## Step 2: [CALCULATIONS]

Now, like any project with electricity, certain calculations are necessary. Although the equations might look a bit threatening, I can assure you that it's quite simple. Before starting your calculations, make sure you have your LEDs' detailed specifications from your supplier.

FV (Forward Voltage) - This is the voltage used by each separate LED. It is expressed as a range, so a minimum and maximum value is present.
AC MAX/MIN - AC Mains are not always at a constant voltage and are not always the same across a whole house. There is actually a range present. In the US, the range is 110-125VAC. In other nations, the range is 220-250VAC.

EQUATIONS
[AC MAX] X 1.4 = A
A / [FV MAX] = [# LEDs]

CHECK
[AC MIN] X 1.4 = B
B / [# LEDs] = C
C represents the forward voltage and must be within the range.

Your final result represents the number of LEDs you can put in each series. Think of this as a basic unit. The total amount of LEDs on the light bulb must be a multiple of this number. In each "unit," the LEDs connect positive to negative in order to distribute the voltage. All the series may then be connected together, positive to positive and negative to negative. Below is a sample of my calculations.

EQUATIONS
125 X 1.4 = 175
175 / 3.8 = 46

CHECK
110 X 1.4 = 154
154 / 46 = 3.3478
C is in range. (exhale)
<p>Awesome work dude.</p>
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.
<p>As far as the color situation, you can use a mix of white to yellow LEDs, like two or three white for each yellow one. You'll have to experiment to see which mix you like best. That will give it a warmer glow more like an incandescent instead of the harsh white you would get if you use only the white LEDs.</p>
umm legal....in what way?
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.
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.
I completely forgot about fuses and such. It justs leaves me with the "what if?" question in my head.
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...
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.
I can't find the instructable at the moment, but it shows how to use the small amount of explosive in a party popper, inserting it into a pen barrel in one end and a some thing in the other (as ammunition) and pulling the string to fire. I cut my finger nail in half cutting an eraser in half for amo, burnt my finger from the explosion, burst my ear drums from the bang and the circular scar from the back of the pen shooting backwards. I'm just glad my parents didn't hear it, otherwise I may have sustained other injuries...
=) Speaking of gunpowder that reminds me of when I was trying to get the powder out of those plastic rings for cap guns with a pair of scissors. I made a cap go off when i stabbed it, and those things shoot fire. Singed some hair on my hand. Scared the crap out of me....<br/>
XDDD
seeing how you guys are talking about stupid things you have done with fire im going to tell my story: So i saw an instructable on how to make flamming fireballs out of cloth and grill starter fluid or whatever its called. so i made them just fine outside and wanted to make more. But i had to use the restroom as in like number 2 if you know what that meens. and if you knew me you would know that i do anything in the bathroom just like i would do anything anywhere, so i made some in the bathrrom. i was stupid enough to try it out to so i put the fluid on the cotton balls and without me relising a lot had gotten on the floor, im guessing it was the fumes. so when i look one of the balls it had started to burn my hand so i dropped it. then BOOM!!! my pants, shoes, my little sisters jeans had all caught on fire. I was still sitting on the toilet saying "WTF!" and then i just stood up and took my pants off, threw them outside and beat them to put the fire out and had completely forgot about everything else in the bathroom. so i went back to wipe and i saw my sisters pants burning up in flames so i took those trying not to burn myself and dowsed them in the house right outside our front door and then hid them so my parants wouldnt fine them. and my shoes, they just went out by themselves. So thats my story, lol my parants still dont know.
You are damn lucky ! You could have burned yourself to the point of needing plastic surgery (grafts from your bum). Why are you trying to self-destruct? Go outside and play with fire! Can I take out an insurance policy on you? I would love to retire rich!
Still can't stop myself from laughing and I read it over a minute ago, seriously, how can you get so unlucky!?!?!?!<br/><br/>I made those fireballs but I used metho and you couldn't hold it but you could throw it at people if you didn't grab it for more than about half a second.<br/><br/>One thing I can say for you, may your parents never, <em>ever</em>, <strong>ever</strong>, <em><strong>ever</strong></em>, <em><strong>ever</strong></em> find out what happened.<br/>
I knew my parents heard the bang, but i dont think they knew I was blowing myself up.
My parents have learned that if there's a bang, they should probably check what I'm doing...
The usually just tell me " Your going to ________ doing that and it will hurt" and then they leave me alone. And 95% of the time im fine. No er visits yet.... The ____ is like a fill in the blank thing. Like fire is burn, homemade turbo fan is get hit, ect.....
Turbo jet is burn and hit? :D
No, I stuck my finger in it.
Not a good Idea.
Ow!!! I want to make it now.
It wasnt actually a jet, its just easyer to say and a lot cooler. It was a really nice electric engine from an erector set (google it if you dont know what it is) and I attached a special part which allowed me to build stuff on that can spin. So I attached the two longest beams on and turn it on. It started to spin so fast, It turned invisible, and I had an instant of stupidity and forgot about it and tried to reach through. I didnt get too far, only half a fingernail. I cant wait to buy rc helicopter blades!!!!!!
Then its a turbo prop.
I would take a picture and post it but I unfortunatly dont have a usb cable for my phone.... and I dont want spend my mony on it though.......maybe Christmas......
It felt wonderful too..... It made a blood blister under my nail and on the tip of my finger and the pressure under my fingernail really hurt, so I had to pop it right befor dinner and I ate with my other hand cause my finger still hurt and was still draining a little. And then the next morning I looked at my nail and it felt just fine, just a little sore when pressed, but the skin under my nail had pulled away halfway back. Its almost done healing now, a month and a half later. as in the skin has almost reconnected fully. IT WAS SOOOOO WORTH IT!!!!!!!!!!!
Funky wording, I call it lighter fluid but there a heaps of words for it, and that is absolutely HILARIOUS!!!!
I don't know how to put this. You're wrong. It's not illiegal. It's just not UL listed. The design is good. This isn't far from how the factories do it. If "you" don't understand the concepts involved, that doesn't make it wrong. If you don't know how to test a circuit to know how it's safe, then don't do it. If you'd like to know how.... this is definitely a place to ask.
Yes, I just found out that it is completely legal. Saw some at walmart and they have a patent pending, but this is the same general idea, not exactly the same.
Good to hear, thanks for telling!
Hello, I have two questions: <br>1. What does the 1.4 value calculation? <br>2. Can I use size rectifier 2A 400V instead of 400V 1.5A? <br> <br>grateful
I think you should add a low-resistance (1&Icirc;&copy; 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.
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. <br> <br> <br>I did everything following your diagram and it was a nice glitter show for a microsecond. It appears about 10 LED's are dead. <br> <br>What did I do wrong? <br> <br>Lance
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?
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?
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.
this could work, do you have an instructable on that .
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 !!
its kindof im practical but nice still
Wow great instructable! Just wondering though <sup>(please forgive me, I'm not as well learned in the field of household electronics as I probably should be)</sup> but how does this save energy? I don't know, but isn't the same amount of energy put into it?<br/><br/>I'm not trying to be negative, and I hope with some explanation I won't be &quot;kept in the dark&quot; for any longer...<br/><br/><sup>*cough* bad pun *cough*</sup> <br/>
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.
don't smoke detectors usually run on batteries? i understand what you mean though
&nbsp;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.&nbsp;
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.)
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.
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.
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.
All Hardwired Smoke Detectors <em><strong>are </strong></em>interconnected
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.
Hmm... if one LED dies in te first series.. all will turn off?<br />