1. Weld a vertical short iron pipe on the iron plate base, drill a screw hole in the middle, insert another long iron pipe, and weld a dozen small horizontal pipes with screw holes at the upper end;
2. Insert a long iron pipe with an electromagnet fixed at one end into a small horizontal pipe;
3. Screw a screw at the screw hole to fix the iron pipe, and fix a perforated aluminum sheet at the screw above (the aluminum sheet is not attracted by the magnet to the movement of the car), so that the device can be horizontally placed on the electric toy car where children play;
4. Connect the electromagnet to a circuit with two dry batteries as power supply, and connect a switch and a resistance protection circuit in series;
5. Magnetic switches are connected in parallel at both ends of the electromagnet to attract the ball, the reed switch is closed by other magnets, the electromagnet is short-circuited, and the ball will automatically fall, thus realizing automatic switching;
6, put the base on the electric toy car, put the small steel pipe on the base (the uneven end of the small steel pipe is the bottom, in order to facilitate the ball);
7. Turn the switch so that the electromagnet always attracts the ball;
8. Remove the magnet and get close to the reed switch, and the ball will automatically fall into the small steel pipe;
9. Take the ball out, then suck it with an electromagnet and turn on the switch at the bottom of the toy car. When the toy car runs stably, put the magnet near reed switch, and the ball can still fall into the small steel pipe.