[Demo]Health list buzzer manufacturer.

The buzzer is promoted by the manufacturer, and the buzzer is a kind of integrated electronic signal. It is used as a direct current voltage power supply. It is widely used in computer, printer, copier, alarm, electronic toy, automobile electronic equipment, telephone, timer and so on.

1. the buzzer prepared by the electromagnet M: in the length of about 6 centimeters of iron bolt around 100 loops of wire, the line end left 5 cm as a lead wire, with a transparent tape to stick the coil, so as to avoid the coil loosened, and then glue it on a box, the electromagnet is done.
2. the preparation of the bullet P: cut a long iron sheet of about 2 centimeters wide from the tin canned box, bend into a right angle, connect a lead wire of the electromagnet to the piece of cartridge, and then cling the piece to the board with a rubber cloth.
3. use a pin to make contact Q, use the book to raise the pin, and stick it with adhesive tape to draw out a wire.
4. adjust the distance between the M and the P (through the moving box), so that the electromagnet can attract the bullet and adjust the distance between the contact and the bullet, so that they can be properly contacted and the buzzing can be heard.