This tiny circuit is a simple way to make a fading led without having to program chips or writing code. Just a few simple components and you're ready to fade all day.
The end result is a constant fade up and fade down just like a Mac on standby.
Try it! See how small you can build it.
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Step 1: Gather Tool and Components
For this project you will need:
470 ohm resistor (or a resistor to drop the current for your desired led from around 8 volts.)
33k resistor ( or a 100k potentiometer for adjustable fade times)
LED ( I used Blue)
Generic NPN Transistor
Copper clad board. breadboard, or project board.
Dremel or other rotary tool for drilling
1/32" drill bit for wires
Cutting wheel or tin snips if necessary to trim board down
Scotchbrite pad or fine sandpaper. ( I used sandpaper because it happened to be there)
Muriatic Acid (concrete cleaner or pool chemical) Home Depot and other hardware stores have it.
Hydrogen Peroxide (standard wound cleaner) Found in drugstores, grocery stores, you probably have some at home.
Latex or Nitrile Gloves
Acetone to clean ink off of board after etch.
Outdoors area to etch in
Plastic or glass container to put etchants in.
Helping Hands clamp with magnifying glass (nice to have a third hand)
I've included the files for Express PCB software. Free download.