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To Solder or Not to Solder?

·2 mins

Welcome to a premiere here on “Ramp me up, Scotty!” - A hardware only project. Yay!

Before Christmas last year (2015) I was fed up with our broken door bell light. YES! Again, its all about lights, LEDs and stuff … since we are already at it.

So I went to the DYI and got a replacement bulb. Really old school thingy, no LED. Not that bright at all and too warm in color. This had to change. It was about time to warm up my soldering iron.

Those were the requirements:

  • Replace the bulb with a LED.
  • LED should be multi-color and change its colors continuously (it was christmas time).
  • The bulb is supplied with 12V AC, but the LED needs around 3.3V DC.

Some planning had to be done first. My electrical engineering classes were some time ago, but I still remember a few things.

I did the actual design totally old-school: On a piece of paper with a lead pencil.

But I took the opportunity to learn something new and downloaded the free version of EAGLE CAD and made a proper schematic.

EAGLE schematic

Check out this video on Youtube for a superb intro to Eagle for creating schematics: “Tutorial 1 for EAGLE: Schematic Design”

Actually, I did two versions, a pre-christmas and a post-christmas version.

The first version had a potentiometer instead of the resistor and the LEDs colors where constantly changing. Wonderful effect for christmas and with official wife-approval.

First version front side

First version back side

Here it is in action:

The colors don’t really show in that video, only at the border of that window for the name tag. The center looks white but it was colored as well.

After christmas, the first version had to be replaced with a white only LED to remain wife-approval. At that time I replaced the potentiometer with a resistor.

Second version front side

Second version back side

I have really enjoyed this small hardware-only project. Really like the fact that I can see it every day when coming home.

Here are some ideas for a followup:

Finally a pro-tip for creating diffuse lighting with LEDs: Take a rotary tool and grind off the round top of the LED to make it flat.

Done for today!