Simple Spark Gap Radio Transmitter Buzzer

Designed for 7th grade STEM classes working from home during COVID.
1st learn the electromagnet
2nd make electrically controlled “tapper” “robot finger” that taps electromagnet when circuit is closed by human finger. Note essential gap between clip & electromagnet not too much but enough to move.
3rd make buzzer as shown in video not contact of 2 paperclips as path of connection. Tip: extending the springiness of the “tapper” as much as possible (longest free span) eases the electromagnet’s job.

Battery: 9V rechargeable are best use thick short rubber band to ensure good electrical contacts. Danger of overheating & running down the battery: be careful not to bridge any conductive material across contacts. Do not make permanent contacts unless the switch is in place.
Base: tape or embed parts into Styrofoam or something (can also tape parts to table)
Core: nail or something
Wires: can be aluminum foil for parts not contacting — if using for electromagnet must be insulated (can wrap foil in tape)
Switch & buzzer parts: 3 paperclips (large are best)