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.
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.
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.
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.
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.
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.
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.
Here is one review that might be useful.
The Best Compact Fluorescent Light Bulbs: PM Lab Test - Popular Mechanics
No mention of noise, tho.
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.
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.
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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.
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.
Just cobbled up a basic Wien bridge with a AD797; with bulk foil resistors and polystyrene caps, my Tektronix analyzer bottoms out at .0010% THD. The CFLs I use in my work room can interfere with measurements and good grounding was essential; more work needed there to minimize noise if this state variable oscillator I'm putting together will get down to the next zero.
I still prefer to use CFLs for the energy savings, but they still aren't reliable enough (heat kills 'em quicker). I'd pay a dollar or two extra for better quality. LED lamps aren't quite there yet in terms of light output and reasonable price.
I still prefer to use CFLs for the energy savings, but they still aren't reliable enough (heat kills 'em quicker). I'd pay a dollar or two extra for better quality. LED lamps aren't quite there yet in terms of light output and reasonable price.
" How do you tell the good ones from the cheap ones? "
Panasonic (LED or CDFL), Sharp (LED) Toshiba (LED or CFL)
dont buy supermarket or hardware store house brands - they are cheap re-branded Chinese lamps that dont meet spec (EMI or light output) and don't last long.
The Japanese brands above are serious about quality and EMI - you will get your money's worth.
Panasonic (LED or CDFL), Sharp (LED) Toshiba (LED or CFL)
dont buy supermarket or hardware store house brands - they are cheap re-branded Chinese lamps that dont meet spec (EMI or light output) and don't last long.
The Japanese brands above are serious about quality and EMI - you will get your money's worth.
I like a CFL in the work light on my bench because I can use a really bright one without burning up the fixture. But... I also keep an incandescent around to replace it whenever I'm doing sensitive measurements. I also have incandescent ceiling lights on a dimmer and have to turn those off sometimes as well. Then there's the humidifier in the other room that cranks out some pretty good RF because it runs the fan at low speed using a triac. If I want to pick up WWVB at certain hours I have to turn off the computer as well. It's a dirty world.
CH
CH
Just to point out...
It is ridiculous for anyone to suggest that the heat output of an incandescent bulb is a good thing for contributing to heat the home in winter. This is not a "free" source of heat, the waste heat is just there due to ineffciency of the bulb, the bulb is consuming more energy to make that heat than a good heating system would, and, as already pointed out, the need for the waste heat to be countered by additional AC energy use in the summer is a factor as well.
No fan of CFLs here though. I suspect that LEDs will be the best option soon enough, if the onboard supplies are switchers, audiophiles will need to address the line noise created (as a cheap switcher is going to be noisy), but this should not be too difficult with dedicated lines for audio and good AC filtration.
Maybe someone with a really good spectrum analyiser should start a thread with line noise measurements of various bulbs.
It is ridiculous for anyone to suggest that the heat output of an incandescent bulb is a good thing for contributing to heat the home in winter. This is not a "free" source of heat, the waste heat is just there due to ineffciency of the bulb, the bulb is consuming more energy to make that heat than a good heating system would, and, as already pointed out, the need for the waste heat to be countered by additional AC energy use in the summer is a factor as well.
No fan of CFLs here though. I suspect that LEDs will be the best option soon enough, if the onboard supplies are switchers, audiophiles will need to address the line noise created (as a cheap switcher is going to be noisy), but this should not be too difficult with dedicated lines for audio and good AC filtration.
Maybe someone with a really good spectrum analyiser should start a thread with line noise measurements of various bulbs.
I use a desk lamp from IKEA on my workbench. It uses one of those low-voltage, U-shaped, two-pin florescent tubes. I have not observed any problems with EMI. My HP8903A doesn't pick it up and the HP3562A (-140 dBV noise floor) doesn't pick it up either. I do, however, find the local FM radio station (92 MHz) on my 400 MHz oscilloscope. I get about 20 mVpp induced on an o'scope probe, which makes it rather hard to perform wideband noise measurements.
LEDs have come a long way. I bought a brand name (Philips I think) one a couple of years back for a reading lamp that uses a GU-10 bulb. It set me back $35. Now they're down to $15... It's not quite as nice as a GU-10 halogen as the LED lamp is more of a spotlight, but I no longer burn my fingers trying to adjust the reading lamp...
The argument that one should use incandescent bulbs to save on the heating bill in the winter is absurd. If you want heat, use a device that's efficient at turning energy into heat. If you want light, use a device that's efficient at turning energy into light.
~Tom
LEDs have come a long way. I bought a brand name (Philips I think) one a couple of years back for a reading lamp that uses a GU-10 bulb. It set me back $35. Now they're down to $15... It's not quite as nice as a GU-10 halogen as the LED lamp is more of a spotlight, but I no longer burn my fingers trying to adjust the reading lamp...
The argument that one should use incandescent bulbs to save on the heating bill in the winter is absurd. If you want heat, use a device that's efficient at turning energy into heat. If you want light, use a device that's efficient at turning energy into light.
~Tom
Thanks! I'm learning that the hard way! I bought a 12 pak of Sylvanias for my ceiling fans and bathroom fixtures a while back. One was DOA, another works, but barely, two others died in a month or two. It's not worth the postage to send them back, and I think the providers know that!
Ditch all florescent's !!!
LED's are mature. (below) is what I start my tomato's with .. it is WAY brighter than the 160w (4 - 4ft' FL tubes) system it replaced and uses a whole 14W.
NO switching PS either , just rectified mains/cap with the leds strung in series.
Brightest light in the house for $40. Some of the led's they use for lighting will "die" shorted , making repair easy (like some Christmas led strings).
OS
LED's are mature. (below) is what I start my tomato's with .. it is WAY brighter than the 160w (4 - 4ft' FL tubes) system it replaced and uses a whole 14W.
NO switching PS either , just rectified mains/cap with the leds strung in series.
Brightest light in the house for $40. Some of the led's they use for lighting will "die" shorted , making repair easy (like some Christmas led strings).
whaaaat!!! (like 100k+ @ 70%)
OS
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