Burn out 120V lamp on 120V circuit?

On 6/08/2010 4:03 AM, VWWall wrote in part:

The upcoming USA incandescent lamp ban scheduled to take effect in phases from 2012 to 2014 has a lot of exemptions.

Exempted ones include tubular, flame shape, globe shape, rough service, reflector flood and spot, in general ones 25 watts or less, and ones producing more than 2600 lumens (nearly all incandescent lamps 200 watts or more and some 150 watt ones), and ones with a base other than "right hand" threaded E26 or E27 medium screw.

I list these and other exemptions in:

That is very interesting (and a little disturbing). I did not realize that an outright ban on incandescent lamps was set to be implemented here in the US. Even though I am a greenie and a Sierra Club member since 1975, I really disagree with outright bans on products that may not be as efficient as other technologies. The proper way to control production and sale of something that is determined to be detrimental to the environment, health, or other item of concern to society, is to tax it appropriately and in accordance to how much damage it may cause and the cost of remedying that damage.

Incandescent lamps are not always inferior to more efficient replacements. In winter, especially if a home uses electric heat, an incandescent lamp is nearly 100% efficient if you factor in the heat as a valuable output. If you are seated next to a warm incandescent lamp you might even turn down the thermostat and allow the rest of the room to be colder, resulting in a net saving. And many CFLs do not work well in extreme cold, although they are OK down to most minimum temperatures here in MD. Also, CFLs are more hazardous if they break or are put in landfills rather than properly recycled. But LED lamps will probably soon replace most CFLs.

There are also ways to get around a ban of this type with so many exceptions. What about stringing 10 automotive 12 VDC lamps in series and mounting them on a standard Edison base?

BTW, how long do you think a CFL will remain lit after it has broken? My dog pulled a desk lamp with a CFL onto the floor and I saw that it remained lit, but a large part of the lamp had broken. By the time I pulled the plug it had probably remained lit for as long as 10 seconds. When I saw that the bulb had broken and only two short tubes of glass remained, I tried plugging it back in about 10 seconds later. It actually lit again, for a couple of seconds, before going out for good.

Paul

Again a totally corrupt government has done it for us... The problem is that there are virtually no 'safe' CFLs (most are made in china with substandard components, and represent a fire hazard), and it is difficult to safely dispose of CFLs as you can't just throw them away.

So now we're stuck with lamps that must be kept off if no one is nearby to watch them in case they fail, (so no 'keep to porch light on while you are out in the evening...'), the damage our economey, and do more damage to the environment than incandescent lamps do.

Good move, guys, why don't you just ban all electric lights. Hell, I don't mind living in the dark, after all darkness and ignorance are hand-in-hand, and ignorance is what lets you hurt us.

Ever heard of UL/CSA standards and testing? That's why we can have virtually all electronics and much electrical stuff built offshore and far fewer problems occur than during the golden age of making electronics on-shore. The US has rather weak mandatory standards on safety, so the consumer must take some responsibility (and good stores will have some fear of being held legally responsible for problems). Is there even a single case of a properly used CFL causing a fire? There are many, many cases of incandescent bulbs causing fires.

I take mine along with the long fluorescent bulbs, car batteries and left-over paint to the free local household hazardous waste transfer station. Takes me about 15 minutes once or twice a year. The long flourescents (8' and 4') are the biggest hassle. A year's worth of CFLs for a _big_ house will fit in a small tupperware type container.

Or buy a decent brand, like GE or Philips, from a decent store rather than a flea market, dollar store, or the back of a truck.

Wow.

LT's solver is happier with a couple of mods:

Change GR to 1 3 10 0 1 Add R5 3 0 1E9 (allows floating input)

Something is wrong there??? The model (as I wrote it) handles neither end needs to be at ground.

Shit happens :-) ...Jim Thompson

Terminal 2 grounded, no problem. Terminal 1 grounded, didn't work.

Changing GR to reference node zero, rather than 2, allows grounding either input. Also allows connecting several in series.

I'll double check it, I haven't used it for about 10 years.

What simulator are you using? LTspice? ...Jim Thompson

Fred,

Looks like a bug in there. Should be totally symmetrical. I'll fix it and re-post. ...Jim Thompson

Yes, I'm using LTSpice.

I actually drew an LTSpice schematic from the subcircuit to get an idea of how it worked. Interestingly, although the generated netlist is (AFAICS), identical to the subcircuit listing, LTSpice barfs, complaining about a singular matrix, and needs some R (any old value) from node 2 to ground to satisfy the solver. Just grounding node 2 doesn't work. Running the original subcircuit *as a subcircuit*, just works, with the proviso I mentioned about symmetry. I guess I might have found a "feature" in the way LTSpice parses schematic input as against subcircuits. Either that, or I can't see the wood for the trees.

I like the way you did the model. I'm looking at ways of incorporating the polynomial for R versus T, that the Intusoft model uses. AIUI, that's curve fitted from actual lab measurements on tungsten wire.

The Intusoft model (see an earlier post) derives its tau from the rated power of the lamp. I don't trust that.

A former employee of mine, at GenRad, John Spellman, took the data, and together we did the subcircuit.

We used it on an old WWII aircraft re-furb project of his about 10 years ago.

When I get a free moment :-) I'll reconstruct it. It appears there's some asymmetry relative to ground, which I'll fix, then re-post.

(Polynomials are a PITA. Maybe it could be done with a TABLE?) ...Jim Thompson

Surprising. I have see it at least a couple times in the newspaper and at least a half dozen times in the newsgroups I follow. I suspect it has appeared here as an example of the socialist-government-takeover-of-America (except the socialist that signed the bill was Bush 2). The loon from Minnesota (Michelle Bachman) tried to make it a big issue (ignoring, of course, what the ban really did).

If you look at Don's link (in addition to what he wrote above) the ban does not cover a whole lot of incandescents. And the 'banned' lamps are not banned if they meet efficiency standards. There may be some current incandescents that do.

I understand that you can apply 110VAC to the shriveled useless testicles of a tree hugger and get a substantial amount of light (and noise) for as much as TWO MINUTES... then you get smoke ;-) ...Jim Thompson

Yes, but it smells like burning rope.

Quite a bit. Possibly 5 to 10 times line voltage. Very many small to household small to medium size induction motors include starter windings and some kind of starter circuit that disconnect that winding as the motor comes up to speed. It could have quite a kick, added to by transformer like issues as the main run windings also dump into the starter winding.

Why? Is there _any_ evidence that that this is not the case?

Sure, start with motors and lamps of about the same rating in normal watts.

What is the watt ratinggs of the motor and the lamp? Capacitor start motors by definition include some kind of switch that changes when the motor is up to some approximate fraction of full speed. There are way too many variations for the starting switch to guess the operating characteristics.

You forgot to make the PC gender neutral chnages.