We urgently need some standards over electronics longevity, like the ones we have over power consumption.
I've gone in and returned probably a dozen such bulbs without any receipt, just saying "hey, these are your bulbs, you say 10 year warranty, this is broken and they only came to the market 5 years ago".
Of course this only works now in the early days. If the date of manufacture was printed along with the store name, it'd be problem solved forever.
> EU law also stipulates that you must give the consumer a minimum 2-year guarantee (legal guarantee) as a protection against faulty goods, or goods that don't look or work as advertised. In some countries national law may require you to provide longer guarantees.
If the package says something like "10,000 hours" and you haven't run it for that many hours and it dies in 2 years you can get it replaced by EU law
Yes, and that mean an incandescent bulb is 100% efficient: all power used is converted to light+heat. But other systems can be more than 100% efficient - they can add more heat than the power they use. Or, in the case of central heating from waste, unused heat will probably have to be pumped off anyway, so using it is energetically free.
Yes.
> What is the other source of inefficiency that makes them inefficient for this by-use?
Heat pumps are more efficient at heating than resistive elements because they take advantage of already existing environmental heat, whereas resistive heating has to generate all of the heat directly.
To increase efficiency, many cities run cogeneration plant, where the waste heat from electricity generation is piped into municipal heating system. In this scenario, the incandescent bulbs are wasteful way to heat the house, because it only uses 20-40% of the energy of the fuel, while municipal heating uses only waste energy to produce eletricity.
Hmm.
But reality was that you had the choice between dozens and dozens of brands you never heard of before, and chances were high the one you picked just sucked. Amazon reviews were worthless because most people wrote them weeks after buying, very few people would come back if they failed after a year or two, and often by that time the company might have rebranded everything so you wouldn't know anyways. Not to mention how many people apparently are unable to recognize that atrocious 100hz flicker if the company cheaped out completely.
Long story short, all my led bulbs since 2015 are osram or Philips and I haven't been disappointed since.
Really? As an anecdatum, I replaced most of the lights in our house with cheap LED globes a few years ago and so far not a single one has failed. Maybe I'm just lucky. CCFL lamps, however, have been terrible while using 3x the power.
The thing is, as bad as the waste is — I'd much rather chuck out LED bulbs than CFL/FL.
Or did it. I noticed that if you keep it on long enough after it turns off it will come back on. I think the fuse or something gets heated and it stops until it cools.
My theory is that they test them in lamps upright. I’ve noticed much higher failure rates with fixture based and inverted bulbs.
The streetlights are putting out a lot more power (and thus heat), and thus need much better thermal management, which it appears they don't actually have.
I've had 2 led failures since I went fully led 8 years ago, one went soon after purchase and looks like a manufacturing defect, so that leaves one that could potentially be heat. Most of them are no names, most recent are Phillips though.
Heat is really ungood for LED's and the drive circuits[1]. With a recessed fixture there is no place for the heat to escape.
[1] I've noticed excepting electrolytic caps electronics that doesn't get warm, basically lasts forever.
Nothing happened to incandescent bulbs or fan.
Luckily I had a power strip with surge protection on which all my expensive equipment were hooked. Power strip blew up but saved my equipments.
Edit: if you open your mobile charger you'll see 400v capacitor right after the bridge rectifier. On 220v mains this circuit needs to handle 310v but can survive upto 400v peak to peak.
But power surges can be more than 400v, and similarly the circuit in CFL or LED driver can only survive very low band of power surges.
Unless you've surge protectors in your house actively scrubbing mains dirty electricity, you'll see your LEDs will not survive long enough.
LEDs don't survive because driver quality sucks and can't deal with mains fluctuation, and LEDs are very sensitive to temperature and voltage, little change in temperate or voltage, will drastically change the current going through the LED and will burn them.
I solved the problem of continuously burning my LEDs by running low voltage DC lines and using 3 level surge protection in my house. Now, I've several mounts for LEDs with fans which keep the temperature in control.
You need serious cooling for anything over 5w led. I am using aluminium heat sink with fan and my LEDs don't die.
This is key and how all houses should be designed. All lighting circuits should be low voltage DC. This makes the individual drivers much simpler.
edit - and small, you could dot a lot of spare leds around without a problem.
He does tear downs of consumer grade led lights for (mostly for the European/UK market since that's where he's based). It's interesting seeing some the iterations that "cheap" devices go through as they are refined to the bare minimum of cost.
Edit: Sometimes LED current is actually high-current AC with a square waveform, especially with dimmable bulbs. This is fine provided it's well-regulated and protected from spikes.
LED tolerance doesn't really play into the scenario here. It's all about the driver.
As a result you generally need to wire them in series rather than in parallel so that the current can’t differentially select the LED of least resistance and cause thermal runaway. Series wiring in turn cranks up the voltage requirements necessary to drive lots of power, requiring more costly components.
Oh, forgot to mention, different color LEDs have different forward current requirements, so have fun building a good and cheap driver for 100W RGBW.
LEDs can easily be wired in parallel as long as you use resistors to balance them. If you dial in the voltage real tight you can get away with minimal losses in the resistors. If you are really fancy you can use transistors and shunts to actively balance then for even more efficiency.
The reason why series is more popular is actually because it is cheaper and(can be) more efficient. It's not uncommon for cheap led lights to just throw 40 leds in series with a dead simple "driver" (read: rectifier, smoothing caps, and a resistor)to run it right off 120V.
Similar issues can affect parallel. If one LED fails open and you don’t adjust the current, you’ll start overdriving the other LEDs and shorten their lives...potentially dramatically. You could add current sense and shut down the board or even adjust current, but then costs go up.
Typical LED strips are small serial strings of typically three lights connected in parallel. That way if something goes wrong you knly lose a few lights.
Good caps are expensive, and cheap alternatives are plentiful. Nine out of ten off the shelf LED drivers have cheap ass chinese caps in them.
You also need good overall thermal design, which means good heatsinks, which means chunks of metal, which of course are expensive.
It's entirely possible to make a driver that will outlive any LED it powers, it's just that nobody wants to pay for it.
I dunno about the shoes but Snap On isn't really great quality anymore. The Chinese have closed the gap. Fluke, Honda and to a greater extent Toyota are all steadily moving toward more disposable products.
The cheap Chinese kitchen stuff you mentioned is actually the most durable item because in order to stand up to occasional abuse without being damaged it needs to be so overbuild that it can last lifetimes. That's simply a function of the design requirements, not any particular manufacturer's attitude though.
You raise a good point though. Its very hard to evaluate a product that's supposed to last a life time, until you've had it a lifetime. So the benefits to a manufacturer are slow to accrue, but they're also slow to dispel, so there's massive temptation to cut corners and rely on that reputation, while lowering costs.
It'll be interesting to see how the EV market works out. You have a product that could last for life (with battery replacements). I suspect they'll be viewed, by the manufacturer at least, as disposable when the battery goes.
Not sure what availability is like in the US and other countries though.