A fun hobby for electronic enthusiasts is making a flashing LED circuit board. You can use a flashing LED circuit board with other projects such as making flashing signs or billboards or building toys, robots, or Christmas decorations. Electronics manufacturers use LED indicators, such as those you see in servers, computers and network hardware. There are flashing LED kits available in the market, but you can also make your own so that you can create the pattern as elaborate as you want it to be.
Design a schematic diagram of your LED circuit board on your computer. You can use Adobe Photoshop or MS Paint to create your diagram. It should show the locations for the LED output, LED lights, ohm resistors, 9-volt battery and clip as well as the 555 timer. For a sample of LED flashing circuit design, see Resources below.
Print your design using a laserjet printer. Use a photo basic gloss paper to print your diagram. Cut it to the actual size of the schematic diagram.
Tape the printed photo paper on the perfboard. Cut the perfboad to size using the photo paper as your guide.
Remove the photo paper and then rough up the surface of the perfboard using steel wool. Use the steel wool to even out the edges of the perfboard. Wear a respiratory mask to prevent inhaling the toxic dust from copper.
Use a hot iron to transfer the printed design from the basic photo gloss paper to the perfboard. The plastic of the printer toner should stick onto the perfboard.
Remove the paper by soaking under water for a few minutes and then peeling it off to reveal the transferred design.
Etch the print on the perfboard. Dip the perfboard in a container filled with ferric chlorine purchased from the electronic store. Wear rubber gloves to prevent the stain from sticking to your hands. Agitate the container to submerge the perfboard inside the container. Ensure that the solution covers the perfboard completely. Leave it there for about 20 minutes. Constantly check and dip in a container with water to see if the copper is gone. Dip in solution again if the perfboard still has copper.
Use acetone to wipe clean the surface of the perfboard and remove any remaining ferric chlorine.
Drill holes into the perfboard based on the design where your LED lights will go. Use a drill press and 0.0350 etch carbide drill bit to make the right size holes.
Solder the parts using your diagram as your guide. Connect the positive to a negative of the LED wire connectors. Connect the UF capacitor, which will determine the speed of the blinking LED. You can choose from 10 to 1000 UF capacitor. Choose the one that would work well for your project. Connect the 9V battery to the battery clip then you are done.
There are LED circuit board kits available for sale that you can buy. You can use the ready-made LED circuit boards as a starting point so you can familiarise yourself with the different parts and their mechanisms. For more information on where to buy the kit, see Resources below.
Protect your work surface and your hands when you are using ferric chlorine solution. The stain is very difficult to remove, so make sure to wear rubber gloves and cover your table with plastic to protect it from stains.