A test to see if ordinary LED lamps can be under-run like Dubai lamps to make them last longer with reduced intensity and heat.
To limit the current I used different values of series capacitor, which has a soft limiting effect, making it compatible with traditional capacitive dropper and linear regulator based lamps.
This technique does not work with some lamps with switchmode based power supplies. They will tend to strobe due to the way the circuitry works.
This project involves mains voltage, and suitable precautions should be taken during your experimentation.
The trickiest bit about making a Dooby lamp is finding a place to put the capacitor. In some capacitive dropper based LED lamps it's easy, since their covers may unclip allowing the original high value capacitor to be changed for a lower one. For other lamps like the glass filament styles the capacitor will need to be put inline external to the lamp. That could be in a lamp extender (if you can get one that is easy to open), in a ceiling rose, in the wiring box of a chandelier or in the lightswitch enclosure. Doing it at the lightswitch opens up the possibilities of letting the lamp be switched between full intensity mode or a lower security/night light mode. With two switches you could have the option of on, dim or off.
A benefit of using a capacitor is that it is a soft, efficient and low noise way of dimming to a fixed level. The power factor will generally be no worse than the original, and a suitably rated capacitor will be virtually indestructible in this application.
From my tests the following 400V AC capacitors worked well for a European 220-240V supply:-
470nF converted most lamps to approximately 2W
220nF converted most lamps to around 1W
100nF converted most lamps to around 0.5W
47nF was not measurable. Probably around 0.2W
22nF was not measurable. Probably around 0.1W
10nF (ceramic capacitor). Some lamps won't glow because they have an internal shunt resistor to avoid nuisance glowing due to capacitive switch-wire coupling. But others will glow at a surprising intensity for the tiny current. (I was really surprised at the intensity of some lamps.)
For 120V supplies the capacitors should be 250V AC film capacitors and the values may have to be higher - like 1uF or more. The capacitors are common and cheap, so they can be experimented with. They can be connected in parallel for higher capacitance.
I used a 1 Megohm resistor in parallel with the capacitors during my tests, as the capacitors can store a charge and may give a slight zap if not discharged. In final use the resistor can be soldered or twisted directly to the capacitor leads.
The capacitors will run cold and should be insulated properly if used behind switches or in junction boxes. That could be done with heatshrink sleeving.
Although the super low value capacitors like 22nF only made the lamps glow dimly, it makes them very suitable as directly viewed decorative lamps or for use as night lights, where very little light will be ample at night. With such low power the lamps can be left running continuously, as they will last a very long time and cost virtually nothing to run.
If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:-
http://www.bigclive.com/coffee.htm
This also keeps the channel independent of YouTube's advertising algorithms allowing it to be a bit more dangerous and naughty.
To limit the current I used different values of series capacitor, which has a soft limiting effect, making it compatible with traditional capacitive dropper and linear regulator based lamps.
This technique does not work with some lamps with switchmode based power supplies. They will tend to strobe due to the way the circuitry works.
This project involves mains voltage, and suitable precautions should be taken during your experimentation.
The trickiest bit about making a Dooby lamp is finding a place to put the capacitor. In some capacitive dropper based LED lamps it's easy, since their covers may unclip allowing the original high value capacitor to be changed for a lower one. For other lamps like the glass filament styles the capacitor will need to be put inline external to the lamp. That could be in a lamp extender (if you can get one that is easy to open), in a ceiling rose, in the wiring box of a chandelier or in the lightswitch enclosure. Doing it at the lightswitch opens up the possibilities of letting the lamp be switched between full intensity mode or a lower security/night light mode. With two switches you could have the option of on, dim or off.
A benefit of using a capacitor is that it is a soft, efficient and low noise way of dimming to a fixed level. The power factor will generally be no worse than the original, and a suitably rated capacitor will be virtually indestructible in this application.
From my tests the following 400V AC capacitors worked well for a European 220-240V supply:-
470nF converted most lamps to approximately 2W
220nF converted most lamps to around 1W
100nF converted most lamps to around 0.5W
47nF was not measurable. Probably around 0.2W
22nF was not measurable. Probably around 0.1W
10nF (ceramic capacitor). Some lamps won't glow because they have an internal shunt resistor to avoid nuisance glowing due to capacitive switch-wire coupling. But others will glow at a surprising intensity for the tiny current. (I was really surprised at the intensity of some lamps.)
For 120V supplies the capacitors should be 250V AC film capacitors and the values may have to be higher - like 1uF or more. The capacitors are common and cheap, so they can be experimented with. They can be connected in parallel for higher capacitance.
I used a 1 Megohm resistor in parallel with the capacitors during my tests, as the capacitors can store a charge and may give a slight zap if not discharged. In final use the resistor can be soldered or twisted directly to the capacitor leads.
The capacitors will run cold and should be insulated properly if used behind switches or in junction boxes. That could be done with heatshrink sleeving.
Although the super low value capacitors like 22nF only made the lamps glow dimly, it makes them very suitable as directly viewed decorative lamps or for use as night lights, where very little light will be ample at night. With such low power the lamps can be left running continuously, as they will last a very long time and cost virtually nothing to run.
If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:-
http://www.bigclive.com/coffee.htm
This also keeps the channel independent of YouTube's advertising algorithms allowing it to be a bit more dangerous and naughty.
I’ll bet an inductor after a bridge rectifier would stabilize some of these lamps.
It would go Capacitor>Rectifier>Inductor>Lamp
I wouldn’t even bother trying to get rid of the internal rectifier unless you care about the voltage drop it adds. Many of these lamps function on DC power just as well as AC.
I think the Dubai style lamp is a very good idea, and with the new energy efficiency scale, to get an A rating you have to make Dubai-style lamps.
I also don't mind the cold white/daylight lamps!
Hey, I have a question. I have an electric water heater for a special project. The heating elements are 240 volts. When they turn on I'd like to have an indicator lamp illuminate. Preferably an LED. How can I go about this? I originally thought find a 120v LED wire it between the two 120v lines and add a diode to one side but does anyone make a 120v single LED?
There is hack to find out the light difference (increase or decrease) without a lux meter on the DiodeGoneWild channel where he made some DIY Dubai lamps from normal LED bulbs.
The hack is to put a solar cell at a distance of 30 cm from the lightbulb and measure the current output of the solar cell. Keep in mind, the CURRENT not the voltage because the voltage of the solar cell doesn't modify visible like the current does under different light exposure. And dont forget to extract the ambient light value of that solar cell because you cant work in the dark so you need a room light always turned on.
Indeed the light (lumens) from a Dubai DIY lightbulb will decrease but there is a sweet peak point where the light is more efficient for the new power of the lightbulb.
To be more precise, and what i believe, Clive is reducing the power needed for a light bulb but increasing efficiency for the new power used which you won't find on normal bulbs.
For example, if Clive makes a 5W/600 lumen lightbulb to use 3 W then the newly obtained lightbulb will give, let's say 500 lumens.
Will NOT emit 320 lumens (like a normal one for 3W from shops) but 500 lumens.
So in the shops, if a normal 3W gives 350 lumens then after the DIY modification, you'll obtain a new 3 W / 500 lumens. (values are fictive for understanding the example).
So yes, basically you obtain a more efficient lightbulb but efficient for the new power used. And of course, as long as the lightbulb was designed to withstand higher power then the new (modified) will last way much longer if it's used at lower power !!!
That's why if you want more bright LED i believe it's better to make the project with higher power lightbulbs, such as 12 or 15 W or higher in order to get a decent 5W highly efficient new lightbulb.
And even if it's not efficient like the new generation ones from the shops (in terms of lumens) because it has been made at home without too many advanced measurements, at least you get guaranteed 50000++ hours for its lifespan so, either way, YOU SAVE MONEY with this modification.
Some will say if you want to increase further the lifespan of the lightbulb, make it light slowly not instantly. maybe with a triac or thyristor.
I remember in 2008 i purchased a LED lightbulb that was turning on slowly, it was very expensive, and the lightbulb is still working but i removed it from the socket because its so weak after all these years. It is a 12W one but it barely lights like a 6W.
Clive, from what i see on youtube there is another method for this project, i saw on that channel, to remove one of those 2 parallel resistors inside the lightbulb.
Could you make another video about this 2nd method by removing and changing the value of one resistor from those 2 parallel resistors so we know which resistor could be the best choice? And/or how to make a LED with a triac or thyristor to light slowly to increase furthermore the lifespan.
I work in Asda and out of curiosity I had a look at the cost price of the £5 pack of two 6.4w filament LEDs they sell, they cost Asda £1.30 or 65p per bulb 😱
Very illuminating
Can you help?
I tried this with a 1pf capacitor and a 1meg resistor & the measured current went up. This is really strange.
What's going on?
You really need your own forum! Love to see what your community would get upto
Excellent Clive
So far I tried with a 470nf capacitor –
a GLS integral max efficiency 806lm 3.8w from toolstation, it reduced the power from 3.8w to 2w but it flickers slightly. Maybe i should pop the lense cover and add a capacitor across the leds? xD
Ive tried a filament LAP 3.8w 806lm from screwfix (which is no longer available to order!) and it reduced the power to 2w and was completely stable.
Ive got one of the older filament Asda 6w bulbs but it stobes.
Ive got a dail 10.5w GLS and it reduced it to 2w and its completely stable. Its not massively bright but good enough for the use i wanted it for.
I also tried some crompton dimmable filament bulbs but they seem to require at least 600-700nf to even turn on (I never measured the power consumption for them)
Ive also tried these in a light fitting that takes 3 bulbs and it seems like only 1 bulb of different brands will light up at any 1 time. Im assuming it comes down to which ever conducts at the lowest voltage? I found it pretty strange that only one bulb would light when theres most definitely power available at each fitting.
Does this work if you use it for a light fixture with bulbs in parallel, I'd assume you'd need to multiply the capacitance by the amount of bulbs in the group, so 2 bulbs would need 940nf (2x 470nf) to run at 2w/bulb
this would be nice for my outdoor lights. especially if i add a little extra wire to overwrite the cap, so that i have the dimmed light come on via a dusk sensor and then a motion sensor hooked up to the full power side of the lights. then i can have full power when i need it and very low and effecientt power for the rest of the night.
How many watts does it take to light a dooby? 😂
I might see if this'll work with some bulbs i found in Screwfix with 8 filaments. 3.8w 806lm.
Thank you, Clive, for all your hard work, the listing was very helpful and comprehensive, I want to have a night light using a LED candle lamp so looking at your list I think I will start with 47nF Cap and work my way up.