Those tiny motors run in DC. A coil can't output DC.
That thing is a tuned LC circuit. The NdFeB acts like a capacitor.
The center tap is an antenna.
Man-made and natural radio waves fill our environment. You're picking-up some local (1-20km)
radio or tv relay or station.
The tiny motor has at least one CR202x or smaller AgO2 cell in it.
The coil only acts as a switch and the internal bat is in series. The 9v bat adds current as it's connected in series with the motor and it's internal bat
tony6605 發表於 2012-11-28 06:38 PM static/image/common/back.gif
Those tiny motors run in DC. A coil can't output DC.
That thing is a tuned LC circuit. The NdFeB act ...