Once I did my first teardown of a LED-based gentle bulb almost eight years in the past, I figured it’d be a one-and-done. In coming to that untimely conclusion, nonetheless, I didn’t take into account the added performance (akin to community connectivity) enabled by the lowered energy draw of the LED illumination subsystem versus that of the incandescent precursor. And I additionally didn’t take into consideration the variety of features (dimmable, three-way, and many others.) and legacy type components that LED upstarts would wish to help. Right here’s the to-date teardown checklist, which doesn’t even depend LED illumination sources that aren’t bulb-shaped, like touch-activated and motion-sensing panels:

Right this moment’s teardown “sufferer” falls into the “legacy type issue” class. About three years in the past, I made a decision to swap out round a dozen and a half (to date) of the almost three dozen complete mixture of BR30 and BR40 incandescent bulbs that have been already put in and in use in ceiling “cans” all through the home once we purchased it. The bulbs I’ve up to now transformed to all-BR40 LED successors had two frequent traits:

• They have been straightforward to succeed in utilizing solely a traditional ladder (which, you’ll quickly see, has been useful for not solely preliminary but additionally ongoing entry functions), and
• They have been in locales, such because the kitchen and my workplace, that noticed frequent use, due to this fact significantly benefitting from LED conversion from an influence consumption standpoint.

Talking of which, right here’s one of many “daylight” (5000K coloration temperature) replacements put in in my workplace, each off:

03.26.2024

03.21.2024

03.18.2024

and dimly illuminated:

Whereas I can’t definitively say that I’ve observed a tangible drop in our residence utility invoice post-swap, I definitely now really feel higher about turning (and conserving) the lights on than I did earlier than. That mentioned, the transition hasn’t been good. To my earlier “dimly illuminated” remark, all of the multi-bulb circuits I’ve transformed to date are “fed” by dimmer switches, thereby necessitating dimmer-compatible LED lights. Particularly, I’d purchased a few these Sunco bulb 10-packs:

to go away me with some spares stock, which I’d hoped I wouldn’t must faucet into for some time. Take a look at this conceptual cutaway of what mine supposedly appear to be inside:

Granted, mine are 17W/100W equivalents, not the 7W/50W equal one proven right here. Regardless…maintain that thought 😉

Are they “zero flickering”? Not precisely. The majority of the time I attempt to use them? Sure, really. However…nicely, let me begin by requoting a portion of my December 2023 teardown (this time with grammatical corrections made by yours really to the authentic supply):

Most dimmers put in as we speak are designed for use with high-power circuits to drive conventional filament lamps which have been all fairly uniform and dimmable by only a voltage change. LED lamps, however, are low-power and extra complicated. An LED bulb is a solid-state product that has in-built circuitry (known as a driver) that takes high-voltage AC enter present and converts it to low-voltage DC present to drive the LEDs. Moreover, driver specs usually are not uniform throughout the LED business.

There are a lot of several types of dimmers put in in properties and places of work, of varied specs (e.g., resistive; modern and trailing-edge and digital). So, when utilizing new LED lamps with current dimmers, matching previous know-how with new will be difficult.

 The drivers in dimmable LED lamps may fit with many sorts of dimmers however not all. As an illustration, LED lamps are inclined to work higher with trailing-edge dimmers reasonably than modern dimmers. An current dimmer may have a minimal load that’s too excessive for an LED lamp. For instance, a 60 W filament lamp might use a dimmer that has a minimal load of 25 W, however the alternative LED has an influence ranking of 6.5 W – under the extent required by the dimmer. Devoted LED dimmers conversely have a really low minimal energy ranking.

The dimming expertise may also be totally different with LED. General, the LED dimming efficiency is regulated by the aptitude of the LED driver/chip and the compatibility of the dimming circuit. Since there are an enormous variety of potential combos of lamps and dimmers, it is vitally troublesome to supply an LED lamp that works in all dimming environments.

LEDs at present have a decrease dimming vary than a filament lamp – LEDs at present dim all the way down to about 10% of the full gentle output whereas filaments might go all the way down to 1-2%. Low-voltage transformers as used with MR16 12V spotlights additionally add to the complexity.

A few of the points which will happen when a dimmer is incompatible with an LED lamp are:

• Flickering – Lamps will flicker (may also happen if a non-dimmable lamp is used).
• Drop-out – No gentle output on the finish of the size.
• Useless journey – When the dimmer is adjusted, there isn’t any matching change in gentle output (gentle might not dim to acceptable stage).
• Not clean – The sunshine output might not go from dim to brilliant [editor note: and/or vice versa] linearly.
• A number of lamps – points might grow to be obvious when a number of lamps are added.
• Harm or failure – LED driver, circuit or LED is broken or fails.
• Load under minimal – The facility load of the LED lamp is under the minimal required by the dimmer.
• Combined fashions – Totally different fashions of LED will probably have totally different drivers, since drivers behave otherwise this might lead to dimming points.

I’ve personally skilled variants of a number of of those imperfections to date:

• One/a number of/all of the bulbs in a given circuit will activate solely dimly, and flicker-filled, even at a supposed “full energy” dimmer swap place.
• One-to-multiple of the bulbs received’t activate in any respect, even with the others absolutely illuminated.
• Dimming the circuit causes one-to-multiple of the bulbs to both flip utterly off or to stubbornly stay absolutely illuminated.
• and many others.

The “repair” in all these circumstances? Flip all of them off and again on once more.

And concerning my earlier “spares stock, which I’d hoped I wouldn’t must faucet into for some time” remark…once more, actuality hasn’t matched the hype. I’m reminded of the remark left by reader “vandamme0” to that earlier December 2023 teardown:

Right this moment I realized…you could make outrageous lifetime claims primarily based on single diode reliability at optimum temperature, and no person calls you out on it as a result of no person retains receipts for 18 years, 50,000 hours, or no matter you declare.

Up to now over the previous three years, I “assume” I’ve had three BR40 LED bulbs fail (which, in the event you’ve already performed the mathematics, you notice compelled me to purchase extra spares). Maintaining in thoughts that “electronics issues that break make nice teardown candidates”, I held onto them, one in all which is showcased right here. That failure fee might not appear unhealthy within the grand scheme of issues, till you notice that:

• They characterize ~20% of the inhabitants of LED bulbs that I initially put in, and
• None of the remaining BR30 and BR40 incandescent bulbs, all of which once more have been already put in and in operation once we arrived right here a decade in the past, have failed.

Once I say “failed”, I ought to make clear. They “sorta” failed. After I’d activate a financial institution of lights for some time, one of many bulbs would spontaneously flip off utterly. Turning the financial institution of lights off and again on once more wouldn’t instantly resuscitate it. But when I waited some time, the bulb would come again on…once more, just for some time. I observed that if I unscrewed it and eliminated it from the “can” it’d resurrect extra rapidly. Regardless, as time went on, the offender would fail extra quickly and take longer to revive; finally, I’d simply hand over, seize the ladder, and swap it out.

The probably potential failure mechanism, I think (and you’ll have already discerned), is warmth. Incandescent bulbs get fairly heat in ventilation-deficient “cans”, thoughts you, however the one factor they’re “cooking” is their filaments. With LED bulbs, however, there’s not solely the LEDs themselves to contemplate but additionally all of the circuitry within the base. And in a ceiling “can” there’s one different issue to contemplate; the bulb is pointing downward, which implies that (as with equally oriented CFL bulbs I’ve used and disassembled prior to now) the warmth rising off the LED array finally ends up baking the circuitry within the base above it. Lest you surprise, by the way in which, if I’m utilizing my bulbs in an inadvisable configuration, this “inventory” Sunco picture ought to set your thoughts comfy:

Sufficient setup; let’s dive into the dissection. I’ll as-usual begin with some overview photographs, accompanied by a 0.75″ (19.1 mm) diameter U.S. penny for measurement comparability functions:

Some closeups of the markings across the aspect:

And eventually, the tip of the bottom, each coin-accompanied and standalone:

Final time, the globe (I belatedly realized, to my dismay) was:

• Glass
• Sealed, and
• Fuel-filled

This time, conversely, it was plastic and positively not sealed:

Offering a handy pathway to the inside:

Mission completed:

Rim variance across the circumference:

And now what you’re all actually right here to see:

Eradicating these two screws within the earlier pictures didn’t get me very far:

so, I redirected my consideration to the bottom:

That’s extra prefer it:

Right here’s one other closeup of the entrance of the PCB “plate”, this time unencumbered by its prior environment, revealing the ring of “daylight” coloured LEDs, a smattering of different circuitry (the IC at left marked BP5178F is the LED fixed present driver, whereas the one at backside proper labeled TB120S is the bridge rectifier, each from unknown producers), and the pass-through connection for the 2 wires on the opposite aspect:

However what’s that different two-lead pass-through connector for? Let’s flip the plate over:

It’s…umm…an electrolytic capacitor:

At this level, with no lack of intentional snark, I’ll reinsert the conceptual cutaway from earlier:

Giggle snort 😉

We’re virtually performed; let’s get that steel “dish” (performing primarily as a heatsink, methinks…be aware the thermal paste residue) beneath the “plate” off to see if there’s something beneath of be aware:

And the reply is…nope. That’s all, of us!

As at all times, your ideas are welcome 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 publication.

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