How to make an induction pen?

Induction pen, the high technology in high technology! ! ! Attention! ! Attention! ! Patent! !

Dismantle an old computer display screen, which is the glass of the computer display screen.

Usage: Hold the display screen, don't connect any wires, don't do any processing, and step on the wires. If there is electricity in the wire, there will be words on the display screen.

Advantages: the sensitivity is super high, and it can be measured without stripping.

Disadvantages: the sensitivity is too high to measure the voltage, only whether it is charged or not.