Lighting your Lego City?

[F0NIX]

Not sure where to put this msg, but since it is mostly house and street related I put it in the Town group.

I have for a long time wanted to put som light in the LEGO town. And had for a long time ago figured out how to do it, teoreticaly...

Had to collect enough courage to make some modification to some LEGO bricks. Normaly I try to stay away from that.

But I have bougt 200 lamp post 2x2x7 (part 2039) in white, trans clear minifig heads and 2x2 radar dish, to complete the construction.

Then I took a 2mm drill and made a hole from top to bottom. Bought a 3mm LED (this was a 3.2v 20mA 2000mcd Ultra Brigth White LED) and some thin wires. I cut a 9v LEGO electric wire with connectors in half and soldered a 470ohm resistor in series on one of the lead from the LED, the other straight on the other 9V leads. This is the final assembly:

Here is a sample image from a little "town" scenario:

I even tried putting a LED inside the chandalier (translation? Lysekrone in Norwegian) in the Grand Emporium set.

More pictures can be seen here:

http://www.brickshelf.com/cgi-bin/gallery.cgi?f=449085

[lightningtiger]

Very nice indeed 'F0NIX' - though 390 Ohm would do just as well, but of course heat is our main problem.....how is the temperature of the plastic lamps pieces after a while ?

In any case, I might just try one out.

I'm a conformist! !

[Piratedave84]

Ingenious, the setup is very nice and looks "stock" when incorporated in a display as your pictures demonstrate.

My big concern though is heat, after a while would the LED not fuse with the head piece? Or the continuous use change the color of the brick, would there be any yellowing of the trans piece?

In any case, I love the idea but could never resolve myself to modify a brick!!

Pirate

[kzv]

Nice idea... looks really nice when installed

I really like these types of ideas... Keep on!!!

My big concern though is heat, after a while would the LED not fuse with the head piece? Or the continuous use change the color of the brick, would there be any yellowing of the trans piece?

Pirate

Just a comment: The good thing with LEDs is that they are really effcient, meaning that most of the energy put into them will actually become light, not heat. For normal bulbs, it's opposite, typically 20% of the energy will be light and the rest heat. So I don't think you'll have any heating problems

kzv

[Gianluca Morelli]

Hi FONIX, this is a very nice mod.

I'd just like some help from you for the maths: when you put a 3.2V led on a 9V circuit you have to use a resistance to lower both voltage and current, right?

The formula is V =(R + Rled) * I, where V = 9V, R = 470 Ohm, Rled is the inner resistance of the led (unknown to me) and I is the unknown result.

Now, considering R >> Rled, I simplified in V = R * I or 9 = 470 * I so I = 9/470 = about 20mA. Ok, the current is lowered to a right value that doesn't fry the led.

But how do you know that the led is actually under 3.2 volts? I mean, starting from 9V you have 3.2V on the led and 5.8 on the resistance, but you can't choose the right resistance that allows this unless you don't know Rled, right?

(sorry for being a noob in electric stuff :-P)

Cheers,

Gianluca

[fred67]

This is fantastic... I've got a bunch of stuff that I've wanted to use for just such a purpose - LEDs, resistors, etc.

My problems include not having a drill press in order to drill such a small hole through such a long, thin lamppost (I even bought a bunch of those same lampposts), and dealing with wiring. I'm think that surely with such low voltage that you could use something like headphone speaker wire (where you have both + and - in a single wire), but I can't find anything suitable.

I'm also wondering how you managed to wire up your layout (without having the wires visible). I'm not adverse to cutting notches in some bricks to run wires.

For my former problem, I've actually been inspired by TGL itself with the Diagon Alley set coming out in January... I really like the lampposts they use, they are brick built, and looking at the pieces seem to have a hole top to bottom without any modifications.

Your layout looks great, I really need to get something like this done for my Christmas layout and you've really inspired me, FONIX - this is why I love Eurobricks, so many great and creative people.

But how do you know that the led is actually under 3.2 volts? I mean, starting from 9V you have 3.2V on the led and 5.8 on the resistance, but you can't choose the right resistance that allows this unless you don't know Rled, right?

Most packs of LEDs will tell you the voltage... mine say "2.9 min, 3.2 typical, 3.5 max".

Edited October 20, 2010 by fred67

[eiker86]

Nice idea... looks really nice when installed

I really like these types of ideas... Keep on!!!

Just a comment: The good thing with LEDs is that they are really effcient, meaning that most of the energy put into them will actually become light, not heat. For normal bulbs, it's opposite, typically 20% of the energy will be light and the rest heat. So I don't think you'll have any heating problems

kzv

FONIX started this project last week so i dont know if have done enough research to make an answare to the heat questions yet. if not i will start my LED right after work and see how it turns after a while.

[Masked Builder]

Very nice! Can't wait to see what you do with it!

[metalgearsolid]

I think it looks awesome! Unfortunately I'm not technically inclined tho.

Hope you don't mind that I've blogged about it here.

Looking forward to see more street lights!

[F0NIX]

Thanks for the comments.

To clear up some confusion about my choice of resistor value: first of all I was calculating using 12v supply (even if 9v is working fine). And with 12v I should use 440ohm, but then again it is difficult to find in a standard value so I selected the closest I could find in my drawer with various resistors, and it was a 470ohm 1/4w resistor :)

This is the formula to calculate the resistor: R = (Vsuplied-Vdiode)/Idiode = (12v-3.2v)/0.02A = 440ohm.

Or you can use this page: http://led.linear1.org/1led.wiz there you even get the color-code on the resistor. (It automaticly select the closest resistor value from the E24-range). The wizard also select a bit larger power (watt) size on the resistor.

The LED need 20mA and 3.2v to light up. The current will never exceed 20mA as long as it is working in room temperature. And to calculate the power (heat) in the LED you can use this formula: P (power) = V (volt) * I (Current) = 3.2v * 0.02A = 0.064W. And that is not much at all. I have run the 5 LED from a 9V LEGO battery box for three days continous up til now and I can't feel any heat at all from the LED's. They keep a steady room temperature. The power generated in the resistor is: P = (9v-3.2v) * 0.02A = 0.116w. And even with 12v supply it is only (12v-3.2v)*0.02A= 0.176w, and still far away from the 0.25w tollerance of the resistor. So heat is no problem. (The resistor is not inside a LEGO-brick).

And for those who are afraid of drilling up their lamp posts, it was actually a lot easier as I first feared :)

I started first with this type of setup: A 2L axle into a PF XL-motor, an 2x2 round brick with axle hole on to that axle, and then I could mount the lamp post on to that round brick again. The 2mm drill bit I secured in a small vice. Then it was just a matter of pressing the powered motor and rotating lamp post on to the drill bit, slowly. It seems like it mostly found the center of the lamp post by it self... well, when you used it carefully :)

But that worked too slowly so I used a battery powered drilling machine instead. Of the 110 done so far there was only 8 of them that I was a bit unlucky with and the drill bit got out on the side. But those was not too bad either, the hole is still completed from top to bottom and the damaged area can easy be covered with some white paint on the leads and no one will notice :)

Edited October 20, 2010 by F0NIX

[autobrick]

Pretty cool F0NIX. All you need now are light-up headlights for the cars/bus!

I think the only criticism (and don't get me wrong, I say this with full respect to your handiwork) is that, to me, the pure white LEDs are somewhat harsh looking. (Here is an example of what I am talking about). I think your town, especially the chandelier, would look a lot nicer with a softer glow. Of course there may be a reason why you chose the LEDs you did, or maybe you could just apply a filter to the LEDs?

Regardless, nicely done!

[CorneliusMurdock]

Wow! Can't wait to see an entire layout with these.

btw, you'll have to share the crime statistics of your lego city to show us if the crime rate went down after these lamps were installed.

[F0NIX]

Pretty cool F0NIX. All you need now are light-up headlights for the cars/bus!

I think the only criticism (and don't get me wrong, I say this with full respect to your handiwork) is that, to me, the pure white LEDs are somewhat harsh looking. (Here is an example of what I am talking about). I think your town, especially the chandelier, would look a lot nicer with a softer glow. Of course there may be a reason why you chose the LEDs you did, or maybe you could just apply a filter to the LEDs?

Regardless, nicely done!

Thank you!

Yes, as you say the light temperature on those Ultra Bright White LED's is a bit "cold" and bluish looking (color temperature is about 6500 Kelvin). I just bought those for testing, and was the only white LED's I could find in my town on short notice. I want some more warm white color for the next LED's (color temperature around 3000-4000 Kelvin). The bluish looking LED's would problably look very nice as headlights on a car or vehicle as they look more like todays Xenon lights for cars :)

I am thinking of buying some LED's from either Besthongkong.com or Elfa.se. But it is hard to find LED's with a warm white color in the 3mm size.

[fred67]

Along these lines, I'm wondering if any electronics tinkerers out there can suggest places to buy:

• Very small perf boards (fit in a 2x4 brick) (*)
  
• very small inline connectors with both +/-.
  
• very small coaxial wire.
  

I would also like to hook up an external power supply (a generic DC wall-wart with selectable voltages), so would like to see if I could find female plugs for that.

I've been buying at Fry's, but haven't been too thrilled with what they have (or the prices).

(*) Alternatively, is there a decent way to cut larger boards? I've not tried it, but it doesn't seem like it would work too well.

Edited October 22, 2010 by fred67

[broomhandle]

very nice lights! have you tried frosting one of the "clear heads"? to give it more of a soft light..

and, to keep the cost down have you thought of just buying the LED parts alone? not the lego version?

[BoobyToy]

Nice going Foinx!......Seems we think alike

I see that Fonix had the same Idea as me. I use just regular LED that I buy in bulk through some dealers on E-Bay. Here are links to my version of the Bike Shop and also The Grand Emporium that I'm slowly working on

7641 City Corner Bike Shop Pic 1

http://www.flickr.com/photos/boobytoy/4914467108/

Grand Emporium Pic 1

http://www.flickr.com/photos/boobytoy/4775804878/

ROOB

Edited October 23, 2010 by BoobyToy

[F0NIX]

very nice lights! have you tried frosting one of the "clear heads"? to give it more of a soft light..

and, to keep the cost down have you thought of just buying the LED parts alone? not the lego version?

I will try to put something around the LED that will dampen the light so it get a bit softer.

But I will also try out some LED's with other more warmer white color, but they are a bit harder to find in the 3mm size that I need.

What do you mean "just buying the LED parts alone"? This is no LEGO lights, they are custom made. I thought that came out clear in my descriptions...

I bougth some standard 3mm LED and soldered the leads and the resistors on by myself.

[Big Cam]

Awesome simply awesome. I wish I had the electrical background to set up something like this.

[sens1992]

Absolutely fantastic FONIX! Looks like you know your stuff! I wish I could set up something like that in my own LEGO city.

[simonwillems]

Great idea, I'll be following it in the process.

Being a purist myself I recently got into 12v trains and bought 14 of the old streetlights to incorporate in my town (set 7867).

The only problem with that (next to the fact that you need to get used to a not really beautiful looking lamppost) is the thickness of the cables. They are hard to fit... Maybe I'll switch to LED's some day.

[The Soup Nazi]

I the bike shop's lights. It looks like an actual store!

Edited October 23, 2010 by The Soup Nazi

[broomhandle]

I will try to put something around the LED that will dampen the light so it get a bit softer.

But I will also try out some LED's with other more warmer white color, but they are a bit harder to find in the 3mm size that I need.

What do you mean "just buying the LED parts alone"? This is no LEGO lights, they are custom made. I thought that came out clear in my descriptions...

I bougth some standard 3mm LED and soldered the leads and the resistors on by myself.

I would try a "Flat" clear spray paint, to frost a clear head.

and yes, sorry. i see that now. but do you have pics on how you tied it into the lego brick? is it a PF brick?

[F0NIX]

Along these lines, I'm wondering if any electronics tinkerers out there can suggest places to buy:

• Very small perf boards (fit in a 2x4 brick) (*)
  
• very small inline connectors with both +/-.
  
• very small coaxial wire.
  

I would also like to hook up an external power supply (a generic DC wall-wart with selectable voltages), so would like to see if I could find female plugs for that.

I've been buying at Fry's, but haven't been too thrilled with what they have (or the prices).

(*) Alternatively, is there a decent way to cut larger boards? I've not tried it, but it doesn't seem like it would work too well.

Depending on what you want to put onto that perf board, I would try to not use a circuit board at all and just solder the components together. A 2x4 LEGO brick is not big and just the thickness of a normal curcuit board is a little over 3mm.

I'm also intresting in a realy small inline connectors. I know of ways to make a realy small connector, but it is not "foolproof" and has no +/- directions. I am thinking of using connectors like these: http://www.computercablestore.com/High_Density_HD_D_Sub_Pin_PID157.aspx . They come in male and female versions. They are realy small and if you use some crimping insulation outside the lead it would work very well I think. I will try those out myself anyway as I have some avaiable at my work.

I do not know of any good coaxial wires beside the one you get for audio cables. If you have a RCA to RCA audio cable that has two small coaxial cables joined toghether, you could try to strip some of those. But I found those too large, and the "FKUX 0.08" wires I'm using is a lot thiner than a standard audio coaxial cable. The FKUX is less than 1mm in diameter.

Edited October 24, 2010 by F0NIX

[peterab]

I will try to put something around the LED that will dampen the light so it get a bit softer.

But I will also try out some LED's with other more warmer white color, but they are a bit harder to find in the 3mm size that I need.

You could just use trans yellow minifig heads, which I think would give the desired effect.

[kzv]

And to calculate the power (heat) in the LED you can use this formula: P (power) = V (volt) * I (Current) = 3.2v * 0.02A = 0.064W.

Well, this probably shouldn't be a discussion about technical aspects of the street lights, but I simply can't resist.

When it comes to heat; The above calculation is the total P and when it comes to heat it's only correct if all energy went out as heat and no light. But that is (obviously) not correct, since you can see the light So, the actually heat dissipation is much less than what you have calculated, since a LED is a very effective light source, not using to much power for heat, more for light (as we normally want, unless you hoped to use it as a small own... LOL)...

I also want to comment on the voltage vs current discussion. For a LED you normally don’t consentrate to much about voltage, it’s how much current you allow to flow through the LED that matters. That’s why all datasheet describe performance based on current! Well, then you could discuss that there’s no current if you don’t have voltage and so on.... My point is, if you concentrate on not putting more current through the LED than what the datasheet says, you’ll be fine

Having said all this “non-lego stuff”, I just have to say that I really like the lights , guess I have to do something similar...

Good work

kzv

(electronic engineer)