Electronics Just Ordered 200 SMD LEDs off of Ebay

I'm going to make a miniature Ignignokt sign for in my car or somewhere

1206 SMD componets solder onto a .1" spacing prototyping board with ease, so I think I might actually get this project done sometime soon

oh and for those who havent heard of the news about boston,

these were placed around boston and 9 other cities, and 2 weeks later Boston PD is freaking out...

 

*** SMD. Can't wait to see it in action.

 

Have you sketched out a wiring diagram yet?

 

this should be amusing, good luck sounds gd!

 

I've played with SMD 1206 LEDS before, its not that bad at all even with a plain soldering iron. just tin the pads lightly, place the LED with tweezers, while holding it down with the tweezers, heat one pad, then the other. After that cools, add more solder to one pad, make sure that has solidified, and add solder to the otherside.

The tinning has enough solder to tack the led down, but I prefer a bit more to get a good bond.

1206 is actually a SMD size that most hobbyists should like. Need a decoupling cap for 2 adjacent power pins? get a .1 uf 1206 size SMD ceramic cap, solder it right to the pads.

I'm going to make a boost converter on the board for this so I can power the LEDs off of whatever source of DC I can get, batteries, my car or a PSU.

nope, not much to worry about as of now, when the LEDs get here, I'll solder them down and then figure out what my power circuit will be. Most likely a few parallel strings ~20v each string. Might add a 555 and make the middle finger blink

 

1206 is a fabulous size, I bought 2000 1206 leds the other day. I have a rather nice project involving these, in due course i'll show it. I have soldered 0805 well too.

Your soldering technique is exactly mine I suspect. Simply:
You tin one pad. You attach one side of LED to this tinned pad. Now its tacked down, so you solder the other side normally. It sounds the same as your technique from my interpretation.

Good luck!

 

I havent tried in person, but I suspect 805 would still fit on the pads and you could probaly still get to the holes. But these 1206 pieces are hard enough to handle I tin both pads just to make sure there is solder and flux underneath the pads, but one side is probably fine, I might try that as I'm soldering this up eventually.

In the works I also have a RGB persistance of vision display, using though hole RGB LEDs for that but I found some nice 16-channel 12 bit/channel LED constant current drivers from TI with a serial interface that I can cascade. So that should get interesting. Between that, and using a stepper motor for turning it, I think it should turn out nicely once I can get around to it

 

One of the mod sites for game console types make a printed circuitboard for surface mounts I'll try to find it. I ran across it when I changed LED color in my granddaughters wireless 360 controller. The circuit board in in straight rows and can be cut for how many sm leds you want to use. Might try googleing 360 controller mods if interested. Link later.

 

One of the things that makes a Gainclone amplifier a Gainclone is the very short negative feedback path. The trick is an SMD resistor across two leads of the LM1875 power amp IC, up near where they leave the chip body, a 1206 just fits.

 

cool, I'll have to poke around for that, it would be pretty useful for other projects, especially if it were flexible.

cool, but I have to be careful looking at small amplifier stuff I allready have enough projects on my plate.



autocad sketch of what it should look like, dont have it scaled there, but it will be .2" between vertical centers of the LEDs, and it will end up about 4.7" tall, so about the height of a CD

 

I prefer 603s :-D. 402 is starting to push it, though...

1206 should be no problem at all. You get a good deal? I was thinking of buying a bunch to make some 7-segment displays, in the spirit of the clock thread :-D.

 

pshhhhhhh, real men use 0201... (that hurts my eyes just thinking about it)

 

$.13/led (after shipping) for the green, and $.24/led for the blue after shipping.

I also picked up 50 RGB LEDs for ~ $.40/led after shipping, and a couple stepper motors. Also got an ICD2 and a programming socket attachement .
I got something neat planned, but its gonna take a while as I go though and refine each sub section of it

Real men dont buy IC's they buy dice and solder those right to the board

 

Ahh yes, I started doing this. But I soon realised that having that tnnned pad made it so the component was often not perfectly flat on the pcb. You get problem with LED's particularly then, because the maximum intensity angle of light isn't then perpendicular to the board. Its mere fussiness, although I find it alot quicker my new way.

Thats awesome, because depending how you move the POV display... you can have any resolution of full colour display!

 

The thing is, I'm serious. I use SMTs all the time, and layed down some 402s on square pad perf board yesterday. Granted, I was using some really good stuff (like a $4000 stereoscope), but still, after playing with those, 1206 feels like its as big as through hole.

 

oh i believe you. when i co-oped i had to solder 0805s and a few 0603s. i'd always grab like 3 extra b/c chances are i would burn at least that many up...

 

or sneeze, and lose them forever...

 

Ok, so I got the green LEDs in, and soldered those up, the design is too big for a single prototyping board, so I trimmed the edges of 2 of them, and I'll put them together.

The strip of material you see at the top there will get epoxied to the back of the 2 boards at the joint.

I decided to take a few macro shots....

overall of the LED, the solder looks funny on the ends becuase the copper contact is only on the U-shaped cutout on each end, not over the whole end.

little bit closer, you can see the die pretty good, its the red-orange-brown thing with the gold wire running to it.

trying to show the whole internal structure of the LED

I have a few other macro shots of small electronics if anyone wants to see.

 

Heh, nice photos. Those don't look nearly as small as I thought they would be.

 

Sneak peek at what I did with some of my LED's:
http://img.photobucket.com/albums/v14/macaba/sneakypeeky.jpg