Compact Fluorescent Lamps...

I have 12 CFLs in my basement on one switch, and haven't noticed any popping sound.

"Chuck Harris"

** I just bench tested a Philips brand CFL rated at 11 watts and 220-240 volts with the following results.

Current draw = 80 mA rms.

VA = 19.2.

I pk (repetitive ) = +/- 250 mA.

I transient max = +/- 17 amps.

Chuck has a case.

........ Phil

Isn't an inrush limiter like a PTC thermistor used?

WHAT! adding USD 0.0000001 a piece to the manufacturing costs. ARE YOU NUTS!!

No. ;-)

No. CFL's are super simple HF inverters. They are powered by a bridge rectifier with a capacitor input filter. They use a pair of FET's as the active elements, and a tiny little toroid transformer.

-Chuck

I am using mostly Consumer Electronics, and FEIT CFL's. And because I use them base up, they fail fairly quickly from the generated heat.

The Arcing doesn't happen all of the time, but mostly on circuits where the CFL's are fairly old (over 1 year). Since the lamps always fail with the

10uf electrolytic going open, I am wondering if the sparking is due to an excessive amount of HF showing up on the line. It is probably time for me to put some instruments on the line and see what is really going on.

-Chuck

Poogies? Such language!

I guess it depends on the lamp. Some have a short turn-on delay, which I've always assumed is due to some sort of surge controlling thermistor. The 1-second delay is a bit annoying, but could help extend the life of your light switch. Then again the switch on our garbage disposer is 20+ years old, emits a loud *poogeie* every time you turn it on or off, and is still working fine, so I wouldnt worry too much about your light switch.

This is only an issue with the crap low end switches almost universally installed by builders here. The local supply store will have these in a bin for .19 each, as well as "spec" or commercial grade switches for 1.29 each or so. Be a big spender, upgrade your switch and the problem will go away.

Some years ago I added inrush thermistors to most of my lightswitch plates to prolong the life of the filament bulbs. As soon as the local store dropped the price of CFLs to £6.50p I replaced all the filament bulbs. At this stage I used to repair any that failed, and at the same time fit an inrush thermistor in the unit. Then the store dropped the price of CFLs to £1.99p so now I just throw any that fail and buy a new one!

Most of the light switches still have thermistors - this seems to prolong the life of both the switch and the reservoir electrolytic in the CFL - I've never done any measurements to confirm it, but I've always suspected that the inrush surge is greater on a filament bulb. Try measuring the cold resistance of a filament bulb with a DMM and calculate the current and compare that to the operating current calculated from volts & watts.

I have noticed that on one switch (builder put in) have 4 lamps (400 watt OUTPUT) don't recall input wattage. WW

Oh, you mean like the "crap" Pass & Seymour legrand commercial grade "spec" switches that I used when I wired my house? (yes, I wired the whole house.)

I learned long ago that labor figures so heavily in electrical wiring, that trading quality for a small savings in parts cost is a bad deal.

It isn't the switch, it is something to do with the CFL.

-Chuck

In the plant I where I manage the elctrical department we are almost eclusively going to CFL. We have many areas completely changed and some have been operating for over 6 years now with no apparent degradation of any switches. Many of these CFLs are 26 watt units replacing 150 watt incandescent in Cl II Div II areas. The energy savings is significant after you convert a few hundred fixtures to CFL.

Significant energy savings over incandescent and better power factor vs 'core and cap' fluorescent ballasts are why the utility companies often give rebates for updating your lamps to CFL or electronic ballasts.

"Oppie"

** Not true.

The PF of CFLs is *very* poor, due to the spiky current waveform.

A standard fluoro with cap draws a near sine wave current and is close to being in phase.

" I just bench tested a Philips brand CFL rated at 11 watts and 220-240 volts with the following results. Current draw = 80 mA rms. VA = 19.2. I pk (repetitive ) = +/- 250 mA. I transient max = +/- 17 amps. "

....... Phil

I can't refute that but I did look further into energy supplier rebate programs here in NY/USA. I had originally thought that the driving force was to push for higher power factors so that the utility would have reduced current demand (for an equivalent watts). Now it seems that they are simply pushing for more efficient lighting - CFLs being a prime example.

Regards

This is an overgeneralization. Not quite a couple years ago I had reason to sit down and measure the input current voltage waveforms of various CFLs, and there was a mix of those with "spiky" current inputs as well as some with very clean, high power factors. I believe the later were new GE bulbs.

Power factor information certainly doesn't routinely make it onto the packaging, though.

Very true. In the beginning CFLs were generally quite horrible with power factor and "spikey" waveforms.

These days some CFLs are actually pretty good. Europe I believe is the area that is trying to push ALL devices using switchers to be more "friendly" to the power grid, mostly for EFI reasons I believe.

That said, I still can't find a CFL at the local home improvement store that has a power factor of better then say 0.6. And you have to really look to find the info needed to calculate the power factor, nevermind the power factor actually being ON the box (because that would of course confuse consumers, less info=better for companies...).

TTYL

ComCast, the local cable TV and an Internet service provider, recently had a campaign touting their move to faster cable modem connection speeds, "3 megs!" What they meant was "3 megabits per second," but I'd be amazed if the average consumer had a clue how many "megs" they had before and hence why "3 megs!" was better... Just wait, in a few months they'll be advertising "6 megs!," just by redefining "meg" as "mega-half-bit per second..."

I also find it highly annoying how nearly all laptops today are advertised only as "17" LCD!" and nowhere is the actual resolution given. Even Dell only lists something like "SXGA+ 17" LCD!" and you then have to dig around to find how _they_ define "SXGA+" vs. anyone else.

I've always had absolutely abysmal luck with screw-in fluorescent lamps.

The ordinary "quick-start" 8' fluorescent tubes in my office, however, have been on 24/7 for almost three years, except for when they plug in too many grinders simultaneously on my office circuit. ;-)

(they don't like doing this, because the server goes down, which displeases the PHB. ;-P )

Cheers! Rich

--
-----BEGIN GEEK CODE BLOCK-----
Version: 3.1
GAT(E P) dpu s: a++ C++@ P+ L++>+ !E W+ N++ o? K? w-- !O !M !V PS+++ 
PE Y+ PGP- t 5+++)-; X- R- tv+ b+ DI++++>+ D-? G e+$ h+ r-- z+ 
------END GEEK CODE BLOCK------