Review: Bedtime Bulb E27 LED (2200K, CRI95)

I mean, how big is the blue spike in a spectrum, like this:

I like the PublicLabs kit spectrometers, highly affordable.

Thanks for the info and the comment about the violet-driven LEDs, that was news to me.

OH, WAIT, I just looked at your web page and found the answer:

Here’s an SPD on its own if that’s helpful:

Hey! I just want to know, on amazon.ca it’s $25 for your bulb and for $2 less I can buy a 6 pack of 2200K led edison light bulbs, maybe I missed something but what does your bulb do better than this 6 pack for justifying this price tag

Note: I’m genuinely not trying to be snarky with this post. Just asking you to consider a different perspective, whether you like my product or not.

Do the 6-pack 2200K bulbs have good color performance or are they just 80-ish CRI? What about flicker? Shading of the bare filaments to reduce glare? And the elimination of “shadowing” where a pattern is projected on the wall? All issues with many filament products that we’ve worked out.

Some people will care and some will not, but I can tell you that just the LEDs in our bulb cost more than many light bulbs retail for. Custom phosphors aren’t cheap. But we’ve found a niche and many thousands of customers can attest that we’ve come up with something helpful.

Also consider that it’s my full-time job to educate people about human-centric lighting. I’m able to listen to what people are saying and genuinely try to find solutions for them. If we were making a smaller per-unit profit, I wouldn’t be able to do this. (By the way, I’m not rich. It took a lot of pain, debt, and suffering to get this business to a relatively stable place)

A comment on cheap LED bulbs: obviously they are great for the consumer in many ways. But it’s very hard to innovate when your per-unit profit is a few pennies. There’s a reason the big names are spinning out their consumer lighting divisions. Corners are cut on cheap products, many times on important things like flicker and safety certifications. Not always, but buyer beware that many things are misrepresented on Amazon.

I totally get it. The title of this forum starts with “budget.” You’re focused on value, and my product probably doesn’t fit that definition for you. That’s 100% fine by me. But if there is a product that fits your needs from a company that genuinely cares (instead of a commodity operation) consider supporting them.

It looks like the measured spectrum is also in maukka’s info-graphs, at the top center.

Nice reply yeutterg, I ordered two to try it :+1:

Thanks for your support, and I’d love to hear your honest feedback. Cheers.

Greg

Just to satisfy my curiosity, I did some tests on the AC line in my house. I don’t have any expensive power quality measurements devices, but I used whatever I had on hand.

Checking my UPS logs, I can see that during the last couple of days the AC voltage has ranged from 218 to 230 volts.

First I measured the AC voltage vs. lumen output over 10 minutes. To me the voltage fluctuations don’t seem that bad (226.1V to 228.4V).

A typical constant current controlled bulb doesn’t react to these little voltage changes in any way and would look like this:

I tested the stability of the AC waveform at my house using the pass/fail function of my scope and making a mask around the waveform. I let it run for some time, but there was no sudden spikes all the while I experienced some visual fluctuations on the bulb. AC voltage ranged from 213V to 215V during this test.

And as can be seen from the scope screenshot, the waveform is quite clean. The THD of the AC line at my house is only about 2%.

And for testing the crest factor, I used a Uni-T DMM which can show the max/min values of an AC waveform in addition to the RMS value. With a perfect sinewave the ratio between those two or the crest factor should be sqrt(2) or about 1.41.

What I got was pretty much spot on (316V/226.2V=1.4).

I also turned off most SMPS power supplies and lights, but that didn’t make any difference to the behavior of the bulb.

Too often testing the tests takes more effort than doing the tests themselves. :+1:

I tell my customers (I am an A/V dealer) constantly that LEDs are THE place to invest. If you amortize the cost of a quality lamp ($25 per) over the life of the bulb (lets be super conservative and say 10 years) you’re looking at roughly $.20 per month per bulb.

I understand it’s a lot to lay out up front but you’ll be paying for cheap products (in the form of headaches and poor color rendering) for the life of the inferior product, which with LED technology is a long time.

That’s the problem with poor quality LEDs, you’re stuck with them for much longer.

I’m curious to check out a couple for our nightstand lamps.

I’d like to try using your emitter in a flashlight (right now we use amber emitters in our evening flashlights).

Would you sell the emitter on a 16mm or 20mm board for hobbyist use?

Watermanchris: 100% agree. Plus we have a 5-year warranty, so if the product does fail for whatever reason, it’s pretty easy to get a replacement out of us :slight_smile:

hank: It’s actually a filament operating around 70 V, but we unfortunately don’t sell them. We have a pretty tightly integrated supply chain. You may consider breaking open a bulb and using the filaments from there, but consider using cheaper filament bulbs first to test as they are quite delicate :slight_smile:

Greg Yeutter , Can I become your dealer?

Please send a private message here: Bedtime Bulb | Contact

Thanks!

Actually it would be the custom phosphor I’d like to get hold of.
I could dissolve it, I guess, and paint it over a blue or royal blue LED?

If you’ve patented the phosphor, what’s the patent number?

Ah I see. Patent still pending. Right now, it’s going to be difficult to pull out of the supply chain, but we will reconsider for the future.

thank you for letting me know that even with stable power in Finland, the lights have visible flicker

I hope the manufacturer fixes the problem

well… I dont mean to be snarky
however, you dont seem to have understood maukkas comments.

I suggest you re-read maukkas posts, and let us know when you have fixed your driver

clearly the problem with flicker is not limited to USA, nor to “very unstable voltage”

«It isn’t bug, it is feature» (of filament LED bulbs)

Okay, so if I’m reading all this correctly, they’re phosphor-coated filaments?

Filaments have plenty of thermal inertia that only rather drastic fluctuations should be noticeable. The driver must exhibit some pretty serious fluctuations/dropouts to visibly register. Yeah, I’d say definitely work on that.

People used to grex about “pre-flash” when flicking on moonlight/firefly mode on some lights. Having visible stutter on a lightbulb would be a pretty serious glitch.

@jon_slider It’s unclear why you think I don’t understand this discussion. I can confirm that this is a very rare issue with the US bulbs. We’ve sold 10s of thousands with mostly happy customers. Like I said, we only see visible changes in places with power that’s too noisy.

Maukka was literally the first person to test the first batch we ever shipped to Europe. It’s good to know upfront if we have a potential issue with this batch.

We will keep testing to see if it’s an isolated case or a widespread case with the European version. The prototype did not have this issue, so we are doing an investigation to see what changed from test to production.

@Lightbringer They are LED “filaments.” Similar concept to regular discrete LEDs except shaped differently, plus our custom phosphor. The stability of light output is mostly due to the driver circuit as the diodes themselves can fluctuate very rapidly to changes in input.