The device is built on an acrylic base about 60 cm in diameter, with 8 coils equally spaced around the ring. There is a wire track that the ball runs on. The device came with 8 steel balls, 4 large and 4 small. The included power supply is marked as supplying 24 volts and 5 A. Everything was completely assembled except for some minor damage as described below.
Though it was packed in polyethylene foam, there was slight damage from shipping. Not too surprising since it is shipped from China. The base and brackets are acrylic glued together. About 1/3 of the support brackets had broken off the base. This was easily fixed with plastic weld (methylene chloride) which I happened to have handy. I applied some to the joints with a syringe and held for 30 seconds to repair. One picture shows the repaired bracket, with the coil circuitry in the background. The 3 wire track rings have one junction each, and 2 of the junctions had come loose - again easily fixed with the plastic weld. The other picture shows one of the repaired junctions. After repairs, I powered it up and it worked great!
Each coil has an LED pair on one side to detect the presence of the ball. When the LEDs are blocked, current flows to the coil and the ball is accelerated into the coil. When the LEDs are no longer blocked the current shuts off. I found that the smaller balls would accelerate to about 45 rpm while the larger ones were about 150 rpm. It's pretty foolproof - there's no timing to worry about, since each coil has its own sensor. The ball accelerates until the losses due to friction equal the energy imparted every time the ball gets a kick from the magnet coils.
Satisfied customer, though I would recommend having some plastic weld solution handy.
