On Friday, we were told to bring in any plush toy that had interesting innards that we would want to understand. Naturally, I picked out a stuffed bunny that has a switch on his foot which triggers a song to play, and two motors to start up- one in the body, one for the ears. Here’s a vid of mr. Rabbit before dissection time. I accidentally pulled one wire out at the end,but I found it’s connection and had the “bunny” in a fully functional state. Seeing just the motors, speaker, button, and battery working completely disembodied made me feel like some great robot surgeon. Poor bunny.
The most interesting findings in this specimen were
– the PNP/NPN circuit that reversed polarities every second of faster in order to make the ears go up and down
– the gear box that was inside the bunnies’ head was quite intricate, and contained at least seven differently sized cog wheels
– the fact that the PCB was made up of completely through-hole components. This definitely surprised me, as I thought surface-mount is much cheaper. Yury told us that factories are set up to do one or the other, and changing is more expensive than it would be worth.
I will definitely be salvaging both motors, as well as the switch (appears to be a small tactile one similar to what radioshack sells, only in a plastic encasement), and the 8ohm speaker that seems to be quite loud and clear for it’s size. Oh, and the battery holder is definitely something I can use- screws shut and holds 3 AAA batteries. Overall, very much worth the $12 (kmart had a sale on Easter themed plush!)