I'm a student teacher, practicing some physics teaching in a new classroom with old stuff in it. My teacher associate and I can't figure out exactly what this thing is. There's a coil, with a small electrode strip coming off the top, a pulley up at the top, a manual latch up at the top to let the carriage drop down, some dampening tubes for the landing, and a stack to add weights to at the bottom of the carriage. It can be used for PE -> KE conversion type labs, but I'm not sure what the point of the coil/electricity is?? We plugged it in for fun, unfortunately there were no cool sparks or anything ( ;-) ) But the coil did buzz, and the electrode vibrated. There's also a non-working tesla coil in the class, which I haven't taken out of the cabinet yet, and the teacher hasn't attempted to troubleshoot or fix yet - anyone with experience with these things?