I DIDN’T KNOW THAT

Question: How can my electric toothbrush get recharged in its holder when there is no electrical connection?

Answer: It is charged through a phenomenon known as inductance. The end of the toothbrush contains a coil of wire and the base contains a matching coil. When the brush sits in the base, the two coils are close together, effectively forming a transformer. When an electric current is passed through the coil in the base, it induces a similar current in the opposite coil, which recharges the batteries. The base often has a vertical protuberance that passes into the center of the brush. This helps hold the brush in place, but it also contains an iron core that increases the efficiency of the induction process.