{THE LED LIGHTBULB}

With energy at shortage, we strive to conserve. Although we attempt to buy the greenest electronics and turn them off as much as we can, we still find ourselves with those energy wasting incandescent bulbs or those mercury infested CFLs. The immediate solution that comes to mind to switch to LED light bulbs, which is then stricken down by the fact that LED spots are still at an extremely high price, making it cost a fortune to convert over all of your existing fixtures to this technology. But this is instructables, so we can make our own! What we will end up with is one of the most energy efficient light bulbs you have ever had in your midst, made at a ridiculously low cost. This will save you $100s of dollars throughout the lifetime of the bulb; so feel free to write me a check for the calculated amount!

Step 1: [SUPPLIES]

With LEDs at such high costs, you must know a tremendous supplier. I ordered most of my supplies from two main sources, LED Shoppe and All Electronics. I have found these suppliers to be the cheapest and most reliable. I ordered a large quantity of supplies, since I am going to make several bulbs of various sizes, which made the supplies cheaper. Below are the list of things I needed for this project:

LEDs - I used 5mm LEDs. You can change the type of LEDs as long as you augment the calculations accordingly.
Bridge Rectifier - Converts AC to DC.
Perfboard - The size of perfboard you buy will depend on the size of light bulb you wish to create.
Soldering Iron and Accessories - The cheapest of soldering irons will do.
Base Plug - This product has a normal bulb's base at one end and a normal household outlet on the other. Your local hardware store will most definitely have some.
Cable Ties - The question here is not if you have them, but, rather, how many hundred of them do you have.
Cardboard - This is the main support piece for all the component of the bulb.
Wax Paper - I used a silicon cookie sheet (that rolled up blue thing) instead. You can use practically anything that has a high temperature tolerance and doesn't conduct electricity, but I have found these to be the best materials for the job.
Drill and Small Bit - I used a 1/8" drill bit.
X-ACTO Knife and Whole Puncher - These items will be used to prep the insulation.
20AWG Wire and PVC Pipe - These are required to connect the bulb's base to the rest of the assembly.
Multimeter - I always keep my multimeter handy in order to check conductivity and make sure there are no shorts.

Comments

[rmd6502]

I think you should add a low-resistance (1Ω or so) 3W resistor to help regulate the current for the LEDs. Problem is they all have different specs, so some LEDs will drop less voltage, leaving too much for others - the resistor will help limit the current. Better still, a LED current regulator chip.

[LGProspects]

So I did the build I am in the US so based everything off here. 5MM leds, 3.0-3.2 FV. Did the math and got 55 LED's needed. During the check it came back as 2.8. So I figured it was UNDER voltage at 55 so went for it.


I did everything following your diagram and it was a nice glitter show for a microsecond. It appears about 10 LED's are dead.

What did I do wrong?

Lance

[ogled002]

Can anyone tell me if I can go up to 7 series at 46 LEDs each, with the same one size bridge rectifier that is used in this project or do I need to go bigger on the bridge rectifier?

[jasonm621]

Can you insulate your circut with something like that paint on electrical tape stuff or hot glue? Just for ease of construction by glueing stuff together rather than zip ties... Just a thought... Just wondering the safety of insulating with hot glue cause its easy, cheap, and readily available. Not to mention one less step of assembly... Any thoughts?

[TotalLED]

You can also use a PC power supply to run a number of LED's bulbs Supply volts @ 5vdc...low side output. I have LED's thru-out the hole house using one 850 watt PC supply. Bypassing standard AC voltage to the use of one AC outlet....3 years running with zero troubles.

[xana]

this could work, do you have an instructable on that .

[nacho.cheese]

hi aandre, Afew days ago I bought all the material that you said in this instructable, I want to make the small one. My problem is how to assemble all the leds and the rectifiers...!!! could you help with this, do you have more pictures for the part of the rectifiers?? Pictures helps a lot!! more than text !!...so I appreciate if you could send some photos... Im doing a proyect for a school. thanks !!

[junits15]

its kindof im practical but nice still

[jaesungauzakim]

Hmm... if one LED dies in te first series.. all will turn off?

[meissler]

Could you just use any 12V power chord (like a charger for a computer or something) and hook the +/- ends up to the right areas? Of course use resistors too. Would that work or no, not really?

[downgrade]

 Yes, it would. You could also try to find a wallwart to some broken or lost electronic device and use that. A DC power supply would bypass the the rectifier as well. It would be more likely to last longer (read: fewer parts = fewer issues, generally but not always). Hopefully whatever power supply you find has some power regulation going on so it would be less likely to spike and such.

Long story short: yes, and for the most part I would recommend it, especially if you go with 12v you could easily convert it to an off grid solar project as well, since smaller projects like that stick with 12v.

[breakspeare832]

Is it okay if the 20awg wire is rated for automobiles?

[lmarka]

Hi! Is it possible to add a PWM controller (maybe adding a capacitor after the rectifier to run the whole thing at DC) to this project??
Everything I found so far is for low voltage, don't know if it would be as simple as slapping in the Mosfet in series with the LEDs.

[ramedia]

For those who don't have the technical chops,  I found these for $10 each (2 for $20).  They produce the equivilant of a 20watt bulb's light.  http://www.overstock.com/Home-Garden/Grip-30-LED-Light-Bulbs-Set-of-2/3339673/product.html?cid=123620&fp=F&ci_src=14110944&ci_sku=11432846

[Highjump44]

 How fast was the shipping bcz im in the US and I just found out its coming from Hong Kong

[trekman]

I built 2 of the small LED light bulbs following the Instructable. I used the same rectifier and had 46 LEDs in series. I made these as a night light and they worked fine but only for a couple of weeks. I also used the LED array wizard but it wanted a 2.2K resistor added to the circuit. I tried the resistor but it dims the LED about 25%. What can I do to make these last longer? Thanks

[Teleran]

I gave up on the Idea of using a TI783 Regulator, because many things need to be done to keep the thing working. I kept on measuring the Line Voltage for Max Avg and Min, it goes from 136 Volts AC down to 118 Volts AC. I measured the outputs on my inverters, and it is a nice constant 119 Volts AC. So now all the 46 Led Lights that I made work perfectly, on Batteries, not using Hydro, giving a nice constant light with no flickering at all! Thank you for making this project available. Now it really will save me some money in the long run. Teleran.

[orthodoxmonster]

Questions: in this series crt, 110-125Vdc/1.5A is initially applied to 1st Led (rated at 3.2-3.8Vdc/30mA, doesn't this cause damage to the Led? Thanks.

[Teleran]

I measured the line Voltage here for a few days, and it goes from 119 VAC to 133 VAC. So I'm thinking now or making a Regulator which can be plugged into a Surge protected outlet, which prevents the LEDS from damage, and then adjusting the regulator to about the Voltage that 46 LEDS with a Forward Voltage of 3.4 volts DC to 3.6 Volts DC. This way the LED Arrays are immune to AC Voltage fluctuations, and Surges, and will even stay on during minor Brown Outs, without flickering, or turning off, having a nice steady output. Here in the Third World LED Projects cost more than just a few bucks, and it is nice to be able to have efficient lighting, running on AC or hydro, that last for many years, instead of flickering when the voltage drops by more than seven volts AC, or turning off when the voltage increases to more than what it can take. I've been looking at low parts count, IC regulators that might be able to work these LED Lights. In the past I made DC operated LED Lights replacing 450 Watts of Hydro lights with 24 watts of LED lights. Even after 4 years they are still working! Teleran

[Teleran]

Hi: Lolzertank:

I used 5 mm Ultra Bright White LEDS. VF is in the range of 3.4 Volts to 3.6 Volts. The Hydro here, is in the range of 115 +/- 5 Volts AC 60 Hz. It's the Country, things go up and down. The Math given did not account for numbers on the other side of the decimal point. So 46.05263 was rounded off to 46 LEDS for a Voltage of 125 Volts AC or 175 Volts DC..

Using the Math given 120 Volts X 1.4 = 168 Volts DC.
168 Volts DC/3.6 VF Max = 46.6666 # LEDS Do we round off to 47 or leave it at 46?

Check
110 X 1.4 = 154 Volts DC
154 Volts DC/47 # LEDS = 3.27 Volts this is lower than 3.4 Volts VF Min.

The AC Voltage range it will work in is then:

47 # LEDS x 3.4 VF Min = 159.79 Volts DC/1.4 = 114.14 Volts AC Min

47 # LEDS x 3.6 VF MAX = 169.2 Volts DC/1.4 = 120.857 Volts AC Max

this is a 6.717 Volts AC Variation.

I used 46 LEDS

46 # LEDS x 3.4 VF Min = 156.4 Volts DC/1.4 = 111.7 Volts AC Min

46 # LEDS x 3.6 VF Max = 165.6 Volts DC/1.4 = 118.28 Volts AC Max

I made 9 all the same type with 46 LEDS in series, powered by a Bridge Rectifier. No Epoxy this time. 2 failed after 2 seconds of power on. The rest worked Ok so far.

I'll monitor the line voltage, for maximum and minimum spikes for a while, see what the AC voltage variation actually is. Might have to fix this with a resistor, or more LEDS or something??

Teleran

[Teleran]

(removed by author or community request)

[lolzertank]

Does your line voltage tend to spike a lot? Also, if your LEDs have a forward voltage below 3.8V, (they probably do), you'll need a couple more LEDs in series. You're not going to get 100,000 hours out of them even in the best conditions. 5mm LEDs' heatsinking is so poor that only the best 5mm LEDs (Nichia, Cree) will survive about 1000 hours before the phosphor or the die failing. Even if it survives that, epoxy on the LEDs will turn brown in much less than 100,000 hours.

[barligea]

how cool is that ...let there be light...the efficient way... great post!

[Kryptonite]

Wow great instructable! Just wondering though ^{(please forgive me, I'm not as well learned in the field of household electronics as I probably should be)} but how does this save energy? I don't know, but isn't the same amount of energy put into it?

I'm not trying to be negative, and I hope with some explanation I won't be "kept in the dark" for any longer...

^{*cough* bad pun *cough*}

[Asbestos]

This saves energy because LEDs use fewer watts to produce the same amount of light as a regular (incandescent) bulb. (Watts is the amount of energy used over time, so each minute that this is on it uses fewer total joules than each minute that an incandescent is on.) This is because LEDs produce light much more efficiently than incandescent bulbs. So this draws less energy than a regular bulb from your wall socket. Even though the socket always has the same number of volts, it will only give the amount of energy being drawn by the appliance. So, for instance, your TV draws a lot more energy from the wall (and from the power company) than your smoke detector. So this gives the same amount of light as a regular bulb, but draws less energy from the power company to do so.

[Kryptonite]

Ahhh, thank you for filling that large blank space behind my eyes. I believed that the same amount of electricity was put into the appliance no matter how much it needed, but the appliance would not take as much in depending on how much it needed. Thank you for your very descriptive response.

[budman0312]

don't smoke detectors usually run on batteries? i understand what you mean though

[downgrade]

 Not all of them, more and more places are putting battery backed detectors that run off the grid power (the battery being there for power outage). That way it is less likely you will forget to change the battery and have a worthless hunk of plastic on the wall/ceiling. 

[germanudo]

All Hardwired Smoke Detectors and interconnected with each other. You have to run a 3 Wire to each smoke Detector. The black one (hot) the white one ( neutral) and the red one is for the communication between each Smoke Detector. The reason for that is. If one Smoke Detector makes an alarm , all other Smokes make an Alarm to. Only to the first Smoke you run a two Wire. The Battery is is for the Alarm in each unit. If the the Power is cut of, each Smoke will make a beeping sound every so often. The Battery is not really for a Power outage. By the way, that is one of the best investments in your live . ( Your kids play with a lighter start a fire and you sleep. So when the Smoke in the Kids rooms goes on, you have an Alarm in every other room that got a Smoke.)

[downgrade]

Not ALL hardwired detectors are interconnected like in my last residence. It ran off either the wiring or battery. I learned this in attempts to not to scare everyone when cooking steaks.

[germanudo]

If they are proper installed by a professional Electrician, they would be all interconnected. And for sure you would not have Hardwired and Battery operated mixed together. That's so wrong. You should also, never, ever hardwire different Brand/Types of Smokes together.

[downgrade]

Using any definite will get you in trouble. Accept that there is more out there to skin a cat. I have plenty of grid based products with battery back ups (both rechargeable and not). These were builtin when the building was constructed, I first pulled battery, alarm continued, replaced battery pulled hard wire, alarm continued, pulled both and nothing, and no one else ended up being aware surprisingly. So if it wasn't a smoke detecotr and just coincidentally went off when smoke was present you are right, if not you are probably just mostly correct with exceptions, as there almost always are.

[germanudo]

All Hardwired Smoke Detectors are interconnected

[Speedmite]

Nice idea and instructable. Im not good at calculations though..... I was just wondering if this is legal or not. I personally like the incandescent bulbs. florescent bulbs are fine, except the mercury. Im not to big on the white leds because the look cold like somone died unlike the freindly yellowish light of incandesent. And yellow leds, are well, yellow. But nice Idea. I like the effort for cleaner ways that many people lack.

[aandre]

umm legal....in what way?

[Speedmite]

Well, I would think that you cant just plug in any science creation, hoping that it works and doesn't cause something crazy to happen. I mean, this is 120v your dealing with. If you soldered something wrong you could burn a house down or cause an explosion. Im sorry if you take this in a negative way, but I'm more cautious than many people. And no, I dont have any affiliation with the law. Just my best guess that it might not be legal.

[Kryptonite]

I personally don't see what's wrong with it, there should most likely be precautions that one must abide when doing this, as with anything, but with today's modern technology almost everything has a power trip of some sort, so if it shorted out or screwed up some how it would probably turn off. Just wondering, where do you live? I'd like to do a little research if I can about the laws and regulations about this.

[Speedmite]

I completely forgot about fuses and such. It justs leaves me with the "what if?" question in my head.

[Kryptonite]

Fair enough, better to be overly cautious then not cautious enough. That's why I cut my finger nail in half, burst my ear drums, burnt my fingers and left a circular hole in my finger, all within 2 seconds. Never, ever be stupid with party poppers...

[Speedmite]

How did you manage that? My freind stuck his hand on a hot stove for 5 seconds to prove he was a man. I wasnt there, but i doubt it was five seconds and he did go to er. and he has scars. But it proves nothing and I recommend you dont do that. It only proved idiocy.