeowner with natural gas heat but the switch will probably result in a net annual increase if the home is heated with fuel oil.

BC has a relatively mild winter climate, with 90% of residents living in areas warmer than many parts of the US during winter and with no months showing an average nightime low temperature below freezing (USDA Zone 8, average coldest month (January + December identical) high/low temps of +6 /+1 C or +42.8 / +33.6F). The coldest month on record in the heavily populated lower mainland was January 1950 with average low of -9.7C / +15F and average monthly high of -2.9C / +27F.

CFLs also emit high amounts of UV radiation in comparison to incandescents. BC's Health Protection Agency found 9 of 53 samples produced UV beyond the safe limits set by Health Canada. Conventional fluorescents have a UV shield but CFLs do not. Health Canada states that there are no peer-reviewed studies available on the UV-related health impacts of CFL bulbs, so the bulbs were mandated while the health implications are unknown.

LED bulbs are becoming somewhat less expensive and somewhat more useful with regard to light output but they still have a way to go. One caveat about LEDs is the life ratings are not comparable to incandescents; the light output falls more-or-less continuously over the rated useful life. With an LED bulb they are rated based on maintaining at least 70% of light output in lumens.

[corkpuller]

I find the discussion of Pro and Con's of CFL's very interesting.

I certainly agree that the electrical vagaries of CFL's are counterproductive to the ambitions of audiophiles. However, after replacing my Class D amp with a Class A amp I sleep better at night knowing I save energy where I can.

I'd also like to point out that much of the world uses more energy keeping cool rather than keeping warm. For this percent of the population inefficient light bulbs are simply wasteful. Further, heating systems are become more efficient. I don't know for sure, but I highly doubt there have been many technological breakthroughs in incandescent lighting.