My wife had asked me to build a board or box with a bunch of levers, locks, handles, and doors for my two boys. I’ve always thought that it was a good idea, I’m just not that interested in things completely mechanical. So, I decided to build a button box that did essentially what my wife wanted while also being engaging enough for me to work on.
I did some quick google searches for such boxes, and found two. I was pretty shocked that I only found two, but I did find a lot of people who wanted to build this. It turns out that most people either didn’t have the time or the task became too overwhelming. Fortunately, I’m all about simplicity and I had a hard deadline!
I picked up a small tool box from a local electronics store, and an assortment of switches. I wasn’t sure what everything would do or how it would go together… I just wanted to make sure I had a variety of switches. I did already know that I wanted to make the red, yellow, green circuit from the other button box I saw, but that was it.
Once I had all of the parts, I created crude models in SolidWORKS and started to arrange them so the box looked and felt balanced. Once I started to layout where the buttons would go, I could start to see what each switch could do. Finally, I had it laid out and every operation figured out. Next, I spent a lot of time digging through my junk for the right LEDs and resistors (I really need to get an organizer). The motor and gear were from another project. Finally, I had all circuits figured out and designed for a 6V circuit. I wired, soldered, heat shrunk, and trimmed. Everything was assembled. It looked great!
I stopped by the grocery store on the way home to pick up some batteries and discovered that the battery holder actually holds 6 batteries, not 4! With this, the circuit is now running 9V! I decided to run with it anyway. Fortunately, I did put enough margin in the design to handle this, but I will fix this on the next iteration. Here is my first pass at it.
Things I’d like to change:
- Add timer circuit to shut device off after ~5 min
- Change alligator clips to banana plugs
- Find battery holder that can fit in the case (not attach to the lid)
- Cleanly cut holes for switches
- Add current limiting reset-able fuse
- Add silkscreen detail for fun