Soldering LEDs + Other Adventures in Electricity

All the materials to make this happen, LEDs, 9v power adapter, resistors, soldering iron, etc

On Monday morning we set out all of the stuff that we figured we would need to start figuring out how to make an LED sign (+ some other things that aren’t really necessary for this project). We cut wires, soldered, used resistors, and mocked up a circuit on a breadboard and it was really, really fun. Lots of photos after the jump.

First step - cut off the end of the power adapter

First thing we had to do was secure our power source. I had ordered a 9v power adapter from Jameco, figuring we wouldn’t want to try to run this sign on a bunch of batteries, so we had to cut off the male end, leaving these two wires.

using the multimeter to make sure we were getting around 9v from the power adapter

We were a little nervous, but we put the two exposed wires into the multimeter and found we were getting pretty darn close to 9v.

We had some difficulty at first, figuring out how to make the breadboard work

Next, we tried to figure out how to use the breadboard. I had previously figured this out, but that was back in the summer, and I had forgotten which way things needed to be plugged in. You can see we have the 10mm LED, the 270ohm resistor and the leads from the power supply. The wiring in the above photo is incorrect though.

adjustments on the breadboard

We looked up some instructions, but something about them wasn’t registering with us, so we opted to just start experimenting some more. The wiring above was pretty close.

after realizing the LED was in the wrong way, positive and negative accidentally reversed, we fixed it and we had light

We realized that the LED was in the wrong way and that the resistor needed to be moved, then it worked!

we tested the resistor, all is well

We used the multimeter again and found we were getting 3.19v, which is pretty close to the rated forward voltage of 3.6v.

then we had to try two LEDs, and it worked!

Then we had to try 2 LEDs.

our first solder! resistor to LED

Then we decided to solder… soldering is really, really, really fun!

and then three LEDs

Then we had to try 3 LEDs, it was pretty awesome. 

then we started thinking about our first sign, we wanted to test to see how many LEDs might fit on the board

We also wanted to start doing some research about making an LED sign, so we printed some test text on 8.5 x 11 paper, layered a blank sheet on top and taped them together.

precision tool to start working on a prototype LED sign

Using an xacto knife with what was essentially a nail on the end of it, we started making holes for the LEDs. We wanted to see how legible the letters would be, depending on the number of LEDs we used and the spacing between them.

continuing with the LED sign prototype

Josh reasoned it would be best to work from the extreme points of each letter to get the spacing right.

continuing with prototyping

We tested a few of the letters, not the entire sign, as we would just have to take all the letters out eventually anyways. 

the completed prototype

We were pretty happy with how these turned out, and these letters used about what we were expecting—on average between 4 and 8 LEDs per letter.

measuring some plexiglass for an LED sign

Then we started thinking about making a real sign, settling on “Make Things Happen,” which would be mounted above my studio door. Though we meet in room 125, we weren’t sure about trying to mount a sign semi-permanently on cinder block. The width of the sign will fit perfectly above my door frame.

we're going to put this sign over top of my studio door

We’ll be continuing work on this at the next Office Hours, or next Monday, or both.

5 Replies to “Soldering LEDs + Other Adventures in Electricity”

  1. i’m glad that we got a lot done tonight. sorry if i was getting tired near the end. i don’t feel like i helped out much today. i’ll have the photos and video ready for you on thursday.

    1. hey Darren, no need for apologies, it’s tough to get everyone’s hands on everything… especially since we were just really figuring out what we need to do. I think that next time, we can probably do more soldering. But again, thanks for coming, can’t wait to see the rest of the shots!

  2. i’d love to help solder next time too. i just wasn’t sure what order to solder so didn’t want to mess it up. i think the photos are ok. i just need to remember to not get you in the shots with your camera. : )

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