The majority of the applied sciences and merchandise based mostly on them that I encounter in my on a regular basis interplay with the patron electronics business are evolutionary (and barely so in some circumstances) versus revolutionary in nature. A laptop computer pc, a pill, or a smartphone would possibly get a periodic CPU-upgrade transplant, for instance, enabling it to finish duties a bit quicker and/or a bit extra energy-efficiently than earlier than. However the process listing is basically the identical as was the case with the prior product technology…and the technology earlier than that…and…to not point out that the generational-cadence bodily look additionally often stays basically the identical.

Such cadence commonality can be the case with many LED mild bulbs I’ve taken aside lately, in no small half as a result of they’re supposed to visually mimic incandescent precursors. However SANSI has taken a extra revolutionary tack, within the course of tackling a problem—warmth–with which I’ve repeatedly struggled. Say what you (rightly) will about incandescent bulbs’ inherent vitality inefficiency, together with the corresponding excessive temperature output that they radiate—there’s a elementary motive why they have been the core warmth supply for the Simple-Bake Oven, in any case:

However think about, too, that they didn’t combine any electronics; the sole failure factors have been the glass globe and filament inside it. Conversely, my set up of each CFL and LED mild bulbs inside airflow-deficient sconces in my spouse’s workplace probably hastened each their failure and preparatory flickering, as a result of degradation of the capacitors, voltage converters and regulators, management ICs and different circuitry throughout the bulbs in addition to their core illumination sources.

Evolutionary vs revolutionary

That’s why SANSI’s comparatively contemporary method to LED mild bulb design, which I alluded to within the feedback of my prior teardown, has intrigued me ever since I first noticed and instantly purchased each 2700K “heat white” and 5000K “daylight” color-temperature multiple-bulb units on sale at Amazon two years in the past:

They’re smaller A15, not commonplace A19, in total dimensions, though the E26 base is widespread between the 2 codecs, to allow them to typically nonetheless be used instead of incandescent bulbs (though, not like incandescents, these explicit LED mild bults usually are not dimmable):

Notice, too, their claimed 20% brighter illumination (900 vs 750 lumens) and 5x estimated longer usable lifetime (25,000 hours vs 5,000 hours). Key to that latter estimation, nevertheless, isn’t solely the bulb’s inherent improved air flow:

Versus metal-swathed and in any other case enclosed-circuitry standard LED bulb alternate options:

However it is usually the air flow potential (or not) of wherever the bulb is put in, because the “no closed luminaires” warning included on the sticker on the left aspect of the SANSI packaging makes clear:

That mentioned, even when your set up scenario entails loads of airflow across the bulb, don’t neglect that the orientation of the bulb is essential, too. Particularly, since warmth rises, if the bulb is upside-down with the LEDs beneath the circuitry, the latter will nonetheless are inclined to get “cooked”.

Perusing our affected person

Sufficient of the promo footage. Let’s now have a look at the precise machine I’ll be tearing down right now, beginning with the rest of the box-side pictures, in every case, and as ordinary, accompanied by a 0.75″ (19.1 mm) diameter U.S. penny for measurement comparability functions:

Open ‘er up:

raise off the retaining cardboard layer, and right here’s our 2700K four-pack, which (consider it or not) had set me again solely $4.99 ($1.25/bulb) two years again:

The 5000K ones I additionally purchased at that very same time got here as a two-pack, additionally promo-priced, this time at $4.29 ($2.15/bulb). Since they ended up being costlier per bulb, and since I’ve solely two of them, I’m not presently planning on additionally taking one in all them aside. However I did briefly take away one in all them and exchange it within the two-pack field with right now’s sufferer, so you can see the LED phosphor-tint distinction between them. 5000K on left, 2700K on proper; I doubt there’s every other design distinction between the 2 bulbs, however you by no means know…

Other than the aforementioned cardboard flap for place retention above the bulbs and a piece of Styrofoam under them (full with holes for holding the bases’ finish caps in place):

There’s no different padding inside, which could have confirmed tragic if we have been coping with glass-globe bulbs or flimsy filaments. On this case, conversely, it probably suffices. Additionally word the cleverly designed sliver of literature in the back of the field’s insides:

Now, for our affected person, with preliminary overview views of the highest:

Backside:

And aspect:

Try all these air flow slots! Additionally word the clips that maintain the globe in place:

Earlier than tackling these clips, listed here are six sequential clockwise-rotation pictures of the aspect markings. I’ll depart it to you to mentally “glue” the verbiage snippets collectively into phrases and sentences:

Diving in for illuminated understanding

Now for these clips. Draw back: they’re (understandably, given the excessive voltage operating round inside) cussed. Upside: no even-more-stubborn glue!

Voila:

Notice the glimpses of extra “stuff” throughout the base, due to the revealing vents. Full disclosure and identification of the contents is our subsequent (and final) aspiration:

As ordinary, twist the top cap off with a tongue-and-groove slip-joint (“Channellock”) pliers:

and the ceramic substrate (together with its still-connected wires and circuitry, after all) dutifully detaches from the plastic base straightaway:

Not a lot to see on the ceramic “plate” bottom this time, except for the 22µF 200V electrolytic capacitor poking via:

Built-in and in any other case easy = Low cost

The frontside is the place a lot of the “motion” is:

On the backside is a mini-PCB that mates the capacitor and wires’ soldered results in the ceramic substrate-embedded traces. Across the perimeter, after all, is the series-connected chain of 17 (if I’ve counted accurately) LEDs with their orange-tinted phosphor coatings, spectrum-tuned to generate the 2700K “heat white” mild. And the three SMD resistors scattered across the substrate, two subsequent to an IC within the higher proper quadrant (33Ω “33R0” and 20Ω “33R0”) and one other (33Ω “334”) alongside a tool at left, are additionally apparent.

These two chips ended up producing the majority of the design intrigue, within the latter case nonetheless an unresolved thriller (not less than to me). The one at higher proper is marked, alongside an organization emblem that I’d not encountered earlier than, as follows:

JWB1981
1PC031A

The bundle additionally appears odd; the leads on either side are asymmetrically spaced, and there’s an extra (fourth) lead on one aspect. However due to one of many outcomes from my Google search on the first-line time period, within the type of a Hackaday publish that then pointed at an informative video:

This explicit thriller has, not less than I consider, been solved. Quoting from the Hackaday abstract (with hyperlinks and different augmentations added by yours really):

The chip in query is a Joulewatt JWB1981, for which no datasheet is obtainable on the web [BD note: actually, here it is!]. Nonetheless, there’s a datasheet for the JW1981, which is a linear LED driver. After reverse-engineering the PCB, bigclivedotcom concluded that the JWB1981 should [BD note: also] embrace an onboard bridge rectifier. The one different elements on the board are three resistors, a capacitor, and LEDs.

 The primary resistor limits the inrush present to the massive smoothing capacitor. The second resistor is to discharge the capacitor, whereas the ultimate resistor units the present output of the regulator. It’s attainable to get rid of the smoothing capacitor and discharge resistor, as different LED circuits have executed, which additionally permit the sunshine to be dimmable. Nonetheless, this ends in a really annoying flicker of the LEDs on the AC frequency, particularly at low brightness settings.

Examine the resultant schematic proven within the video with one created by EDN’s Martin Rowe, executed whereas reverse-engineering an A19 LED mild bulb at the start of 2018, and also you’ll see simply how cost-effective a contemporary design method like this may be.

That solely leaves the chip at left, with two seen soldered contacts (one on every finish), and naked on high save for a cryptic rectangular mark (which leaves Google Lens considering it’s the heart of a light-weight swap, consider it or not). It’s not referenced in “Massive Clive’s” deciphered design, and I can’t discover a picture of something prefer it anyplace else. Diode? Varistor to guard in opposition to voltage surges? Resettable fuse to deal with present surges? A number of of those? One thing(s) else? Publish your [educated, preferably] guesses, together with every other ideas, within the feedback!

—Brian Dipert is the Editor-in-Chief of the Edge AI and Imaginative and prescient Alliance, and a Senior Analyst at BDTI and Editor-in-Chief of InsideDSP, the corporate’s on-line e-newsletter.

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