Once I did my first teardown of a LED-based mild bulb practically eight years in the past, I figured it’d be a one-and-done. In coming to that untimely conclusion, nevertheless, I didn’t contemplate 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 consider the range of features (dimmable, three-way, and so on.) and legacy type components that LED upstarts would want to assist. Right here’s the to-date teardown listing, which doesn’t even rely LED illumination sources that aren’t bulb-shaped, like touch-activated and motion-sensing panels:
At the 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 this point) of the practically three dozen whole mixture of BR30 and BR40 incandescent bulbs that had been already put in and in use in ceiling “cans” all through the home once we purchased it. The bulbs I’ve so far transformed to all-BR40 LED successors had two frequent traits:
- They had been simple 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 had been in locales, such because the kitchen and my workplace, that noticed frequent use, subsequently notably benefitting from LED conversion from an influence consumption standpoint.
Talking of which, right here’s one of many “daylight” (5000K shade temperature) replacements put in in my workplace, each off:
and dimly illuminated:
Whereas I can’t definitively say that I’ve seen a tangible drop in our residence utility invoice post-swap, I actually now really feel higher about turning (and maintaining) the lights on than I did earlier than. That stated, the transition hasn’t been good. To my earlier “dimly illuminated” remark, all of the multi-bulb circuits I’ve transformed to this point are “fed” by dimmer switches, thereby necessitating dimmer-compatible LED lights. Particularly, I’d purchased a few these Sunco bulb 10-packs:
to depart me with some spares stock, which I’d hoped I wouldn’t have to 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, truly. However…nicely, let me begin by requoting a portion of my December 2023 teardown (this time with grammatical corrections made by yours actually to the authentic supply):
Most dimmers put in at present are designed for use with high-power circuits to drive conventional filament lamps which had been all fairly uniform and dimmable by only a voltage change. LED lamps, however, are low-power and extra advanced. An LED bulb is a solid-state product that has inbuilt 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 trade.
There are lots of several types of dimmers put in in houses and workplaces, of varied specs (e.g., resistive; modern and trailing-edge and digital). So, when utilizing new LED lamps with current dimmers, matching previous expertise with new could be difficult.
The drivers in dimmable LED lamps may go with many kinds of dimmers however not all. As an illustration, LED lamps are inclined to work higher with trailing-edge dimmers somewhat 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 could use a dimmer that has a minimal load of 25 W, however the alternative LED has an influence score of 6.5 W – under the extent required by the dimmer. Devoted LED dimmers conversely have a really low minimal energy score.
The dimming expertise can be totally different with LED. Total, 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 doable mixtures of lamps and dimmers, it is extremely tough to provide an LED lamp that works in all dimming environments.
LEDs presently have a decrease dimming vary than a filament lamp – LEDs presently dim all the way down to about 10% of the overall mild output whereas filaments could go all the way down to 1-2%. Low-voltage transformers as used with MR16 12V spotlights additionally add to the complexity.
A number of the points that will happen when a dimmer is incompatible with an LED lamp are:
- Flickering – Lamps will flicker (may happen if a non-dimmable lamp is used).
- Drop-out – No mild output on the finish of the dimensions.
- Useless journey – When the dimmer is adjusted, there is no such thing as a matching change in mild output (mild could not dim to acceptable stage).
- Not clean – The sunshine output could not go from dim to vibrant [editor note: and/or vice versa] linearly.
- A number of lamps – points could develop into obvious when a number of lamps are added.
- Harm or failure – LED driver, circuit or LED is broken or fails.
- Load under minimal – The ability load of the LED lamp is under the minimal required by the dimmer.
- Combined fashions – Completely different fashions of LED will probably have totally different drivers, since drivers behave in another way this might lead to dimming points.
I’ve personally skilled variants of a number of of those imperfections to this point:
- 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 change place.
- One-to-multiple of the bulbs gained’t activate in any respect, even with the others absolutely illuminated.
- Dimming the circuit causes one-to-multiple of the bulbs to both flip fully off or to stubbornly stay absolutely illuminated.
- and so on.
The “repair” in all these instances? Flip all of them off and again on once more.
And concerning my earlier “spares stock, which I’d hoped I wouldn’t have to 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:
At the moment I realized…which you could make outrageous lifetime claims based mostly on single diode reliability at optimum temperature, and no one calls you out on it as a result of no one retains receipts for 18 years, 50,000 hours, or no matter you declare.
Up to now over the previous three years, I “suppose” 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). The primary one obtained tossed within the trash, after which I remembered that “electronics issues that break make nice teardown candidates” and held onto the newer two, one among which is showcased right here. That failure charge could 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 had 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 fully. 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 seen that if I unscrewed it and eliminated it from the “can” it’d resurrect extra shortly. Regardless, as time went on, the offender would fail extra shortly and take longer to revive; finally, I’d simply quit, seize the ladder, and swap it out.
The almost certainly potential failure mechanism, I believe (and you could 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 up to now) the warmth rising off the LED array finally ends up baking the circuitry within the base above it. Lest you marvel, by the best way, if I’m utilizing my bulbs in an inadvisable configuration, this “inventory” Sunco picture ought to set your thoughts relaxed:
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 dimension comparability functions:
Some closeups of the markings across the facet:
And at last, the tip of the bottom, each coin-accompanied and standalone:
Final time, the globe (I belatedly realized, to my dismay) was:
- Glass
- Sealed, and
- Gasoline-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 images 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 facet:
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 metallic “dish” (performing primarily as a heatsink, methinks…word the thermal paste residue) below the “plate” off to see if there’s something beneath of word:
And the reply is…nope. That’s all, of us!
As all the time, 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 e-newsletter.
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