Instructables
Picture of AC-LED Night Lamp
INTRO.

This AC LED Night Lamp is dedicated to my friend and adviser *qs*. Without his help I could not have done it.
This Night Lamp runs on AC and is also a Emergency Light when run on the UPS of your PC. during power cuts.
 
Remove these adsRemove these ads by Signing Up

Step 1: STEP-1

Picture of STEP-1
FIXING THE LED's

First of all we will fix the LED's to the Perforated Hard Board.
Fix a row of 5 Blue LED's each on both sides of the Perf Board.
Then fix 6 rows of 5 White LED's in between the rows of Blue LED's
That is in total 10 Blue LED's and 30 White LED's = 40 LED's.
After fixing the LED's to the Perf Board we will wire the Circuit.
Please see the next Photograph for guidance.

Step 2: STEP-2

WIRING THE CIRCUIT.

Follow the Circuit as per the Diagram, The Circuit diagram is very easy to follow as it shows all the polarity of the LED's clearly.
The step down Transformer is a 220 volts to 12 volts. AC.
Blue and White LED's working voltage is 3.3 volts.
Therefore 12v X 1.4 = 16.8 divided by 3.3 = 5.090 so I have taken 5 LED's per row.
This is as per the calculation of my friend **qs** in his Instructable AC with LED's.
A change over SPDT switch is connected for Night lamp (Blue) and Emergency Light (White)
Care should be taken to keep the POLARITY of the LED's as per the circuit diagram.

Step 4: STEP-4

Picture of STEP-4
FIXING THE TRANSFORMER UNIT

Fix the Stepdown Transformer in a Metal Box.
Fix a Wooden batten to the Cover of the metal Box with a up & down JOINT.
Fix the LED Light Assembly to the JOINT with screws.
Connect the output wires to the light assembly.
Fix a 2Pin male plug to the input wire of the Transformer.
Please see Photograph for guidance.
THE NIGHT LAMP PLUS EMERGENCY LIGHT IS READY FOR USE.
1-40 of 47Next »
Abirboy1 year ago
it was simply awesome
fcat13 years ago
Hello mate,

From your 10mm LED AC light, with 18VAC (25.2 Vpk), u have 2 parallel sets of (6led x2) connection correct ? Roughly how many more 6x2 led can be parallel added to it ?

What if with household 240VAC, a .22uF & 1K ½W resistor, 7led x2, any limitation of parallel connection ?

By adding one Bridge Rectifier, should be able to filter the flicker effect right ?
Dipankar (author)  fcat13 years ago
On 240VAC, a .22uF & 1K half Watt resistor,
you can put up to 30+30 led's on a 500 milli watt 12 volt step down Transformer.
If you put more then 30+30 the light starts to go dim, but it will glow.
pl clarify- on 240vAC, 30+30 leds can be used with a .22uF & 1K half Watt resistor. Alternately use Step DnTransformer (230AC-12vAC ) for LEDs. Am I correct? your sentence is not clear..
satpathi
Dipankar (author)  satpathi2 years ago
NO. For using 220 volts with a .22uF & 1K half Watt resistor, the circuit is different. See my LED TUBE LIGHT Instructable.
fcat1 Dipankar3 years ago
Read lots of your post & QS's, about using LED with AC,

The max number of LED can direct connect to household is 240 * 1.4 = 336Vpk 336 / 3.3 (led Vf) = 101 minimum number of LED directly connect to VAC.

1) With lower number of LED, I need a .22uF & 1K ½W Resistor, does this C + R set support, as randomly as 45 + 45 led's ?

2) With this C + R combo, does it support four legged Superflux LED ?

Thanks mate : )
Dipankar (author)  fcat13 years ago
101 minimum number of LED directly connect to 240 VAC.
Your calculation is correct but it should be 101+101LED's.

Regarding four legged Superflux LED, I have no idea, never used it.
knektek4 years ago
in the schematic you used a step up transformer. its supposed to be less windings on the secondary coil.
Dipankar (author)  knektek4 years ago
It is a step down transformer, sorry to have placed the transformer in the wrong direction.
olie8545 years ago
your schematic is eligible plus and minus wires seem to be connected I cannot tell where you hook the end of the led strings to even though i already know, And if you are going to mess with act there is no plus and minus wires act is alternating current meaning at one point one wire is + and the other is - then 1/120th or 1/100th of a second later they flip and it continues, now what makes it an emergency light maybe no power, oh wait it needs electricity to operate, what would you use it for. this kind of thing can be bought in a dollar store or thrift shop even online kind of a waist of LED's in my eyes.
Dipankar (author)  olie8545 years ago
Hi olie854,
Read the second line in INTRO "This Night Lamp runs on AC and is also a Emergency Light when run on the UPS of your PC. during power cuts."
It works that's all. If you cannot follow the circuit Diagram then I can't help it.
I have used + & - because there has to be a Phase(+) and Neutral (-) in every cicuit.

added to my comment the + and - on the LED's is sooooooooooo confusing also you have a connections on the bottom left and bottom right that have no connection dot should there be one I assume so.
Dipankar (author)  olie8545 years ago
Dont go for DOTS see where it is connected.
5 rows of LED's are connected alternatively so that when the AC current flows, it goes through the ROWS alternatively, and half the time one row is on and the other is off.
You can forget the (+) & (-) of the transformer as it is AC.
This Diagram is for those who do not have a college education like me.
We do everything in practical and it works.
college education I am in high school any one can Google these sort of things to find what they need i learned what everything is and what it does with a buddy and the Internet, you don't really need to be smart to read or write a schematic you just need to know what it means.
agreed. and i want to add: there are some books, i dunno if Dipankar likes reading much, but fact is, i'm 14 now, and i'm building a robot. with age of 8, i built my first full adder, because you can read all these things in internet or books.
LOL! I built my first full adder at the end of 2nd grade... 8 years old too! Though I'm not making a robot...
ok, update: my robot project paused, i didn't find a battery for powering it without being too heavy for being transportet by the bot. i think the problem was the fact that i was using an IBM/Lenovo T30 as control unit, which simply is too heavy for my motors.
Try using cells extracted from lithium drill batteries. The Dewalt 36V is a good choice since it's stuffed with 10 A123 26650 M1 3.2V 2.3Ah cells that can each supply 70A, more than you should need for a robot. The A123 cells are as safe as nickel (NiCD, NiMH) chemistry too. You'll need a hobby charger with a "LiFe" setting and run times might not be the greatest. The good thing is, with a proper charger, the A123 cells can be charged in 20 minutes. RC packs could work too, but LiPOs are very dangerous if abused.
if you "do everything in practical", and don't even make correct diagrams, then i wonder y you are still alive.
OK I see that you can use it on a ups but the plus and minus at the end of the led string are useless even confusing get rid of them i did not understand that you wanted them in parallel loops and what are the little arrows on the LED's the current always flow from the anode to cathode in the direction of the triangle. but still ac is ac no + no - it alternates so the + and - on the transformer is wrong. you also have the emergency light well nothing changes unless you switch so how does that make it an emergency light also would a rocker or toggle switch be easier those switches can be difficult to move sometimes and there is little grip on them.
the little arrows on the LEDs are light. if there werent arrows, it would be diodes. but with arrows, it are something emitting diodes, where the something is mostly light, so LED sign is diode sign with arrows.
Dipankar (author)  olie8545 years ago
Dont go for the DOTS
See the continuity of the RED and BLACK lines, they are all connected.
Got it?
its AC, so the correct signs would be (~) <---> (~), not (-) ---> (+)
qs6 years ago
Hi DP,

Without getting the design too complicated, you can maximize the flickering effect by doing the first "TA" as 1 leg, then the ending "TY" as the other leg, and mix the centre "S" with LEDs from both legs. In general, the further apart you separate LEDs from each polarities, the more obvious you will make the flicker.

Your mains is 50cycles, so each leg is actually running at 25cycles = more flicker than 30.

See the image below as an example: red dots would be + polarity and dark dots would be negative.
TASTY01.jpg
Dipankar (author)  qs5 years ago
Hi qs, How do I connect this to the mains? because LED's are a one way street.
qs Dipankar5 years ago
Use this schematic. Values in (brackets) are for US voltages. For added safety, add a 1N4007 diode in each chain facing the same way as the LEDs. This stops the reverse voltage to get too high should one chain stop working.
AC-Sign.jpg
netbuddy5 years ago
Where is the bridge rectifier and regulation? I hate to say it, if the output is only 12 volts, it is still AC and 240VAC or 12VAC, you can still seriously hurt yourself or even end up dead. Respect electricity, even a low voltage is dangerous.
12V netbuddy5 years ago
leds are diodes!
netbuddy 12V5 years ago
The have that property, too much reverse voltage and "POP" they go.
the simplest rectifier would be 4 diodes, one straight on every ac line (different directions) and crossed (same direction like the straight diode connection) connections to + and - because this isn't an asciiart-friendly board, ill have to try to explain: (~1) (+diode-) (-) (~2) (+diode-) (-) (~1) (-diode+) (+) (~2) (-diode+) (+)
oninkanin5 years ago
Hello Dipankar, i am Nino from the Phillipines, i an working in CBN Asia, i am the systems engineer here. I just want to say thank you for your design and your heart to publish it on the web. It is indeed a great help for us. I utilize your idea and make it as our lighting system on the studio. I made one color (white) only and put some gels for corrections. It is great and consume less power. What i am trying to work out now is how to make a multi color LEd lighting, any advise??? Anyway I dont know if you believe me, but surely what you are doing has eternal rewards. continue to share your knoowledge brother. THANKS!!!
treg6 years ago
I'm sorry to say that there are betters ways to supply power to the leds than using a transformer, you can make a current generator using just one condensator. Plus, adding a $0.5 diode rectifier would not hurt, and with another capacitor you would get a constant current source. The total cost would be about the same as the cost of the transformer (almost nothing), and you'd get twice more light and longer leds live. Anyway, I like the idea of the panel. I was planning to made one, I just could not find 5mm perforated fiberboard yet :D
Dipankar (author)  treg6 years ago
Dear treg, I am also sorry to say that your idea of condensator did not work out as I have used 160 LED in my next Instructable "LED CHANDELIER" which will be published in a few days. One condensator was unable to light up all the LED's and using more than one condenser becomes very costly.
treg Dipankar6 years ago
Is it possible that you share the precise schema you used ? I made a lamp with 120 warm white 25mA leds, using : -1 condensator to make an alternative current generator, -a diod bridge and a second condensator to get constant intensity, -6 lines of 20 leds (so the rectifying condensator don't get over-voltage if one of the leds get faulty) -6 resistors to match the luminosity of the 6 lines (and also lower the rush current). It worked perfectly (except that I did not like the "pure" white leds I hade) using the standard formula to calculate the value of the condensator).
Dipankar (author)  treg6 years ago
Hi treg, For lighting 120 LED's you have used ... 2-Condenser 4- Diodes for bridge 6- resistors Total 12 items. whereas for lighting 160 LED's I have only used one Transformer, thats all.
treg Dipankar6 years ago
condensers + diodes + resistors costed me 2€. Also, if I accept to have leds flashing at 50Hz (or 60), and not really care about a very little difference between the lines of leds (I could use only 2 lines and match the leds so avoid any difference, I used resistors because I have hundreds of them left and because I wanted to match different flavour of "white" leds), I could do with a 1.5€ condenser alone. The reason why I like the transformerless solution is because I can reach nearly 100% efficiency, with a cheap transformer, I assume to be at about 50% efficiency (or maybe up to 60-70 with a bigger / more expensive transformer). I also like this solution because it takes very few room. BTW, there are also reason why I do not like it (the main reason is safety : I make all my less-than-ten-leds using cell-phone charger than I usually find in garbage cans : safe and free. I would not let my 8 year old nephew play with my 120 leds lamp !)
remmelt treg6 years ago
Are you saying you have your LEDs hooked up directly to mains? There's a reason that's not legal. The reason is, it's dangerous. I don't think Dipankar's solution is perfect but at least he has separation between the light and the mains grid. Why not make a safe compromise with a transformer and a rectifier? That way you have safety and decent efficiency. Or you could buy a cheap wall wart and be done with it (but where's the fun in that!)
Dipankar (author)  remmelt6 years ago
Hi remmelt, SEE STEP-2 DON'T YOU SEE THE 12 VOLT TRANSFORMER. YOUR MOBILE'S BATTERY CHARGER IS ALSO PLUGGED INTO THE MAINS, is it dangerous? Look at the circuit Diagram. all modern equipments which are plugged into the mains use a transformer INSIDE, your PC , TV, Stereo etc. Where did you see the LED's are directly hooked to the mains. LOOK AGAIN.
Hey! I wasn't talking to you, clearly I can see your transformer :) Where I live (the Netherlands) it is illegal to hook up something like this to mains directly because it is unsafe. A transformer gets you separation between you and mains, which is good. Treg's solution doesn't offer that kind of safety, and that's why I responded. The mobile's battery charger is a transformer as well, and thus safe. Just don't touch the parts that are connected to the mains, but I guess we all know that ;)
Dipankar (author)  remmelt6 years ago
Hi remmelt, I am sorry, I misunderstood your comment. Now I see It was for treg.
1-40 of 47Next »