I thought it would be interesting to compare three different power ratings of lamps from the same brand. These lamps came from a retail outlet called One Below, which is the reincarnation of Pound World. The 13W lamp was slightly more expensive than the others.
The circuitry is very typical of how non-dimmable LED lamps have standardised. They've chosen the very simple linear regulator approach, where as much voltage is dropped across the LEDs as possible, and the difference between that and the peak mains voltage (which the capacitor will charge to) is then dropped across the linear regulator chip and dissipated as heat.
That may sound inefficient, but in reality it's a very simple and reliable way to regulate the LED current.
The current through the LEDs is set by a programming resistor which is chosen to have a voltage of around 0.6V across it at the desired LED current. Increasing the value of that resistor reduces the current. Whereas many lamps use two resistors in parallel to fine-tune the current, these lamps have just a single resistor per regulator, which makes hacking them slightly harder as it involves replacing the original sense resistor with a new one, and that is made harder by the aluminium core PCB sucking heat away from the soldering equipment.
Theoretically, the 13W lamp can be hacked to half the power by just removing the sense resistor on one of the two regulators.
One of the best things about these lamps is that you can replace the diffusers with 3D printed versions in any shape and size you desire. But only after reducing the output power. At very low power levels this can make for some very attractive decorative lamps.
Here's a video about the custom lamp cover mod:-
https://www.youtube.com/watch?v=HZKu9QMN5xw
Supporting the channel with a dollar or two on Patreon helps keep it independent of YouTube's quirks, avoids intrusive mid-video adverts, gives early access, bonus footage and regular quiet Patreon live streams.
https://www.patreon.com/bigclive
#ElectronicsCreators
The circuitry is very typical of how non-dimmable LED lamps have standardised. They've chosen the very simple linear regulator approach, where as much voltage is dropped across the LEDs as possible, and the difference between that and the peak mains voltage (which the capacitor will charge to) is then dropped across the linear regulator chip and dissipated as heat.
That may sound inefficient, but in reality it's a very simple and reliable way to regulate the LED current.
The current through the LEDs is set by a programming resistor which is chosen to have a voltage of around 0.6V across it at the desired LED current. Increasing the value of that resistor reduces the current. Whereas many lamps use two resistors in parallel to fine-tune the current, these lamps have just a single resistor per regulator, which makes hacking them slightly harder as it involves replacing the original sense resistor with a new one, and that is made harder by the aluminium core PCB sucking heat away from the soldering equipment.
Theoretically, the 13W lamp can be hacked to half the power by just removing the sense resistor on one of the two regulators.
One of the best things about these lamps is that you can replace the diffusers with 3D printed versions in any shape and size you desire. But only after reducing the output power. At very low power levels this can make for some very attractive decorative lamps.
Here's a video about the custom lamp cover mod:-
https://www.youtube.com/watch?v=HZKu9QMN5xw
Supporting the channel with a dollar or two on Patreon helps keep it independent of YouTube's quirks, avoids intrusive mid-video adverts, gives early access, bonus footage and regular quiet Patreon live streams.
https://www.patreon.com/bigclive
#ElectronicsCreators
The real problem is that most LED lamps are marketed with “equivalent” power ratings to tungsten filament lamps. However, the amount of electrical energy drawn from the mains supply is not equivalent to the amount of light output. This is true for any type of lamp. As all lamps waste some energy in the form of unwanted heat. Plus how many people actually try different lamps to select one with a reasonable brightness for the room, rather than fitting whatever they have / the highest power that they have?
Really lamps should be selected using both Luminous intensity (unit is candela or cd) which is how bright a light is when it it’s a flat surface from one direction of the light source and Luminous flux (unit is lumen or lm) which is the total light output from all directions.
As Clive says, the efficiency of a LED to convert electricity energy to light varies depending on the electrical current and more importantly, the temperature of the semiconductor chip. At higher currents (power levels) it runs hotter, but is less efficient. Hence if you run a LED at half the maximum rated current (LEDs are current operated devices), it will be more efficient than when operated at its maximum rated current, but will obviously have an overall lower light output.
The reason than manufacturers don’t operate LEDs at lower current levels is cost. You would need more LEDs for the same light output.
How does power factor affect consumption?
I like how the design seems to be maturing to a very simple standard.
The first LED house lamp I ever played with was one I wired on my own, mostly similar but it did stay on because I had it on a circuit with three switches and the capacitive coupling through the cable was enough to keep a few LEDs on. I had not considered that that little energy would light them up, but considering the cure seems to be to create extra heat, I don't mind a residual glow. After a decade the filter cap I used degraded, and I suspect that will be one of the most common failure modes with these too.
BigClive always the light of my life! ❤️😁 You're so bright and lovely to watch (actually I honestly just listen to your voice as you are messing with stuff as I clean or tear something up myself)
Why is the power factor so low? 🤔
I tell you what Mr. Clive… aaand… I forgot… because I waited too long, got sidetracked, and stoned.
But no matter. I had no major point to make; that I recall anyway…
Well it's good to know you're out there, somewhere…
You've heard it before, and you will hear it again: Your voice is comforting, Irregardless of the subject matter of a particular video or another… We know what we're talking about.
rock on fellow space traveler, sir.
Just one moment to reverse engineer three light bulbs? isn't that cheating? 😉
I will never not think that one below is a terrible name compared to pound world
I'm 37.4% here for the spudger
sorry if it has been answered before, but "one below … what?"
I have a 36 watt grow lamp. Would you consider a teardown if I sent it to ya'?
I looked at it, maybe hackable, but sm resistors too small for me.
Cheers to you.
1 million subs, nearly there big man.
IMO it'll be the same bulb, but different resistors setting the current. Now lets watch the video and see.
Nah, those are a bit different, LED strips on the other hand are all the same, just different resistors.