Re: d-day
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Posted by Dave Houston on December 22, 2007, 7:16 am
Please log in for more thread options There's a story in this morning's NYT that, while short on specifics, implies that GE (and probably others) are working on replacements for various types of specialty lights. http://www.nytimes.com/2007/12/22/business/22light.html?ref=us And GE had earlier annpunced it would have incandescents that will meet the efficiency standard (30% increase in efficiency - which by a mysterious coincidence is what Philips new Halogena bulbs offer) by the time the law takes effect. What's not known is what the efficient incandescents will cost but, unless they cost an arm and a leg, it will make more sense to use them rather than replace fixtures. >> Of course, any reduction will affect the utilities' bottom lines so they
>> will find ways (service fees, minimum bills, etc.) to recoup their >> losses. >
>They won't have to do anything creative, just apply for a rate >hike on the grounds of maintaining their return on investment. Another factor is "power factor". I may have missed it but don't recall seeing anything that mandates a minimum PF for CFLs. If uncorrected, most have PF around 60% which means the utility has to supply 1.67x as much current as is actually used by the light. This means the green benefits are less than face value. The higher currents (and infrastructure) do constitute a real cost to the utility. So while a CFL will use less current, it's not as much of a reduction as is usually claimed. http://davehouston.net http://davehouston.org http://tech.groups.yahoo.com/group/roZetta/ roZetta-subscribe@yahoogroups.com | |||||||||||||
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Posted by Marc_F_Hult on December 22, 2007, 12:29 pm
Please log in for more thread options >Another factor is "power factor". I may have missed it but don't recall
>seeing anything that mandates a minimum PF for CFLs. If uncorrected, most >have PF around 60% which means the utility has to supply 1.67x as much >current as is actually used by the light. This means the green benefits >are less than face value. The higher currents (and infrastructure) do >constitute a real cost to the utility. So while a CFL will use less >current, it's not as much of a reduction as is usually claimed. More FUD. Dave makes up the 60% figure based on the very oldest and very worst specifications he can Google up. This is like projecting the capabilities of current and future personal computers based on the characteristics of a 1983 IBM-PC. As I pointed out nine months ago in this newsgroup in http://groups.google.com/group/comp.home.automation/browse_thread/thread/ e884c965201a543/52615a29efcdcc27?lnk=st&q=comp.home.automation+Marc_F_Hult+ cfl+powe+factor#52615a29efcdcc27 when Dave posted similar misinformation about the power factor of CFL's, the n:Vision CFL I reviewed has a _measured_ power factor of 0.94 to 0.97 -- not 0.60 as Dave now claims. This is not an exotic or unusual CFL. I bought this inexpensive n:vision CFL at the Home Depot that is a mile from Dave's apartment and measured its power factor using a Kill-A-Watt meter of the same model that Dave has written that he also owns and subsequently recommended for this purpose in this newsgroup. And as I previously pointed out in http://groups.google.com/group/comp.home.automation/browse_thread/thread/ e884c965201a543/52615a29efcdcc27?lnk=st&q=comp.home.automation++Products+ (TCP)+SpringLamp+I+introduced++earlier+the++#52615a29efcdcc27 "There are of course, higher priced CFLs with even better specifications and performance -- They just haven't reached the price point of the n:vision CFLs. .. For example, of the 20 watt (75-watt equivalent) 2700K Technical Consumer Products (TCP) SpringLamp I introduced earlier the N:Vision CFL's discussion has a rated power factor of " >.90 "
And the very technical paper that Dave Houston introduces to use as the springboard for his misinformation in the thread cited above http://www.st.com/stonline/products/literature/an/4042.pdf demonstrates that technical solutions to the erstwhile 'problem' of power factor are well known, public ally available, and have in fact been implemented my several manufacturers -- including a model whose actual performance Dave could trivially verify if he actually wanted to be constructive and accurate. ... Marc Marc_F_Hult www.ECOntrol.org | |||||||||||||
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Posted by Jeff Volp on December 23, 2007, 10:51 am
Please log in for more thread options My own observations parallel Marc's input.
Early CFLs all had large bases. I disassembled a couple over the years, and they had a rectifier feeding a large electrolytic capacitor directly at the AC power input. Some of those early CFLs attenuated X10 signals, but I never saw them radiate noise in the X10 transmission window, which extends for 1mS after each zero crossing. The early Philips "Earthlights" were totally compatible with X10 transmissions. Unfortunately, ours are finally wearing out after about a decade of service. Many have reported problems with newer CFLs causing problems for X10 transmission. I wrote a report on several that radiate noise in the X10 frequency band inside the X10 transmission window. Those have much smaller bases. While I have not yet disassembled one, it seems pretty obvious from the radiated noise that the switching converter is running over the entire waveform. That also allows them to eliminate the large high-voltage electrolytic that dictated the size of the base. To jam the circuitry into smaller and smaller bases, it is impossible to include the large high-voltage electrolytic capacitors that result in the low power factor numbers. The downside is that some of these newer units with high-frequency switching supplies radiate that switching noise back onto the powerline. Jeff > On Sat, 22 Dec 2007 12:16:38 GMT, nobody@whocares.com (Dave Houston) wrote
> >>Another factor is "power factor". I may have missed it but don't recall
>>seeing anything that mandates a minimum PF for CFLs. If uncorrected, most >>have PF around 60% which means the utility has to supply 1.67x as much >>current as is actually used by the light. This means the green benefits >>are less than face value. The higher currents (and infrastructure) do >>constitute a real cost to the utility. So while a CFL will use less >>current, it's not as much of a reduction as is usually claimed. >
> > More FUD. Dave makes up the 60% figure based on the very oldest and very > worst specifications he can Google up. This is like projecting the > capabilities of current and future personal computers based on the > characteristics of a 1983 IBM-PC. > > As I pointed out nine months ago in this newsgroup in > > http://groups.google.com/group/comp.home.automation/browse_thread/thread/ > e884c965201a543/52615a29efcdcc27?lnk=st&q=comp.home.automation+Marc_F_Hult+ > cfl+powe+factor#52615a29efcdcc27 > > when Dave posted similar misinformation about the power factor of CFL's, > the n:Vision CFL I reviewed has a _measured_ power factor of 0.94 to 0.97 > -- not 0.60 as Dave now claims. > > This is not an exotic or unusual CFL. I bought this inexpensive n:vision > CFL at the Home Depot that is a mile from Dave's apartment and measured > its > power factor using a Kill-A-Watt meter of the same model that Dave has > written that he also owns and subsequently recommended for this purpose in > this newsgroup. > > And as I previously pointed out in > > http://groups.google.com/group/comp.home.automation/browse_thread/thread/ > e884c965201a543/52615a29efcdcc27?lnk=st&q=comp.home.automation++Products+ > (TCP)+SpringLamp+I+introduced++earlier+the++#52615a29efcdcc27 > > "There are of course, higher priced CFLs with even better > specifications and performance -- They just haven't reached > the price point of the n:vision CFLs. .. For example, of the > 20 watt (75-watt equivalent) 2700K Technical Consumer Products > (TCP) SpringLamp I introduced earlier the N:Vision CFL's > discussion has a rated power factor of " >.90 " > > And the very technical paper that Dave Houston introduces to use as the > springboard for his misinformation in the thread cited above > > http://www.st.com/stonline/products/literature/an/4042.pdf > > demonstrates that technical solutions to the erstwhile 'problem' of power > factor are well known, public ally available, and have in fact been > implemented my several manufacturers -- including a model whose actual > performance Dave could trivially verify if he actually wanted to be > constructive and accurate. > > ... Marc > Marc_F_Hult > www.ECOntrol.org | |||||||||||||
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Posted by Dave Houston on December 23, 2007, 12:35 pm
Please log in for more thread options Jeff, I'm not at all sure what you're referring to or how your "large
capacitor" or X10 compatibility is pertinent to whether or not CFLs have low power factors but this is taken from the Wikipedia article on Power Factor. You can find essentially the same analysis and numbers at several other web sites having to do with SMPS design. And, people have posted Kill-A-Watt measurements of CFL PFs here that were in the 0.61 area. I doubt that low cost commodity producers of CFLs are going to voluntarily increase cost by using active PF correction. If you read my original post on this, I said "if uncorrected", most CFLs with will have low PF - what was unstated is that most CFLs now use SMPS and will need PF correction - I did not say that all CFLs must have low PF. http://en.wikipedia.org/wiki/Power_factor <quote>
In circuits having only sinusoidal currents and voltages, the power factor
effect arises only from the difference in phase between the current and voltage. This is narrowly known as "displacement power factor". The concept can be generalized to a total, distortion, or true power factor where the apparent power includes all harmonic components. This is of importance in practical power systems which contain non-linear loads such as rectifiers, some forms of electric lighting, electric arc furnaces, welding equipment, switched-mode power supplies and other devices. A particularly important example is the millions of personal computers that typically incorporate switched-mode power supplies (SMPS) with rated output power ranging from 250 W to 750 W. Historically, these very-low-cost power supplies incorporated a simple full-wave rectifier that conducted only when the mains instantaneous voltage exceeded the voltage on the input capacitors. This leads to very high ratios of peak-to-average input current, which also lead to a low distortion power factor and potentially serious phase and neutral loading concerns. Regulatory agencies such as the EU have set harmonic limits as a method of improving power factor. Declining component cost has hastened acceptance and implementation of two different methods. Normally, this is done by either adding a series inductor (so-called passive PFC) or the addition of a boost converter that forces a sinusoidal input (so-called active PFC). For example, SMPS with passive PFC can achieve power factor of about 0.7-0.75, SMPS with active PFC, up to 0.99, while SMPS without any power factor correction has a power factor of only about 0.55-0.65. To comply with current EU standard EN61000-3-2, all switched-mode power supplies with output power more than 75 W must include passive PFC, at least. A typical multimeter will give incorrect results when attempting to measure the AC current drawn by a non-sinusoidal load and then calculate the power factor. A true RMS multimeter must be used to measure the actual RMS currents and voltages (and therefore apparent power). To measure the real power or reactive power, a wattmeter designed to properly work with non-sinusoidal currents must be used. </quote>
>My own observations parallel Marc's input.
> >Early CFLs all had large bases. I disassembled a couple over the years, and >they had a rectifier feeding a large electrolytic capacitor directly at the >AC power input. Some of those early CFLs attenuated X10 signals, but I >never saw them radiate noise in the X10 transmission window, which extends >for 1mS after each zero crossing. The early Philips "Earthlights" were >totally compatible with X10 transmissions. Unfortunately, ours are finally >wearing out after about a decade of service. > >Many have reported problems with newer CFLs causing problems for X10 >transmission. I wrote a report on several that radiate noise in the X10 >frequency band inside the X10 transmission window. Those have much smaller >bases. While I have not yet disassembled one, it seems pretty obvious from >the radiated noise that the switching converter is running over the entire >waveform. That also allows them to eliminate the large high-voltage >electrolytic that dictated the size of the base. > >To jam the circuitry into smaller and smaller bases, it is impossible to >include the large high-voltage electrolytic capacitors that result in the >low power factor numbers. The downside is that some of these newer units >with high-frequency switching supplies radiate that switching noise back >onto the powerline. > >Jeff http://davehouston.net http://davehouston.org http://tech.groups.yahoo.com/group/roZetta/ roZetta-subscribe@yahoogroups.com | |||||||||||||
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Posted by Jeff Volp on December 23, 2007, 5:37 pm
Please log in for more thread options There are many fixtures that would not accept the older CFLs without some
modification. You may remember the hoop extenders that were included with some of the early CFLs. Most of today's commodity CFLs are physically much smaller with bases similar in size to equivalent incandescent bulbs. Low power factor results from a capacitor-input power supply that is only drawing current near the peak of the waveform (which also happens to be away from where X10 signals are transmitted). The small bases used in today's CFLs make it impossible to squeeze in the 175V+ electrolytic capacitor required for direct line rectification. So these newer units use a switching pre-regulator on the raw rectified AC input. That pre-regulator runs essentially over the entire waveform, resulting in a much higher power factor (and also noise radiated in the X10 transmission window). I'm amazed how cheap semiconductors have become. It may very well be cheaper to use a switching pre-regulator than the large high-voltage electrolytic capacitor needed for direct line rectification. The XTB filter capacitor costs almost twice as much as the high power MOSFET used in the transmitter output stage. It wouldn't surprise me that the pre-regulator design actually costs less. And the smaller physical size means a larger potential market for these commodity CFLs. Jeff > Jeff, I'm not at all sure what you're referring to or how your "large
> capacitor" or X10 compatibility is pertinent to whether or not CFLs have > low > power factors but this is taken from the Wikipedia article on Power > Factor. > You can find essentially the same analysis and numbers at several other > web > sites having to do with SMPS design. And, people have posted Kill-A-Watt > measurements of CFL PFs here that were in the 0.61 area. I doubt that low > cost commodity producers of CFLs are going to voluntarily increase cost by > using active PF correction. If you read my original post on this, I said > "if > uncorrected", most CFLs with will have low PF - what was unstated is that > most CFLs now use SMPS and will need PF correction - I did not say that > all > CFLs must have low PF. (other stuff snipped) | |||||||||||||
>included in the ban, it'll probably cost $5K to $8K to replace
>fixtures in the house I'm occupying.