What kind of light will you leave on with nobody home

That is not how power distribution works. The subs provide HV right to the residential areas. The local branch feed transformers can all adjust for differences in the HV line to attain the proper local feed voltage, but that HV reading is seldom more than a few tens of volts out of thousands.

Now, had you said something about being far away from the final LV AC transformer that feeds a residential branch, THEN the voltage at the end of a feed can be a few volts down, and out of only 240, that makes a bigger difference.

The system is designed so that the voltage drops on long HV feeds amounts to a tiny percentage of the whole. This is why at the local level, a transformer is placed at specific intervals and sized to cover the number of connections within those intervals.

The only place one would typically find a lower voltage at the outlet would be a couple thousand feet down an unfinished driveway, where the property owner did not want to pay for his own transformer.

Reply to
Long Hair
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I quoted your whole previous post, so do not accuse me for snipping your post.

How would the electrons flowing _through_ the filament, when only one of the filament contacts are connected to an external circuit (ballast or neutral) ? Remember, the other filament contact is not connected anywhere, since starter is open.

Are the electrons flying in the tube smart enough that they hit the unconnected end of the filament, then run through the filament and then into the connected pin ?

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Most likely the electron hit the ring electrode around the filament and then flow into the connected pin or at least a very short distance of the filament closest to the connected pin. The strong current (several hundred mA) hits the ring heating it up and works as a cathode the next half cycle.

Ordinary electronic tube anodes can run red hot due to the electrons hitting the anode. Running a rectifier tube with a red hot anode will increase the reverse leakage, when the hot anode emits electrons when reverse biased.

Reply to
upsidedown

-station that also supplied houses that were much further away ...

That is what I had in mind.

There have been news stores about people who got very short lives out of th e their incandescent bulbs because their supply voltage was higher than it should have been - being at the wrong end of a long feed is a plausible ex planation, but my guess is that most of them were some idiot setting up the final LV AC transformer wrong.

--
Bill Sloman, Sydney
Reply to
bill.sloman

snip

They could make a CFL that uses an external HV "getter" supply to initiate the plasma and then shut it off. That would reduce losses and prolong the CFL's life to a huge number.

It is a coil of HV wire that runs around the outside of the tube.

Reply to
Long Hair

snip

Until the one that points up at the overhead aircraft gets you some federal charges.

Remeber those little disc guns we used to shoot at each other?

I would place a simple "slot" on the side of the doorway (or top) with the gun inside, behond the slot. Very sharp or star tipped discs could then be launched at any swing angle and folks... sharp discs go right through Kevlar armor, and many other things.

So, an unsuspecting victim would not even know that he was staring death right in the face.

There are no door-to-door salesmen in Colorado. Why? Because the owner can shoot your ass as soon as you cross the perimeter of his property, much less waiting till you get to the door. Maybe that fear alone is a good security upgrade.

Still didn't help folks like Versace or John Lennon

Reply to
Long Hair

Thank you all for the comments. It seems that a few others have seen smoke so I'm not completely alone, just a bit more unlucky. No one seems to have seen an LED bulb fail violently so I guess I can feel pretty safe as I gradually replace my CFLs. Given the still-rapid pace of improvements and price dropping I'm not quite ready to just buy a bunch of LEDs now, but hey, what are the odds of another smoky CFL? :-) :-)

--
Regards, 
Carl Ijames
Reply to
Carl Ijames

I have only had two LED bulbs fail. Both were identical 25W Eqv. bulbs that were in my barn for safety lights and were on 24/7. They both died within weeks of each other. One just went out, the other one got real dim and stayed dim for a week, before I finally replaced it. But no smoke or anything.

The odds of another CFL smoking is quite high, from my experience. (But if you put a "No Smoking" sign next to it, it wont smoke.) .

Reply to
oldschool

-----------------------------

** I didn't accuse you, read what I wrote.

** The filament has only a few ohm resistance so the same potential all over, they land anywhere on it.
** The ring ( where fitted) is ISOLATED - it says so in the notes.

It only acts to reduce blackening on tube ends.

** Even though it is isolated ?

Get real.

** There is NO comparison with electron tubes which enjoy a hard vacuum.

.... Phil

Reply to
Phil Allison

Look closely at the picture to the right. There are two extensions pointing at the ring at the end of each pin. The voltage drop across this small gap is _much_ lower than the voltage drop in the long tube. This work fine, no matter which pin is connected to the external circuit. The lamp current flows from the ring over the small gap directly to the pin.

Reply to
upsidedown

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** So is very small.
** Wot UTTER BULLSHIT !!!!!!!!!!!!

** Most fluoro tubes have no such ring which only acts to reduce blackening on tube ends.

Go away fool.

.... Phil

Reply to
Phil Allison

Is door-to-door sales still a thing? Can't say I've ever encountered one knocking on my door in Massachusetts for as long as I've been old enough to have my own place (15 years or so.)

Except for girl scout cookies/high school fundraisers, maybe

Reply to
bitrex

and JW

Reply to
krw

Fortunately, the "bang" was not from the tube shattering, it was the case/base only. I didn't crack it open further to investigate, but suspect it was more than just a transistor (maybe overpressure in an electrolytic that went short across the mains?).

Never had a CFL or 4/5/6 foot tube break indoors.

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--------------------------------------+------------------------------------ 
Mike Brown: mjb[-at-]signal11.org.uk  |    http://www.signal11.org.uk
Reply to
Mike

You're going to have to change your nym to LED Ned now.

Reply to
Long Hair

I knew those old Neon sign supplies could be good for something!

Lite his ass up!

Reply to
Long Hair

Just lost one today. Smelled it downstairs. End of tube dark with some plastic deformation.

Greg

Reply to
gregz

If I had to leave a light on and wanted safety, I would be thinking of rolling my own low voltage LED light using an old style, approved mains transformer, bridge, cap and linear regulator, all conservatively rated, plus fuse and over temperature protection.

--
I look forward to the day when a chicken can cross the road without having   
its motives questioned.
Reply to
David Eather

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** Then one of these might do as well.

No inverter, 5w consumption, equals a 30W incandescent.

.... Phil

Reply to
Phil Allison

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** Then one of these might do as well.

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No inverter, 5w consumption, equals a 30W incandescent.

.... Phil

Reply to
Phil Allison

That looks good, and non flammable. Just a question on the bulb glass or plastic. Glass - fantastic! Plastic - probably OK too.

--
I look forward to the day when a chicken can cross the road without having   
its motives questioned.
Reply to
David Eather

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