Hacker News Reader

Comment by zahirbmirza | Hacker News Reader

The push toward LED seems to be primarily for emission target related reasons. It is very hard to buy incandescent bulbs in the UK; even for those of us that accept the cost implications. Also, many less expensive LEDs flicker at the rate of the frequency supply of the current (ie 240 or 120 Hz). This is very annoying and related to the instantaneous response of LED vs the averaging effect of the alternating current through an actual glowing hot filament. It is interesting to read on the development of blue and white LED technology.

View on HN

In the EU this was indeed done for energy efficiency/emissions. Incandescent bulbs were gradually banned from normal sale, starting with the most energy hungry (diffused 100W) and gradually expanding until only low-wattage and special-purpose bulbs were left. Special-purpose bulbs cover a large variety for everything where switching didn't make sense, like machine shops or historic buildings. LEDs aren't mandated per se, but they are the most attractive alternative. And because this all happened before brexit the UK has the same rules, unless they revised any of them post-brexit

For the most part this was a very positive step. Prices for LED bulbs plunged when they went from the "premium" energy-efficient alternative to the default option. But you also get a lot of crap on the market, and stuffing LEDs in form factors designed for incandescent bulbs makes good electrical and thermal design challenging. Even for those brands that actually try

> LEDs aren't mandated per se, but they are the most attractive alternative.

Yeah, basically what the EU did was to say: For X Watts of electricity at least X Lumen of light has to be produced. And this number was gradually increased. Since old school light bulbs are quite inefficient when it comes to producing light, they slowly had to be phased out.

> The push toward LED seems to be primarily for emission target related reasons

Is this true? I’ve got LEDs in my house because they cost vastly less to run, and because I rarely have to replace the bulbs.

Some cheap LEDs do flicker (at 50 or 60 Hz). But that’s fairly easily solved. I don’t think I’ve noticed the flicker since some cheap bulbs I bought in 2014 or so.

"I don’t think I’ve noticed the flicker…"

Well… (Sorry, let me put my tinfoil hat on.) Yeah, well that noticed part is what is worrisome to me. I do worry that there is some effect on our brains even though we might not perceive the flicker.

As an analogy, I got into those supposedly audiophile "Class D" (or "Class T") amplifiers over a decade ago. Every day I turned on the music in my office and coded with the T-amp playing. I would have told you at the time that, indeed, it sounded amazing.

Some time later I built a tube amplifier (The Darling [2], in case anyone cares—I've since built perhaps a dozen more).

When I brought it into the office and swapped it out for the T-amp, the change was sublime but immediately noticeable. I hate to fall back on audiophile terminology but it's the best I have for the experience: I was suddenly aware of "listening fatigue" that had been a component of the T-amp. I hadn't even known it had been fatiguing until I heard the tube amp in its place for days on end.

With the loss of color fidelity and the flickering issue, I'm embarrassed to say that incandescent is starting to look good to me again.

I might, as an experiment, replace only those lights that we turn on in the evening when we are relaxing, reading.

[1] https://en.wikipedia.org/wiki/Class-T_amplifier

[2] https://www.diyaudio.com/community/threads/darling-1626-amp.... and https://imgur.com/gallery/oh-darling-tube-amplifier-Lq2Sx

If the LED has good DC conversion it should not flicker at all, the flow across the diode would be constant. Just buy good LEDs, incandescent light has many drawbacks.

Incandescent light has exactly one drawback, no more.

- Less efficient - Shorter lifespan - Some of them contain harmful materials/gasses - Metal fatigue when turned on/off frequently

Probably there are more

This is a really interesting comparison, but a flawed analogy. (I’m absolutely not challenging your preference for tube amps.)

LEDs clearly do not produce anything like the spectral energy of blackbody radiation (sunlight, incandescence bulbs), and many do flicker (although that’s a byproduct of individual designs, not the technology itself). This is easy to confirm with simple sensors. So it’s completely uncontroversial to say they don’t replicate “natural” light.

Pretty much all tube amp designs produce an output that is modified from the input signal. This is what makes them sound different and to plenty of personal opinions more enjoyable to listen to music on. But they are more like the “LED” side of the lighting example - they produce an output that is different from the “natural” aka original audio material.

> Is this true? I’ve got LEDs in my house because they cost vastly less to run, and because I rarely have to replace the bulbs.

its the same thing. If it uses less electricity it both reduces the cost to you and reduces emissions from generating electricity.

I think most people would have switched over gradually anyway, but effectively banning incandescents speeded it up.

>Is this true? I’ve got LEDs in my house because they cost vastly less to run, and because I rarely have to replace the bulbs.

At least in EU is true. Citing from Wikipedia: "The 2005 Ecodesign directive covered energy-using products (EuP), which use, generate, transfer or measure energy, including consumer goods such as boilers, water heaters, computers, televisions, and industrial products such as transformers. The implementing measures focus on those products which have a high potential for reducing greenhouse gas emissions at low cost, through reduced energy demand."

https://en.wikipedia.org/wiki/Ecodesign_Directive

I have not found that LED bulbs last noticably longer than incandescents. I'm still replacing bulbs, and though I don't keep records it feels about the same.

LEDs are just terrible in every way except electrical consumption.

My first hue led is from around 2015 and is still working perfectly fine.

Every other low quality led I bought around that time or even later is long dead by now. I disagree

Even off-brand ones now are lasting longer than the ones 10 years ago. It used to be a problem, now I rarely change any bulbs.

Good LEDs in the right circumstances will last almost forever - unfortunately many LEDs on the shelf are trash. They often have small print about not using them in enclosed fixtures or sconces since their thermal management is atrocious and they will self-immolate if not in open air.

I've seen some overheat themselves even in open air!

If you buy cheap off-brands on Amazon that's what happens. The cheap ones have poor thermal management around the LED drivers, and the heat dissipated will eventually burn the drivers out, much sooner than is reasonable.

Hooray shitty capitalist incentives.

The non-cheap LED bulbs I've bought have all lasted years and years. I do have some cheap ones that are starting to fail, after just a year or so. (Problem with those is that it was really hard to find the correct bulb size and connector type, so my options were limited.)

It does seem an easy win for govts to easily conform.

I buy the ones that are suitable for dimmable switches (even tho I don't have dimmers) because there is discernible flicker with most other LED bulbs if you for eg wave your arm through the air or made a saccade. There is a certification (i think) for LED bulbs that are closer to sunlight in their emission spectrum

Look for high Ra or CRI value. Dont buy cheap LED lights, they last for far too long.

LED bulbs, even though cheaper in the long term, used to habe high enough shelf prices enough that most houdeholds wouldn’t have switched without a government push. Incandescents are literally banned now for most uses, while the economies of scale have helped drive LED prices down.

It costs 8x more to power an incandescent lamp than an equivalent LED lamp, the LED lamps pay for themselves very quickly.

It costs less to run because less energy is used; I'm pretty sure incandescent bulbs aren't emitting anything by themself! "The push" is from the government, perhaps consumer demand is "the pull".

They do emit a lot of heat!

Almost all the energy consumed by appliances in your home gets ultimately converted into heat. For example, the picture on your TV is made from emitted light rays that are absorbed by various solid objects in your home and heats them up. Same for the sounds from your speakers. Your washing machine spins water and clothes around, which makes both the water+clothes and the body of the washing machine to heat up due to friction.

A counter example is a water pump, which converts electricity into gravitational potential energy of the water as it flows upwards.

Not sure about the point of your comment. Ok, doing work generates heat. But if the primary goal is to generate light, not heat, then incandescent bulbs are terrible at their job.

which is not that bad if you want to warm your room a bit. The heat is not wasted, but added to the room. We use 250 watts to warm under the coffee tables. These are infrared-coated incandescent bulbs

What if it's a hot summer night? :)

My point was about efficiency of the generation. You want the light, you don't necessarily want the heat.

Save heating for the (efficient) heat pump.

The flickering is solely a result of cost cutting in the power supplies of these LED lights. The problem is totally solvable with a constant current switching power supply. But the filtering circuitry adds cost.

The problem is that consumers usually cannot know this about a particular light (or a lot more) at the point of purchase, so even if you are willing to pay a premium for this you cannot.

I would pay a premium for longer life, and at least in some cases (e.g. lights I read by) for better quality. How do I do so? I would love to be pointed at sources of better ones (in the UK).

In the EU, lights have to be sold with a mandatory energy efficiency label. A lesser-known component of this is that this label includes a link to a standardised datasheet, which includes things like flicker metrics, CRI, chromaticity, and a measurement of the spectrum.

It doesn't fully quantify the light, but it's good enough to distinguish trash or even passable lights from actually good ones.

tl;dr: Just buy Philips UltraEfficient (I think these are roughly equivalent to the infamous "Dubai Bulbs"[1]) or Ultra Definition bulbs. They cost a little bit more but will probably pay for themselves over the years.

Buy name brands with a history of putting out decent bulbs instead of the Amazon alphabetsoup brands that won't be around in 5 years (although TBF some of my cheap BogAo bulbs are still going strong after 8 years). You can get a good feel for the light's "quality" by looking at the CRI and color temperature.

For CRI, anything 90+ is good.

For temperature, IMO around 3000k is the sweet spot. go higher if you want sterile operating room vibes or lower if you want super yellow/orange cozy hobbit hole vibes.

[1]: https://hackaday.com/2021/01/17/leds-from-dubai-the-royal-li...

> The push toward LED seems to be primarily for emission target related reasons. It is very hard to buy incandescent bulbs in the UK; even for those of us that accept the cost implications.

Can you even buy them without buying new old stock? In the US they're banned and there's zero production.

I recall there was a guy in the EU who tried to get around the regulations by selling "heat bulbs" that were exactly the same as traditional incandescent bulbs but marketed as a heat source, but I think he was slapped down.

At least in Germany you can still fairly easily get 20W incandescent lamps. Sold as lamps for fridges and ovens, but they are available with standard sockets.

If you look around a bit you can also get 60W or 100W lamps, sold as "industrial lamps" or "extreme temperature lamps", labeled as unsuitable for household use. But those are specialty lamps that you won't find in your local supermarket. Not sure if those are new old stock or imported

Certain size/watt combos are still available for things like appliances and nightlights, but I think that includes 20W E26/A-something bulbs, and the bulbs for plug-in night lights. I can still find them on the Home Depot and some other places. No idea about quality but I still prefer how they look. There are so many other horrible energy efficiency problems with heating my home that the inefficiency of a few incandescents in key places doesn't bother me in comparison to the enjoyment I get from the nice light.

In the US they've even banned selling new old stock. I believe that was a recent change within the last few years.

If I were able to see the flicker of mains supplied LED lighting (which I cannot), then I would be very tempted to install low-voltage DC LED lighting, which presumably does not flicker.

An AC/DC power converter works the same, either built into the bulb or in a separate unit. But yes, a separate power converter is almost certainly going to do a much better job of removing the 50/60Hz voltage drop. Not sure if it would be cheaper, given the economies of scale on AC bulb manufacture. Higher quality AC bulbs may come out ahead for flicker free lighting.

It only doesn't flicker if there's no power driving circuitry - eg just LEDs and a resistor.

Otherwise, if there is a power IC present, there is flicker, though fast enough for most humans to not perceive normally (you can still check it by waving your hand in front of the light and seeing the strobed afterimage.)

That's not strictly true. The very simplest of DC LED drivers flicker, such as the classic single-transistor battery saver circuit, but a slightly more complex DC LED driver circuit will not. One of the best ways to drive an LED is with a constant current source, which typically involves putting an inductor in series with the LED and switching the supply to that at a reasonably high frequency, which would mean the LED does not flicker at all.

If it's hooked directly to AC power, isn't there by definition a flicker? With a power IC, a poorly implemented power circuit will also visibly flicker. With high enough rate and the right power characteristics it should not be noticeable. Do you notice flicker in a quality phone or monitor screen?

Yes! And this after image is distracting.

Wouldn't the supply usually be either 50hz or 60hz depending in the country?

Yes, OP incorrectly quoted voltage rather than frequency.

Reply on news.ycombinator.com