If the smoothing is working properly, does the peak input voltage matter? Wont it smooth out to somewhere around the RMS?
That still may be much more than the device was rated for.
Indeed. I’m tempted to get hold of one of the 110V-labelled ones and open it up to see if it’s any different inside.
Me Chinese, me play joke, me put inadequate power supply in your LED light bulb.
Opium Wars NOT forgotten Limey roundeye.
Yeah, I’m caulking this up to “cheap electronics company” or some sort of knock-off of a decent brand.
Check out this article on a guy who got a VERY poor fake PSU for his camera.
Now it seems like these bulbs aren’t as bad as the PSU in the article, but it does show you that there are a lot of scummy companies out there putting out the bare bones (and sometimes not even that.)
I’m an engineer in the industry, I can confirm that these are cheap crap versions trying to maximize output with high numbers of lower cost/quality LEDs.
The technology is mature, but the manufacturers are loosely regulated and can make any ridiculous claim to sell their product. LED technology is ‘immature’ only inasmuch as television technology is ‘immature’–you get what you pay for and a fringe brand at a low price is most likely shoveling unreliable garbage that won’t perform.
In the US, the Energy Star program is the means to try and control the consumer market and benchline a minimum performance and reliability. In the US, I would never buy a home LED replacement that hadn’t been vetted through Energy Star at a minimum.
I think what’s happened here also is that the market has been so effectively flooded with these exact devices, that they’re now being resold at higher prices by retailers who people otherwise consider reasonably trustworthy - which lends an unwarranted air of quality to the cheap (yet identical) direct-from-China devices.
Is it mature though? Is there such a thing as a drop-in replacement for the kind of incandescent lamps used for main lighting fixtures in domestic rooms? With spectrum that is really comparable to other forms of lighting?
A capacitor input filter (capacitor after the rectifier) will result in an output near the peak input voltage, around 340 v for 240 vac (1.414 x RMS), if the capacitor is large enough or it is unloaded; in this case, the capacitor will mostly discharge to the LEDs minimum on voltage between peaks, so it doesn’t really do much (for fun, I tried simulating the circuit in LTSpice IV; the circuit drew over 50 watts(!) with a bridge rectifier and 4.7 uF capacitor and one of the lower power LED models provided; a 1 uF capacitor in series with one of the input lines dropped it to 5.3 w).
I see that all the time (especially omitted parts) in electronics that were tossed out and wonder why they even bother making room on the board for the omitted parts since then they could save even more money! I can also make a much better power supply than that, since I have made literally dozens (all for personal projects). Now I don’t know if they would all pass FCC testing, but noise and especially ripple is definitely a lot lower than that and low enough not to cause malfunction in circuits far more complex (including multiple DC-DC switching regulators which can make noise themselves) than a PIC microcontroller and LCD display.
I have some of these in my lamps. look close enough to incandescent to make me happy.
Another company called Switch Bulb Company has A-type bulbs like this 100-watt equivalent.
It still seems that LED emitters (even the good ones) have spectra with a big peak around 450nm (blue), another one around 550nm (yellow - the light emitted by the phosphor), but not so much in the green and red parts of the spectrum.
Which means the light may be perceived as white - and white objects illuminated by it will look bright and white - and blue or yellow objects will look more or less normal too, but (for example) a green chair, or a red carpet may look unusually dark.
Of course, neither tungsten nor fluorescent illumination are perfect either - but it seems to me that LED manufacturers are aiming for the best perceived white blend, rather than a full spectrum.
That’s one of the ugly secrets about LED lighting - there is no such thing as a white LED (a LED that emits white light by itself); as you said, they are actually blue LEDs with a phosphor that concerts some of the blue to yellow. However, there is no reason why they can’t use actual separate LEDs to make full-spectrum (or nearly so) light, such as using red, green and blue LEDs together. That would also make it easy to adjust the color temperature if each color were independently controlled (it would also seem to be more efficient since there is some conversion loss in the phosphor).
Fluorescent lights seem to typically have a greater number of peaks (albeit quite spiky narrow ones I think) - incuding a strong one in the green and another in the red.
And yet the’re only doing the same thing as white LEDs - producing strong light at the blue end of the spectrum and using phosphors to convert some of it to make a whitish-looking blend. Why can’t we make white LEDs using phosphors that have a broader range of emission peaks?
Re reselling…Agreed. That big box stores like Home Depot and Target will willingly stock the lowest quality lights is very damaging to consumer perception.
Re maturity…Absolutely drop-ins are available. They are pricey, though, and again the big box chains are picking up the lower cost/quality ones to sell in preference to the higher priced “boutique” bulbs. I have some very lovely trade show samples that kick ass and sorely wish were available at Home Depot.
This is again what Energy Star attempts to do. It doesn’t just measure raw efficiency, but also puts strict standards on color quality, size and fit, uniformity of the light (i.e. no hot spots or shadows), et al for how similar it is to an incandescent counterpart. It is a consumer confidence label that if an LED bulb claims to be an incandescent replacement, then it has to act like it.
We can but…wait for it…they’re pricey 
The ugly little secret of the LED industry is that the LEDs with the best color rendering are also the highest in demand. All LEDs in a manufacturing batch don’t come out of the ‘oven’ performing the same. They get binned and sorted into lots based on their color characteristics. These lots are then sold, usually in limited quantities to preferred volume buyers. It has turned into something very similar to a controlled diamond/gem commodities market.
The best LEDs get snatched up by TV, display, and phone manufacturers. The “little guys” in residential illumination are left with either using the leftovers that don’t have the best color quality, or having to pay a high premium for the scarce better quality LEDs. The end result is that the retail consumer is stuck with making do with the leftovers swept up from the shop floor that the others don’t want.
I don’t see the value of today’s AC powered LED’s. I absolutely love LED flashlights and their use as marker lights in cars/trucks. But the home-use bulbs get way too hot and I suspect they will not last long enough for them to justify the cost. Since my state mandated that power companies reduce consumption we were able to buy CFL’s for .26 cents apiece.
At this point the only thing I would be interested in is a 12 volt lighting system in conjunction with a small solar cell charging system.
Converting from AC to DC isn’t really a big problem in terms of total power loss; good designs can get efficiencies of 90%*, especially given the constraints on power and heat dissipation. Even DC powered LEDs need something (usually a DC/DC converter) to provide constant current to the LEDs. The big heat sink you see is for the LEDs, which still produce more heat than light, if much less than incandescents.
*In theory, a simple capacitive limiter (as in the OP’s lamps) can have near 100% efficiency, minus a slight loss from the bridge rectifier, but is unregulated and pulses the LEDs at high current, increasing power loss with a decrease in efficiency, plus has a very poor power factor, worse than a simple non-PFC SMPS (many good designs have PFC built-in).
Perhaps you could answer this:
I think the future of lighting will be LEDs (or other efficient light sources) built into things that no longer look like lamps. Perhaps decorative objects emitting light, or panels that attach to the wall or ceiling.
Do you know if this being done by anyone? If Edison heaters and CFLs are going the way of buggy whips, why buy a lamp anymore?
If the LED’s themselves are causing the heat that is even more distressing. I question the longevity of the lights at their current cost.
my thought was to wire the lights directly to 24 volt batteries to both save money and do away with the AC/DC voltage conversion but if you’re saying it’s the LED causing all the heat then I’m not gaining anything.