Mains voltage transients are biggest killers of offline LED lightbulbs?

[large_ghostman]

Usually 3.3kV.
JimB

thats the one , also our house has a transformer on the pole outside, it only feeds our house,so if the transformer takes 3300V and turns it into 220V then to get a spike of 1000V you would need to put 49500V through the transformer! seems a bit when we moved in the house (29th july this year) within a couple of weeks they came and changed the transformer and i did ask if we keep old one, but they wouldnt let me have it something to do with the coolant and the value of the transformer


edit i like the idea of the generator and scope! i have a digital scope and a 10x probe

 

[JimB]

something to do with the coolant and the value of the transformer

Depending on the age, the oil inside the transformer may have been a PCB (Poly Chlorinated Biphenyl) which is nasty toxic stuff, gives you cancer and makes your bits drop off (or something like that).

Scrap metal has great value these days. Which is why you get thieving bastards stealing cables from here there and everywhere.
Sometimes they get it wrong and fry themselves.
The fluffy bunny brigade call this a tragic loss of human life.
Those of us who work to support ourselves call it karma.

JimB

 

[large_ghostman]

dont fancy bits dropping off, but would have been good to take it apart!

 

[4pyros]

dont fancy bits dropping off, but would have been good to take it apart!

Here you go;

Its mostly just a can with a transformer inside.

 

[tcmtech]

Depending on the age, the oil inside the transformer may have been a PCB (Poly Chlorinated Biphenyl) which is nasty toxic stuff, gives you cancer and makes your bits drop off (or something like that).

True but largely exaggerated. Exposure to PCB oils is rather like smoking unfiltered cigarettes. The odds are one exposure or even a number of short term exposures isn't going to do anything.

Being soaked in it for several hours a day for years on end more than likely will!

Realistically most every thing they say is cancer causing is largely based on level and time of exposure. One exposure in your lifetime doesn't mean much. continual long term exposures is what gets you!

 

[large_ghostman]

Here you go;
View attachment 82548
Its mostly just a can with a transformer inside.

i am a bit disappointed! dont know what i expected but it was more than that! still would have kept me in copper wire for a bit .

 

[4pyros]

i am a bit disappointed! dont know what i expected but it was more than that! still would have kept me in copper wire for a bit .

And that's one reason why thay would not give it to you. It may have 10 to 50 Lbs of copper in it.

 

[large_ghostman]

next time they leave it in our hedge for a week

 

[jpanhalt]

Carcinogenicity of PCB's is generally not the major toxicity concern:

Source: Wikipedia
In 2013, The International Association for Research on Cancer (IARC) determined that the evidence that PCBs cause non-Hodgkin Lymphoma* is “limited” and “not consistent.” Institutions devoted to cancer research and treatment such as the American Cancer Society and the Mayo Clinic do not list PCB exposure as a risk factor for non-Hodgkin Lymphoma.

Toxicity from PCB's generally focuses on two aspects:
1) They are quite chemically stable , are lipophilic (soluble in fat), and accumulate in the enviroment; and
2) They have neurologic, endocrine, and reproductive toxicity.

I agree that the fears are exaggerated, but that is pretty much a moot point.

John

*Non-Hodgkin lymphoma is the type of "cancer" that was thought to be associated with PCB exposure.

 

[tcmtech]

i am a bit disappointed! dont know what i expected but it was more than that! still would have kept me in copper wire for a bit .

Not necessarily. If it was made in the last 50 years the odds are it's all aluminum or copper clad aluminum windings.

Enamelled square wire for the primary and flat sheet for the secondaries.

Damn near useless for most anything else electrical or electronic.

 

[large_ghostman]

oh well i did get the isolators from the pole! no idea what they will ever be used for but they are under the bench in the might be handy one day box!

 

[ChrisP58]

Hello,
I believe that lifetime estimates for LED lightbulbs are farcical, because most of them are power factor corrected, and have very little capacitance on the primary side DC bus, and so are liable to receive component damage due to mains voltage transients.

You seem to be forgetting that, while a PFC stage will have very little capacitance in front of the PFC inductor, they will have a fair amount of bulk capacitance after the inductor and diode.

Also, any surge that does get through will just produce a very brief current spike in the LED string. So, unless the LEDs and their heat disipation are already running at the very edge of their capacity, I would expect that they could ride through a few milliseconds of whatever surge is likely to occur quite easily.

 

[Flyback]

You seem to be forgetting that, while a PFC stage will have very little capacitance in front of the PFC inductor, they will have a fair amount of bulk capacitance after the inductor and diode.

..ok, this is my bad, I didn't say what the topology was..I am not speaking of led lightbulbs with a boost pfc stage. I am speaking of led lightbulbs with a flyback pfc stage.

As the top post tells, a certain lighting company is making centralised power supplies to run multiple led bulbs, stating that mains transient protection is insufficient when done inside every bulb, that's why theyre centralising it.

 

[ghostman11]

..ok, this is my bad, I didn't say what the topology was..I am not speaking of led lightbulbs with a boost pfc stage. I am speaking of led lightbulbs with a flyback pfc stage.

As the top post tells, a certain lighting company is making centralised power supplies to run multiple led bulbs, stating that mains transient protection is insufficient when done inside every bulb, that's why theyre centralising it.

and let me guess........this certain company that is making these claims wouldnt happen to be the one you keep spamming linking to would it? Asking question's in order to get an answer is one thing, asking question's in order to promote your company and/or it's products is another, i have been in business for myself for many years now (around 30) and one little tip i can give you for free.
Marketing is a finely balanced juggling act, go to far and you risk turning people off. Alot of what you keep posting would be better done as a proper press release to relevant trade journals, then linger around and IF a question's is posted by someone that you think is answered in a release, then answer that question concisely and state your bias, then you can link to the relevant information in the JOURNAL. What at first sounded like a pretty good idea has quickly turned into something i never want to hear about again!
There maybe others who feel the same. I would have a long think about your strategy for marketing and adjust it somewhat because you are likely to do your company more harm than good at this rate.
You may have a good product (i dont know) but you are not selling it at all well

 

[alec_t]

Marketing is a finely balanced juggling act, go to far and you risk turning people off.

A very good point. I never buy anything that's heavily promoted, on principle: if it needs advertising so much then it can't be any good. Any worthwhile product/service gets recommendations from customers/users. I go by recommendation rather than by ads.

i never want to hear about again!

That sums up the obvious feelings of many forum members here.

 

[tcmtech]

i never want to hear about again!

Same feeling here.

Overselling and over promising without solid proven data to backup a claim is the #1 way to turn the people off to you that are in the very market you are targeting.

It's sort of like the "save the world/go green/environmentally friendly" hype. It's been taken so far over the top, misrepresented and misused now that it's more of a turn off than a help in marketing.

In a way it has the same effect as when a religion over sells itself or pushes its agendas on people who do not follow care for or want it. It does not bring more true followers and those forced to have to follow it start seeing every flaw and defect in the reasoning given and come to hate it that much more.

Plainly put the present info and data for the isoterra lighting systems does not add up. The potential market claims do not and can not fit the real life situations. On top of that the product itself is not yet fully developed let alone an actual item that I or anyone else can go and buy and test themselves. Plus all the weak poorly supported examples of why all other lighting systems are inferior is very clearly hand picked and not accurate as a whole.

All forms of lighting systems fail for countless reasons and so will yours too.

 

[ghostman11]

Flyback read what the others have said and take it on board, by all means Discuss lighting and the merits of one versus the other, but dont post biased questions in an attempt to talk about your product. If you thought about it you would see that actually you are missing your main opportunity, you are surrounded by people who KNOW there stuff, if i were you i would be talking about what was wrong with my product and where it falls down. Far from degrade the product you appear honest and trustworthy and even stand a chance of addressing some of your products failing's, and trust me it will have failings as the only product in my lifetime i have ever seen that didnt have any failings at all was a bottle of snake oil i purchased many years ago! funny thing is i still have most of it left

 

[4pyros]

All forms of lighting systems fail for countless reasons and so will yours too.

There will always be a weakest link.
Some times it is eazy to fix, other times it's a fundamental design flaw.
Either way it's how you deal with the weakest links that can make or brake a company.

 

[Flyback]

To be honest, I wont mention that company's name again....but just the subject area "intermediate frequency AC" lighting.
I don't have anything to do with them.
All the led drivers that I work on have the led driver inside the lamp itself.
I am genuinely interested to know if the method that involves having a centralised led driver (IFAC), is going to pop along and put myself and others like me out of business.

The thing that gets me about IFAC lighting is these questions....
1...The LED loads (as below) are obviously not resistive, and the bus current and voltage are not having a power factor of one....so how do they deal with the inefficiency that results from this?
2....How do they dim the LEDs in the IFAC system? (there is always a constant 1.9A rms in the IFAC Bus, even when they dim one or more of the lamps.
3...How do they deal with the fact that there's a one turn primary in all the couplers, and thus probably a relatively low primary inductance, and thus a high primary magnetising current?. Doesn't the magnetising current consume much of the constant 50KHz current in the IFAC bus?

Attached are schematic of general IFAC lighting situation and LTspice simulation.

 

[ghostman11]

i cant answer your question's however i for one applaud the vast improvement in your posting style! i feel you are now far more likely to get help.
As for the other system..... i dont think you need to worry about your business yet