Have you ever sat in bed, staring at a bottle of Iron III Chloride, and thought “I should do something with that…”? [Tobias] has. He wanted to use his tinkering skills to make his girlfriend happy, so he decided to make this beautiful etched PCB that professes his love to her.
The cool thing about this project is that [Tobias] has never etched a PCB, or even worked with SMD parts before! After designing the PCB layout on his computer, he printed it out on an inkjet transparency film and applied it to his PCB. After 14 minutes of exposure he then put the board into development fluid for about 60 seconds — it was starting to look good already! He then pulled out his trusty bottle of Iron III Chloride and began the etching process.
Once the board was etched, he soldered 18 red PLCC-2 LEDs in place, each with its own 330Ohm resistor. Not content with a simple on/off switch, [Tobias] decided to program a Trinket with a voltage regulator and mosfet to have it pulse on and off, similar to a beating heart! The finished project looks great, and we’re sure his girlfriend will love it.
Another bonus to doing something geeky like this for your loved ones means it will increase their acceptance of tools laying about, and half-finished projects that aren’t quite as pretty!
+1 HAPPY VALENTINE’S DAY ♥
I got confused by his writeup. Is he driving the LEDs with 5V or 8V? He implies both (“330Ohm to drive them with 5V” and “L7808CV”)
Probably a typo on the chip P/N. He’s driving it from a 9V battery, so there isn’t enough drop-out headroom for an L7808CV to be used properly (drop-out is typically 2V). When you consider the 5 and the 8 are adjacent on a number pad, a typo seems most likely.
Why are these things always put up too late for the day?
♥♥♥♥ +1
Maybe so the SO doesn’t see it before the day.
Not sure the SO (whatever that means) would appreciate getting it on the 15th….
Significant Other?
If his girlfriend checks his blog then she would likely see the project too early. Chances are she got it on the 14th and it just wasnt posted until later.
Special One :-)
Nice gift! The ultimate I think would be that she now let’s him build things on the dining room table. :)
Sit in bed with ferric chloride? I would not let that demon juice come near my bedroom!