Slingshot Flying Pig Accelerometer

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My daughter, Sally, in addition to owning and operating a very successful horse riding school named Equine Kingdom Riding Academy, has a rather large eBay store she uses as a venue for selling items purchased at the local Goodwill "Bins" store. She often buys vintage toys with electronics features - sometimes working and sometimes not. A properly functioning vintage toy, be it a stuffed animal or a game of some sort, can make a huge difference in the resale price. When that is the case, she sends them home with me to attempt a repair. Many times the problem is corroded contacts from leaky batteries. A dental pick and some isopropyl alcohol usually solves the problem. When that doesn't work, it's time to open 'er up for a deeper look.

Over the years I have found problems ranging from dirty activation switches to broken wires to loose solder joints on circuit boards (a surprising amount of those). Some of the toys have incredibly complex electromechanical devices for moving limbs, mouths, and eyes. One doll I recently looked at had a wireless connection to a cassette tape deck that gave her voice and commanded her movements - that was a late 1980s vintage believe it or not. I don't usually spend a lot of time on any one item, but sometimes I get consumed in the chase and put in more effort than it is worth.

Occasionally Sally gets stuff just for the fun of it - like this Catapult "Flying Pig" toy. She gave it to Melanie as a memento of our latest trip to North Carolina. As the photo shows, a couple pieces of surgical tubing serve as the slingshot mechanism, and the pigs starts oinking when launched. There was nothing wrong with it, but I was curious as to the accelerometer that must trigger the oinking. Integrated circuit microelectromechanical systems (MEMS) accelerators are ubiquitous in today's world inside every smartphone and R/C drone, so I figure that is what I would find. Again per the photo, you can see it is actually a purely mechanical device that has a weak spring mounted inside a metal can that flexes and closes the circuit when accelerated. My second thought when seeing the construction (my first thought was, "wow") was that it looks a lot like a helical filter cavity. This is really more of a step back to 1970s design, but it works.

Posted May 15, 2019