1、Teaching Tools: The kit is very suitable for teachers to explain the physics knowledge related to magnetic effect of current. Need to connect the bell to DC 3‑6V power supply. 2、Vertical: With a base, so that this experimental demonstration is more intuitive, and is easier for students to observe state of all compents and learning. 3、Principle: When the electromagnet is energized, it is magnetic, absorbs the armature, makes the dynamic and static contacts contact, and uses the magnetic effect of current to work. 4、When Powered on: Electromagnet can attracts the reed. When the reed moves to the magnet, the hammer strikes the iron bell to make a sound. moMoving plate and the static plate contact, and the current directly passes through the circuit to form a loop. 5、Eternal Ringing: When the electromagnet is powered off, the reed automatically springs back to its original place, the current re passes through the electromagnet, attracts the reed again, the iron bell continues to ring, and the electric bell is constantly rung.